E46 M3 Megane RS Brembo BBK Retrofit Install DIY

E46 M3 BBK Brake Bias Guide, Why The Megane RS Trophy-R Is The Best

E46 M3 BBK Retrofit Summary

  • Megane RS Trophy-R front / Porsche 996 rear combination is the best BBK retrofit option for E46 M3.
  • Megane/996 combo has the lowest deviation (0.5%) from stock brake bias while improving heat dissipation.
  • Megane uses 345x28mm CSL/ZCP/Competition rotors which are common and cheaper than true BBK alternatives.
  • Lots of brake pad options for Megane - same as 2017 Subaru WRX STi. (FMSI D1001)
  • Acceptable to pair Megane front with stock rear as brake bias deviation is within recommended specs.

What Makes a Good Braking System?

It is important to note that a BBK is not meant to maximize peak braking performance, rather it is used to sustain peak braking performance. There are many retrofit caliper kits available for the E46 M3 BBK however our goal here is to find the best available option for the E46 M3. We have long searched for a compatible radial mounted caliper that uses a pad size that works for the 345x28mm CSL rotor.

Sustaining Peak Braking Performance with Megane RS Trophy-R Calipers

Our research shows that the Megan RS Trophy-R is the best retrofit BBK to sustain peak braking performance for the E46 M3 considering the following two attributes:

1. Brake Bias

Brake bias “establishes the ratio of braking force between the front and rear wheels brakes” according to Formula 1 Dictionary. Simply how much of the braking pressure is at the front vs the rear? A balanced braking setup is critical to the car’s performance on track.

A more front bias setup will yield higher stability for braking but introduces understeer and can tend to lock up the front tires with too much front bias. Most OEM biases are front based designed for a bit of a compromise towards safety than performance. Most aftermarket setups yield a more rear biased setup which improves actual braking performance to a certain extent. However, the caveat to this is that too high of a rear bias can cause severe platform stability issues and can cause the car to rotate during high speed braking. Take for example in F1, drivers will set the bias more to the front during dry conditions, however they will change the bias to the rear during wet conditions to prevent front lock up.

2. Heat Dissipation

The braking performance actually stems from the brake pad itself, however when the pads overheats brake performance tapers down. This is where the benefits of a BBK comes in – larger thermal capacity in the caliper surface area to dissipate heat, more brake fluid volume, larger pad size heat dissipation and larger rotors. A BBK kit can longer sustain peak performance much more consistently at the track meaning more opportunities for more hot laps vs. cool down laps. A BBK kit in essence is analogous to an intercooler or larger radiator for your cooling system. Not much difference when the car is cold however when the car gets hot, the benefits are visible.

Brake Bias Comparison With Various Setups

On the E46 M3 we recommend about 2.5% max rearward bias deviation in any retrofit setup using our equations. For HPDE or time attack we recommend a slight rearward bias setup to maximize those hot laps and for racing events we would recommend closer to stock aka front bias for stability and lap time consistency.

ChassisFront CaliperFront Disc (mm)Front BiasRear CaliperRear Disc (mm)Rear BiasDelta from Stock Bias
E46 M3Stock32566.9%Stock32833.1%0.0%
E46 M3Megane RS Trophy-R34566.3%99632833.7%0.5%
E46 M3BMW E31 840Ci32567.3%99632832.7%0.5%
E46 M3BMW E31 840Ci32566.3%Stock32833.7%0.6%
E46 M3Megane RS Trophy-R34565.3%Stock32834.7%1.6%
E46 M3Aston Martin DB934568.5%99632831.5%1.6%
E46 M3CSL34564.8%CSL32835.2%2.1%
E46 M3BMW 135i34564.6%99632835.4%2.3%
E46 M3Porsche 99634564.1%99632835.9%2.8%

Our Calculation Methodology

Our previous recommendation of the Aston Martin DB9 retrofit used the EVO 9/X pad and that served as a good starting point for our search. One caliper that stood out was the Renault Megane RS Trophy-R caliper which used the same pad shape (D1001 FMSI EVO 9/X) as they are the same Brembo family as the Aston Martin DB9 retrofit calipers. We made sure the Megane RS Trophy-R caliper used stainless or aluminum pistons as we have seen cracking failures at the track with ceramic based ones such as 135i 6 piston calipers. 

The next step was to then calculate the brake bias using a simple general equation to see if this was a potential retrofit. Unfortunately, most brake bias calculators or equations will be off a bit due to unknown variables. We have looked at many online calculators from across the internet including community, professional, and scientific to see what the biggest contributors to brake bias comes from. This is our best attempt to normalize brake bias with derived values across all cars using the following values: size of disk, radial pad height, piston size.

From here we can derive disk radius, effective radius, total piston area which we use to generate what we call braking power index which multiplies piston area, disc size, and effective radius. I’d like to point out that the purpose of this is to compare the differences or deltas between brake bias rather than to accurately pinpoint the exact brake bias. Note that the CSL has a different brake bias however the CSL is tuned differently via suspension and weight which can play a role in braking. Therefore we prefer a more conservative approach using the E46 M3 stock brake bias which is proven to work as to serve as our goalpost. We simply don’t have enough data to accurately determine the actual brake bias. Instead, we are mostly concerned with comparing the estimated brake bias between stock and our retrofit kit using the same equation.

So What About the DB9 Retrofit?

The previous recommended Aston Martin DB9 retrofit kit yielded about 68.5% front bias and 31.5% or a 1.6% front bias deviation from stock brake bias. This is due to the DB9 kit having 40/44 piston sizes whereas Renault Megane RS Trophy-R has 40/40 piston sizes. So it’s similar. If you can find a set of the DB9 calipers, it should be a solid setup however it is very difficult to find a set.

More pistons the better right? Not necessarily, more pistons does not mean better performance as the piston area actually decreases if the pistons are a lot smaller. What actually matters is the total calculated actual piston area. 6 or 8 piston calipers usually have very small piston sizes in order to fit the caliper and to maintain brake bias. Another downside with having more pistons means that caliper size has to increase as well adding weight to an area which weight is not wanted or requiring bigger heavy wheels to accommodate the BBK. We find that most professional race teams opt for 4 piston calipers optimizing just enough braking performance for the weight. Most 8 piston calipers on the market are mostly for looks. Likewise with the size of the pistons, bigger is not always better as the brake bias needs to mesh well. For all these reasons, it is hard to find a well suited compatible retrofit caliper for any given car. 

Aston Martin DB9

Megane RS Trophy-R

E46 M3 Megane RS Brembo BBK Retrofit Install DIY

Final Takeaways

The Porsche 996 F/R retrofit is a thing of the past. Not to mention, the 996 front caliper is smaller in design, the brake bias is the worst, and requires machining for proper installation. The Megane RS Trophy-R is a better looking and better performing caliper that is from a newer vehicle. Our custom anodized brackets make this retrofit install easier than ever as it is 100% bolt-on. No milling, no intense searching on eBay to find a set of calipers. Enjoy OEM-like brake bias with increased heat dissipation for better performance on the track.

Megane RS Trophy-R Brembo BBK

Front Retrofit Kit – E46 M3

Shop Now

Additional Resources

Take a look at the various E46 M3 retrofit setups we've covered in the past.

Aston Martin DB9 BBK Retrofit for E46 M3 Review

Aston Martin DB9 BBK Retrofit for E46 M3 Review

The Aston Martin DB9 BBK Retrofit for E46 M3 is a new set up that I have been testing for the last few months. A few months ago we did a guide to do an Brembo E31 retrofit on the E46 M3, but this one is slightly different. Both are 4-piston calipers, but the calipers can be bought for a little cheaper than the E31. Nonetheless this retrofit is not very well known in the community, but it sure is a great one. I first came across the idea from Milla Bimmer on E46 M3 Owners Only Club on Facebook so a big shout out to her for letting me know about the kit. If you're interested in the market to upgrade your brakes, but don't want to spend thousands on a new kit, take a read.

Aston Martin DB9 BBK Retrofit for E46 M3 Review

What’s great about this setup is that the calipers do not require any machining and the adapter kit includes an upgradable bracket that allows for either stock 325mm or 345mm CSL rotors to be used. You will need the VagBremTechnic kit which costs about $260 USD shipped. VagBremTechnic is based in the UK and supply very high quality adapters and brake lines. From UK to California, I received my kit in 2 days upon ordering from them. This means no rust rings since the design fully sweeps for both rotor setups. The fitment is pretty much perfect and you can tell that detailed attention was paid to the machined parts. The piston sizes are well matched to the stock brake system with only about a 1.7% piston area decrease, meaning that the pedal distance/feel will feel extremely OE. It also retains the more of the stock brake bias with 40/44mm pistons compared to the much smaller 36/40mm pistons in the 996 front calipers. Technically, its a tad bit more front biased than stock brake bias than the 996 setup.

We are getting a lot of comments on the article's lack of emphasis on brake bias or too much emphasis on brake bias. These are my thoughts, I have tried out rear bias and front bias before in the past as well as mixing pads to adjust bias via the coefficients. There isn't anything wrong with oem brake bias or shifting bias to rears or front per say. As long as you can adjust compression and adjust your braking threshold to compensate. It is important to note balance is key at the track. Professional drivers will want adjustable rear bias before rears break traction to maximize braking zones but this is more of 10/10 driving all out. For majority of HPDE drivers, a neutral or slightly rear is preferred to maximize driver confidence instead in order to improve lap times as you will have a bigger buffer zone for mistakes while still having the ability to trail brake effectively. A setup that has too much front bias will induce understeer characteristics but a slight front bias would behave the same as stock bias. Either way, you can mix and match pads with different coefficients to get it just right. But for the general street setup, you want as OEM as you can get. -Oscar

Front Bias: High understeer characteristics

Slight Front Bias: Slight understeer characteristics

Stock Bias: Slight understeer characteristics

Slight Rear Bias: Neutral

Rear Bias: Snap oversteer characteristics

Bias Comparison (Calculator Courtesy of CLAWHAMM3R on m3forum):

Update 8/30/2019: User Mr. T-Rex suggested the calculation used for CLAWHAMM3R's formula included a 54mm front brake pad and not a 61mm pad, which it seems, therefore the stock ZCP ratio should be 1:76. This is not confirmed.

  1. 345mm DB9 + 996 Rear = 68.52% Front 31.48% Rear
  2. Stock M3 + Stock M3 Rear = 66.87% Front 33.13% Rear
  3. 325mm DB9 + Stock M3 Rear = 65.89% Front 34.11% Rear
  4. CSL Front + CSL Rear = 64.37% Front 35.63% Rear
  5. 996 Front + 996 Rear = 64.06% Front 35.94% Rear
  6. 325mm DB9 + 996 Rear = 63.91% Front 36.09% Rear

Front:  2004-2009 Aston Martin DB9 4 Piston or Audi TTRS 8J 4 Piston or Audi RS3 8P 4 Piston

Rear: Porsche 996 Base

Aston Martin DB9 calipers can be found on eBay for about $250 per caliper used or about $466 new on parts stores. If you scout eBay enough, you can find them for dirt cheap on the used market. You can also use Audi TTRS 8J model or RS3 8P model but you will have to flip the calipers since they are reversed from Audi.

The downside running the 345mm setup is that 345mm CSL are soft and do wear out quicker than most. You may need to replace them more often, but lucky for us, FCPEuro has lifetime warranty. OEM 18” wheels will require 16mm spacers per side for a 325mm disc, and 12mm for a 345mm disc. Unfortunately, there is no 355mm rotor pairing for this kit. If you want to upgrade from 325mm or 345mm rotors, you need to get the VagBremTechnic kit for the AP Racing 362mm rotors. This 362mm kit is quite costly and may not clear 18” wheels. We believe that optimal rotor size for the track should be 345-365mm; any larger may not yield much more benefit.

OEM 18" wheels require wheel spacers:
On the 325mm disc a minimum of 16mm per side
On the 345mm disc a minimum of 12mm per side & be cautious of wheel weights.

My Current Setup

  • Aston Martin DB9 Front
  • Porsche 996 Rear
  • VagBremTechnic Kit + 345mm CSL rotors
  • Carbotech XP12/XP10 track pads
  • Endless brake fluid
  • Titanium brake pad shims

Aston Martin DB* BBK Retrofit for E46 M3 Review

Caliper Performance

I went to test this setup at Streets of Willow on 10/28/2018 and was extremely pleased with the performance. Upon first lap, I noticed that the linear braking was drastically improved. I was able to extend in a much later braking zone over my previous E31 BBK setup due to larger rotors and pad size. There was zero brake fade and braking stayed consistent throughout all my sessions thanks to Endless brake fluid. When paired with Hankook TD C30 tires, I was very confident to brake at an excess of 1G, according to my Aim Data. I didn’t notice any pad knockback despite pulling close to 1.77Gs while cornering. I believe the titanium shims helped with reducing the amount of piston travel needed to contact the pad again. The increased rotor size of 345mm dissipated heat well and with just hints of glazing. The floating nature of the 345mm aided in weight reduction and made the vehicle more responsive to steering inputs.

This is by far my favorite retrofit setup with the 996 rears and is highly recommended for a budget BBK system. In comparison to the stock 325mm rotors, the 345mm CSL rotors are well worth the price in exchange for performance. Aesthetics-wise, these look visually bigger than the 996 front calipers as well. This setup has both form and function in my opinion.

Parts List

Below are the parts list for the DB9 retrofit. There are links included with pricing information, however we suggest you shop around with the part number (if given) to get the best current market price. As a side note, the DB9 part number has two X's at the end. These are variable letters depending on the color of the caliper - the part is the same. If you want to see the parts list for the Brembo 996 rear caliper, check it out on our Brembo E31 996 Big Brake Kit article.

Aston Martin DB9 Calipers

PartPart NameOrientationP/NPriceLink
CaliperAston Martin DB9 4 Piston (2004-2009)Right4G43-2C462-XX$465.63https://goo.gl/nBHtX8
CaliperAston Martin DB9 4 Piston (2004-2009)Left4G43-2C463-XX$465.63https://goo.gl/HZ2yjv
Rotor345x28 CSL RotorLeft34112282445$222.18https://goo.gl/ZpydJb
Rotor345x28 CSL RotorRight34112282446$222.18https://goo.gl/Nq5vbz
Brake PadAston Martin DB9 Front 2004-2009N/AFMSI D1165$220
ShimsTitanium Brake Pad ShimsN/AN/A$105.99https://goo.gl/p1XT5a
KitVagbremtechnic Front Caliper Carrier KitN/AAK0007$268.72https://goo.gl/D7oA3N

As listed on Vagbremtechnic's site, below are some of the available brake pads but not conclusive:

  • Pagid Road Front Brake Pad Set (T3132)
  • Mintex Road Front Brake Pad Set (MDB1859)
  • Mintex M1144 Race Front Brake Pad Set (MDB1859M1144)
  • Mintex M1155 Race Front Brake Pad Set (MDB1859M1155)
  • Mintex M1166 Race Front Brake Pad Set (MDB1859M1166)
  • Ferodo DS2500 Race Front Brake Pad Set (FRP3067H)
  • Ferodo DS3000 Race Front Brake Pad Set (FRP3067R)
  • Pagid RS4-2 Race Front Brake Pad Set (E2487RS42)
  • Pagid RS29 Race Front Brake Pad Set (E2487RS29)
  • Project Mu H16 Race Front Brake Pad Set (F906-H16)


B-Spec Tune

Update: Sport Plus Mode V2.1 for B-Spec Tune

 For those of you who don’t know about our current Sport Enhanced mode, it is an available feature with our B-Spec Tune where we remap your throttle response to become more linear and responsive to the driver. While the current mapping is already very responsive, we thought that it could be refined a little further and it’s safe to say we achieved that. As a result, we are happy to introduce our new and improved sport throttle mapping: Sport Plus Mode. 

This change may be difficult to notice, but compared to the previous Sport Enhanced Mode, pickup and acceleration from cruising speeds are much more responsive than before. There are three main characteristics of Sport Plus mode that differ from the previous Sport Enhanced: Torque Load Management, Electronic Throttle Duty Cycle Curve, and the WOT Threshold.

Improved Torque Load Management

A significant amount of torque load management system was flattened out in order to allow the car to feed in more power during heavy acceleration. This is to avoid the engine from being heavily filtered by the ECU’s torque management system. Additionally, the torque reduction becomes more linear as a result of the newly flattened curve.

Buildjournal B-Spec Tune Engine Torque Max

Buildjournal B-Spec Tune Engine Torque Filter

Buildjournal B-Spec Tune Dashpot Demand


Revised Electronic Throttle Duty Cycle Curve

We also modified the curve of the electronic throttle duty cycle in order to smooth out initial acceleration from lower RPMs. SMG drivers should notice more of a difference as this remapping should smooth out a lot of the jerkiness associated when accelerating out of a standstill.

Buildjournal B-Spec Tune Electronic Duty Cycle

Lowered WOT Threshold

We also lowered the threshold throttle values for the car to switch to WOT open loop map. This means that the car will switch to a WOT mode a lot sooner, which increases the perception of the engine’s instantaneous responsiveness.

Buildjournal B-Spec Tune WOT Threshold

Please note that the changes on Sport Plus Mode will not affect power gains or dyno curves. This feature release focuses solely on throttle response, acceleration and drivability of the car. This feature will replace the original Sport Enhanced mode, and be referred to as our Version 2.1. This is as a free revision to our existing customers for those who are wanting to update to Sport Plus. 

Note for existing B-Spec Tune Customers

In order for Buildjournal to continue providing free updates for your B-Spec Tune,  all customers must complete the Buildjournal Vehicle Compliance Waiver (which has also been emailed to you) in order to receive any future revisions of your tune, including this new feature. We have made some updates to our Terms of Service and Product Policy that all existing customer are required to review and acknowledge. We appreciate your compliance and understanding.

If you would like to update your tune with this feature, please do the following:

  • Send us an email with the subject line: [Order #*Put your order number here* / V2.1 Update] to [email protected]
  • If you have had re-tunes done in the past, include your most current B-Spec Tune that you would like revised. The free update is available for ONE B-Spec Tune file. If you would like to add the new feature onto some of your other files, a re-tune order will be required.
  • We will be focusing on our E-Flash customers first, and will start scheduling updates for our local customers once our queue has lightened up.
  • Note: We will be pushing out the revised files as quick as we can in the order that they come in. Please allow us some time to get to your update request as we may have follow up questions for you. To speed up the process, it is crucial that you follow all instructions and attach the correct files in order to be added to our queue. Thank you for understanding!

As always, we are always available to answer any other questions via email and don't forget to leave us feedback on our Facebook and website!

Titan7 T-S5

Titan 7 Forged Wheels Review

When looking for a track oriented rim, there are three things that come into mind: price, durability and performance. There have been many innovations in forged wheel manufacturing and understanding what new technology exists for forged rims is crucial in deciding for your next track rim. If you have read our previous article: Ultimate BMW E46 M3 Wheels Guide 2018, then you may be familiar with the criteria, how Titan 7 ranks 1st among the Tier 1 wheels.

During my quest to find affordable track wheels that didn’t leave my bank account empty, I came across Titan 7. I first saw them when I was at the track and spoke with several owners to learn more about these wheels. I was extremely surprised to hear that these were fully forged wheels, at under $2,000 for a full set. Immediately, I did my research and discovered that the owners of Titan 7 were some familiar names who are heavily involved in supporting the Motorsport community, with over 40 combined years of experience in wheel manufacturing. They have worked with many of the famous OEM wheel manufacturers, and built up a plethora of wheel manufacturing knowledge from the many years in the industry.

ManufactureRim MethodSizeWidthWeight (lbs)$/Wheellbs Saved Static lbs Saved*Price per lb Saved
Apex ARC-8RForged189.519.10$5957.7446.44$12.81
AdvanRZ-DF RacingForged18918.3$7008.5451.24$13.66
BBS RE-MgForged Mg189.516.7$215010.1460.84$35.33
Dymag MotorsportCarbon Fiber18914$237512.8477.04$30.82

Before diving into my review of these wheels, I would like to point out a few key points and wheel attributes as a basis of my analysis.


As mentioned before, Titan 7 wheels are fully forged. A forged wheel is able to reduce weight and result in a stronger wheel through a variable called porosity. Porosity is the measure of empty space inside of a material. For example, a sponge would have high porosity as there are many holes in the material. This results in a very soft product and easy to bend. Compare that with a katana sword, which is hand forged with a hammer. The hammering or forging effect reduces the porosity by forcing the metal alloys together squeezing out the empty spaces and aligns the material in the same direction or grain. As a result, the sword is a very strong and used to cut through other objects with ease. A forged wheel process uses a 10,000 ton press to organize the material grain and as you can imagine, significantly reduces porosity.

FEA Analysis

If you can’t tell from our previous articles, I’m a pretty technical guy. I need more assurance than just marketing and branding material to convince me that this company can create strong wheels. No claim can be supported without scientific data. That said, I spent hours learning the foundation of wheel manufacturing and production standards, and how Titan 7 meets them.

In the aerospace and civil engineering industry, products are assessed by a system called a finite element analysis, or FEA analysis. The FEA analysis is used to simulate stresses and forces in a realistic computer model that predicts stress points and failures. This is critical in discovering how a product might react to heat, pressure, vibration, material expansion, and more. This failure analysis demonstrates if a product will break in a safe way that is accounted for by the engineer. With advancements with technology and increasing affordability of this technology to wheel designers, this technology should absolutely be standard for wheel engineering.

James, one of the co-owners of Titan 7 (also a fellow E46 M3 enthusiast) states that every single Titan 7 wheel produced undergoes a FEA analysis. Not only do their wheels need to look good, but they also need to be extremely strong and meet production quality standards. All their wheels have been tested to meet all DOT/SAT and JWL/VIA standards. Upon the FEA analysis, they also do an in-house physical impact test where the wheel goes through real life stress tests to ensure that their simulations and analysis were correct.

He also shared some images from the FEA analysis that they undergo for each wheel. In the below images, you can see that 90% of the wheel is the darkest blue, meaning the strongest. Some other FEA visualizations I’ve seen from other wheel manufacturers showed that aesthetics were prioritized over engineering, with the entire wheel being yellow/red or not structurally strong.

Titan7 T-S5 FEA Analysis

A good, strong wheel is supposed to bend upon severe impact, but still hold air despite deformation. A weaker wheel will simply crack, which is extremely dangerous during a track day as it can lead to a serious accident. Unfortunately, this is a very common issue with replica rims. A copied design does not mean it has the same structural integrity or manufacturing processes that define the strength of the wheel.

For obvious reasons, this is why forged wheels are preferred for the track. They achieve mission critical safety requirements where life is at stake, while still offering performance benefits from weight savings. Additionally, further weight savings can be achieved through numerous optimization cycles in which extra material which is not deemed to be structurally integral to the wheel can be shaved off or removed. This is verified after the FEA analysis to ensure that the shaved material does not affect the integrity of the wheel.

Functional Aesthetics

Titan 7 has also introduced several new wheel design features which are pretty innovative. Not only are they aesthetically pleasing, but these features are also fully functional.

Gear Cut Knurled Bead Seat

Improves the bind between tire and rim. This prevents slippage and improves traction during cornering.

Titan 7

Rigid Spoke Tracer

Improves stiffness and durability of the wheel while keeping weight down. Increasing the ability to withstand wheel deflection or deformation at high loads improves consistency and feedback.

Titan 7

Reinforced Inner Rim Flange

This is a technology passed down from research and development in rally racing. The forged inner mass in the inner rim improves the resistance to bending  upon impact. This new technology was discovered by examining the correlation between the camber stiffness and how the wheel reacts. While this feature does add some weight, this inner mass adds incredible structural strength. We do note that some flow form and forged wheels will omit this feature in their quest for achieving a lighter wheel. However, omitting this technology feature will substantially increase the probability of bends or cracks at the inner barrel.

Titan 7


I have tested my set of 18x9.5 et 22 Titan 7 T-S5 on a set of 265/35/18 Hankook TD C30 and am happy to report the rims held up to the berms and dips (and my driving) of Buttonwillow and Streets of Willow. My biggest concern is always safety, this goes back to the wheel’s responsibility to bend instead of crack. While aesthetics is one of the first attributes that come to mind when looking at aftermarket wheels, many people often overlook the importance of a strong wheel. The difference between a strong versus weak wheel on the track is equivalent to going home with no physical injuries versus a totaled car with the risk of death. Can you imagine your wheel shattering on the track while going 100mph+ with zero control? Yeah, that’s a whole lot of no thanks.  Do NOT ever cheap out on safety, it’s not worth it.

Now that we’ve taken safety into consideration, let’s go back to how freaking good these wheels look. The designs are beautifully functional perfectly embodying the mantra of form following function. Small distinctive features such as their logo machined into the rim itself and all aluminum valve stems finishes off the end finish look well. They also clear my Aston Martin DB9 BBK and Porsche 911 BBK with plenty of space to spare.  

And do not forget about the price. Quality is important and all, but let’s be honest: we all know that price is an emotional determining factor when making a decision on wheels. As mentioned, Titan 7 wheels rank #1 in our wheel guide in the forged rim category for least expensive weight savings. Their pricing is about the same as a higher priced free flow formed wheel yet Titan 7 wheels are forged. There is little to no competition in this tier as there are not many forged wheel options even close to this price range. However, Titan 7 makes it possible to afford tier 1, lightweight but strong wheels. Otherwise, you will have wring your wallet out for some forged wheels from BBS, Volk, Advan, CCW, etc. Don’t be fooled by people who say “you get what you pay for” because you might just be missing out.

Physical product aside, I have also received incredibly transparent support from the team at Titan 7, who I have annoyed the hell out of with all these technical questions. In addition, they offer a limited lifetime warranty where they will work with you to identify any abnormal wheel issues should they arise, and get you taken care of. The fact that entire process from design, testing production is all done in house, Titan 7 is able to produce significant savings to the end user and results in quicker production times. 

Needless to say, I was convinced by the knowledge and data Titan 7 offered and I do not regret my decision to make these my track wheels. Great design, great price. For me, this was the most logical decision I could make for a set of track wheels. A set where I will not shrivel and cry in a corner if or when I need to replace them. I can feel confident, and most importantly safe in the event something unexpected does happen on the track.

If you are in the market for a track wheel, or maybe just a good looking DD wheel and some occasional track days, definitely consider Titan 7s. Just my two cents on the company and product, but visit www.titan-7.com and reach out to them directly if you have any additional questions.

[tg_youtube width="1920" height="1080" video_id="_epWcQDBFXY"]

If you have any questions let us know in the comments section below and make sure to follow us!

[tg_social_icons style="light" size=""]

BMW E46 M3 Wheels Guide

Ultimate BMW E46 M3 Wheels Guide

There are tons of aftermarket BMW E46 M3 wheels out there and if you’re in the market to buy you may consider things like brand, price, weight, etc., so we’re doing an article to review some of the popular E46 M3 wheel choices. Before we break down the wheels down to see which one has the best bang for buck, we’re going to explain the concept of weight in regards to rotational mass as that has a huge factor on track performance if that’s what you’re looking for. The brands we’ll be covering include Volk, BBS, CCW, Apex, HRE, VMR, Enkei, ESR, Gramlights and more. This article provides a basic insight into why strong lightweight wheels are highly desirable and yield such high prices. But first let’s dive into the basics of weight reduction and benefits.

Wheel Weight

There are different types of weights due to static, rotational forces, and spring dynamics. Each weight type will affect the car differently.

Sprung Weight

This is the total weight of all the parts on your car that is held up from your suspension such as engine, exhaust, body, and the interior of the car. Weight reduction is another way of “gaining” extra power. Simply put, less weight equals more power due to a lower weight:power ratio. This means that you will need less hp to drag the same amount of weight. You can very roughly estimate the amount of HP you have “gained” from weight reduction by using the equation in this article for sprung weights. Actual HP gain would likely be less than that value by 2-3% due to drivetrain and other losses here and there.

Unsprung Weight

This weight refers to the total weight that is not supported by the suspension such as the brakes, springs, shocks, links, axle, wheels and tires. Unsprung weight is important because the driving feel of the car is directly correlated with it. Driving feel refers to the feedback and accuracy from the wheels to the driver’s senses. The effectiveness of the suspension is dependent on the unsprung weight – less unsprung weight means that the suspension is able to be more responsive and work more effectively.

Rotational Mass

This weight includes the rotational weight of the car which includes parts that rotate such as the wheel, clutch, flywheel, tires, and drive shafts. Rotational mass affects the car’s ability to accelerate and decelerate. The further away this rotational mass is from its axis point or center, the effects are compounded and multiplied because of the rotational forces. This multiplier is known as the unsprung/rotational mass to sprung mass conversion. The general consensus for the E46 M3 is around a 4:1 ratio up to a 20:1 ratio difference between rotational/unsprung weight versus sprung weight. This means for 1lb of unsprung/rotational mass reduced, you are effectively reducing 4 lbs to 20 lbs of sprung weight.

This means that you should first concentrate on reducing unsprung and rotational mass for immediate performance gains. Lightweight wheels are one of the easiest (and aesthetically pleasing) ways to significantly reduce both rotational mass and unsprung weight at the same time.


Lightweight, Durable, Affordable. You can only pick two. Many of us have bent or cracked a rim before either on a pothole on the streets or hooning the car on the track too hard. Unfortunately, wheel manufacturers cannot satisfy all three criterias without making a sacrifice in one.

There are three types of aluminum wheels: Cast, Flow Formed, or Forged from weakest to strongest. The weakness of a rim usually comes from the porosity or micro holes in the rim material, a strong rim will have the low amounts of porosity. These are the construction types of wheel manufacturing that are used to form and create the wheel.

Cast Steel

Steel rims are usually used in spare wheel setups but may be found in budget aftermarket rims. These are cheap economical rims that are meant to be used temporarily as they are neither durable or light as their alloy cousins. Usually, most spare steel rims are extremely heavy so narrow widths are provided from the factory. OEM manufacturers use steel rims as spares as a result of their cheap production cost.

  • Weight: Very heavy
  • Durability: Not very durable
  • Price: $
  • Repairability: Easy

Cast Aluminum

Cast wheels are ones where molten aluminum (A356) is poured into a mold to create shape and form. This type of wheel manufacturing is the most basic process that uses pressure or gravity to move the molten aluminum into a wheel mold. Most aluminum alloy wheels are cast – either by gravity, low pressure, or high pressure. Most OEM economy cars use low pressure casting for stock wheels and which is very appealing to manufacturers as it is relatively low cost however due to its porosity (air gaps between material) making it crack easier.

  • Weight: Heavy
  • Durability: Medium
  • Price: $
  • Repairability: Easy

Flow Formed Aluminum

Flow Formed wheels are ones that are formed by both casting and pressure. The material used is the same as cast (A356 aluminum). This category includes rotary forged, liquid forming, spun rim, roto forged, flow forming, rim rolling, and free flow formed. In the manufacturing process, the wheel begins with low pressure casting to create the face. From there, a rolling forming machine is used to spin the wheel and heat the outer edge while applying steel rollers against the rim to form the shape and width. Alternatively to low pressure casting, higher pressure casting is possible through liquid pressure between 3000-5000 tons. The aim of applying pressure to the aluminum is to compact the material denser in order to reduce porosity and decrease the risk of the wheel cracking.

The heat, pressure and spinning simulates a forged process and results in a wheel with the strength of nearly a forged rim at a fraction of the cost. However, it is not a true forged process resulting in heavier and weaker structure than a fully forged rim. These wheels are commonly produced by high end sport car manufactures and high performance editions. Weight can be significantly reduced by Flow Forming technology as you will need less material to have the same strength due to structural rigidity compared to a cast wheel. Each wheel manufacture will have special variants of flow forming with their own concepts, but the main concept is the same among manufacturers.

  • Weight: Moderate
  • Durability: Medium
  • Price: $$
  • Repairability: Medium

Forged Aluminum

Forging is the process of applying thermal and mechanical energy to the metal’s internal structure – which deforms to the shape of the wheel. Forged wheels start out as a single piece of aircraft grade 6061 aluminum, which is then forged with a 10,000 ton press (one of the highest in the world) to give the wheel its shape, structural strength, and other beneficial properties. In short, a wheel manufactured with more pressure means it is stronger. The end product is one with improved durability and structural strength compared to a similarly cast version with less material, making it extremely light.

This method of manufacturing was passed down by F1 technology and research. Forged wheels are the best wheels for racers, but the immense tooling and machinery costs to manufacture these are the worst on wallets. As a result, only a handful of companies have the skill set, technology, and machines to produce these wheels. Like we learned in high school economics class, low supply and high demand calls for high prices.

  • Weight: Light
  • Durability: Excellent
  • Price: $$$
  • Repairability: Difficult

Forged Magnesium

Currently used in F1, magnesium material is used in order to save about 33% more weight over using aluminum. The density of magnesium is 1.78 g/cm3, this is 1.5x lower than aluminum and lower than steel by factor of 4.4x. However, magnesium strength is equivalent with aluminum and slightly less than steel. The true benefit of magnesium wheels is the inherent benefit of vibration dampening properties of magnesium and weight saving. Magnesium absorbs shocks or vibrations better than aluminum by over 100x and steel by 23x. This results in significant reduction of spring forces transferred to the suspension. Special care must be made when using magnesium as a material, only special forged processes will produce a strong enough wheel that will cope with demands of F1 racing also resulting in an very, very expensive rim. Such forging processes are secretive among the manufacturers. Common misconception is with the flammability of magnesium, this is mostly negated with the use of alloys. A notable downside is the rim’s weakness to corrosion which the industry have mostly resolved with surface treatment technology.

  • Weight: Extremely light
  • Durability: Great durability
  • Price: $$$$
  • Repairability: Extremely difficult

Carbon Fiber Woven

This is a newer technology so most of this process is a closely guarded secret by the very few manufacturers that have been involved in research and development. There are several different ways to produce carbon fiber wheels and companies are researching the strongest way and cheapest way to mass produce these wheels. Most carbon fiber wheels are used in hyper car manufacturers such as Koenigsegg. Carbon fiber wheels are about 20% lighter and stronger than forged wheels. These wheels however are one of the most expensive to purchase on the market.

  • Weight: Extremely light
  • Durability: Excellent durability
  • Price: $$$$
  • Repairability: Extremely difficult


Below is a chart that ranks price per lb of weight saving per wheel separated by wheel tier with tier 1 being the premium manufacturers. We have used the standard M67 E46 M3 18” rear wheel as a benchmark for further weight savings. We have chosen popular consumer wheels that are between 18×9 to 18×10 which is considered optimal track wheel setup for the E46 M3. We used the conservative ratio of 6:1 for the conversion from rotational/unsprung weight to sprung weight. According to various sources, the rotational/unsprung weight to sprung weight can vary from 5x to 10x. The comparison should scale to other sizes as well.

  • A lower $ amount means that a lower dollar amount was paid per lb saved.
  • A higher $ amount means that higher dollar amount was paid per lb saved.

Tier 1 Wheels

ManufactureRim MethodSizeWidthWeight (lbs)$/Wheellbs Saved Static lbs Saved*Price per lb Saved
Apex ARC-8RForged189.519.10$5957.7446.44$12.81
AdvanRZ-DF RacingForged18918.3$7008.5451.24$13.66
BC ForgedRZ39Forged181019.4$6507.4444.64$14.56
ApexARC-8R Forged181020.2$6006.6439.84$15.06
Apex EC-7RForged189.520.6$6156.2437.44$16,43
Advan GTForged189.519$8037.8447.04$17.07
BBS REForged189.521.3$7005.5433.24$21.05
VolkMagForged Mg189.517.2$17009.6457.84$29.39
WorkMeister S1Semi-Forged189.522.9$7703.9423.64$32.57
BBS RE-MgForged Mg189.516.7$215010.1460.84$35.33
Dymag MotorsportCarbon Fiber18914$237512.8477.04$30.82

Tier 2 Wheels

ManufactureRim MethodSizeWidthWeight (lbs)$/Wheellbs Saved Static lbs Saved*Price per lb Saved
ApexARC8 (ET35)Flow189.518.84$3148.0048.00$6.54
ApexARC8 (ET22)Flow189.519.2$3247.6445.84$7.06
Vorsteiner VFF-103Flow189.519.50$423.757.3444.04$9.62
WorkWork Meister S2RFlow18922.3$4254.5427.24$15.60
HardMotorSportSTW Center LockFlow189.524.5$4002.3414.04$28.49
HRE 447Flow181025.3$3751.549.24$40.58
BBS RS IIFlow181025.4$9001.448.64$104.16

Tier 3 Wheels

ManufactureRim MethodSizeWidthWeight (lbs)$/Wheellbs Saved Static lbs Saved*$/lb Saved
Enkei RP-F1 consumerCast189.517.2$3699.6457.84$6.37
OZAlleggerita HLTCast18919.6$3397.2443.44$7.80
AdvanRacing TC IICast189.517.5$5009.3456.04$8.92
BBSBBS RCCast181019.5$4007.3444.04$9.08
Racing Hart C2Cast181024$2752.8417.04$16.13
BBSRW IICast181026.3$6500.543.24$200.61

*We used the conservative ratio of 6:1 for the conversion from rotational/unsprung weight to sprung weight.

If you have any other wheel you’d like us to include, give us a comment below. And stay connected to our social!

New Features: Sport DSC Tune, Auxiliary Sport Fan Curve, Ignition Cut Off for E46 M3 B-Spec Tune

Your tune dollars are hard at work. We promised to come up with new and exciting features for the E46 M3 platform. Seems like there isn't much to do with this platform anymore, but we tinker a lot. We are pleased to announce three new exclusive BETA features to the B-Spec Tune:

  • Sport DSC Tune for MK20
  • Ignition Cut Off
  • Sport Auxiliary Fan Curve

We have tested these features extensively to ensure that these additional add-ons to the B-Spec Tune will not affect reliability of the tune itself. However, please note that your experiences may vary from car to car which is why we are releasing these as BETA features and may not be able to provide technical support on these features. These add-ons may not be applicable to all cars and are available to customers at your own risk.  If for any reason the features don't work, you can always flash your previous tune while we are continuing to develop. For information on how to get these updates, see very bottom of article.

Sport DSC Tune for MK20 (BETA)

Buildjournal's Sport DSC Tune will adjust your MK20 DSC parameters and ignition cut off so it is less invasive during spirited driving similar to M-Track Mode on the newer E46 M3s. Cars produced between 2003.5-2006 have the MK60 DSC unit which allows for M-Track mode, while older E46 M3 with MY of 2001-2003 are stuck with the older MK20 DSC unit. This MK20 unit doesn’t allow for M-Track mode to be enabled. While it is not an exact copy of M-Track mode, we have figured out a way to mimic some of the functions of it on the MK20 units that we will call Sport DSC Tune. This tune will significantly reduce DSC interference, but still keep it on in case of absolute emergencies. Keep in mind that driver experience will vary depending on different tire setups which is why we are releasing this as BETA.

Can I get Sport DSC Tune?

Because MK60 M3s already have M-Track mode, the Sport DSC Tune add-on is ONLY available for MK20 units on cars on MY 2001-2003 M3s. If you are unsure which DSC system you have, please see below.

If you see a DSC system in your top left "compartment" area, you have MK20. If it is empty, your DSC unit is near your intake manifold and you have the MK60 unit. The Sport DSC Tune will NOT work on MK60 unit and can cause quirky interventions if flashed on the MK60 unit. However, M-Track Mode for MK60 units is not made available from factory or by our B-Spec Tune. Enabling it requires some program adjustments - please email us if you would like to inquire about M-Track mode for your car. If you purchase the B-Spec Tune for your Mk20 E46 M3, you can the Sport DSC tune as an add-on feature on the order form. We will require a picture of the top left "compartment" under your hood to confirm you have the correct DSC unit. 


Why would I want Sport DSC tune?

The MK20 DSC unit is a relatively primitive unit that interferes much more than the newer MK60 DSC units. You may notice when you have a more aggressive wheel setup or tires, the DSC unit turns on more frequently than usual during aggressive driving or cornering. Even in everyday normal driving, MK20 units activate when it really shouldn’t. We have tested both the MK20 and MK60 on highway off ramps and noticed the MK20 unit activates about 40% more than the MK60 with the same wheel setup and cornering speed. With the Sport DSC tune, drivers to have the ability to drive aggressively while still keeping the DSC on for safety.

How does Sport DSC tune work?

Once Sport DSC is flashed onto your DSC unit, the new parameters will always be active while the DSC button is ON. We have designed this DSC tune to still use the ABS system and keep you safe in case of a complete loss of control. We increase the minimum amount of slip to activate DSC, and decrease torque intervention so that the DME doesn't suppresses as much power when the DSC does kick in. We also disable fuel cut off in favor of ignition cut as well.

How does Sport DSC tune affect normal driving?

Sport DSC does affect when and where the DSC unit reacts as it is prudent to relearn the limits of your driving in order to better predict and understand your DSC activation spots. However, it is not possible to have an on/off switch for Sport DSC. You will need to keep in mind that

  • DSC Button ON = Sport DSC, less intrusive DSC mode but still on for emergencies
  • DSC Button OFF = DSC is completely off. Drive with caution.
  • Opting in for Sport DSC means you will lose the factory DSC tune that is safer

With this in mind, we adjusted the parameters to be a tad more conservative. However, this does not mean that your car can defy the laws of physics. Please drive responsibly and only push the limits on the racetrack. We are not liable nor responsible for any mishaps with the abuse of this mode. Under normal driving daily driving, you should not see any difference in DSC intervention.

How does Sport DSC tune affect aggressive driving?

Under spirited drives, you will see a reduction in DSC intervention that may help with rotating the car through corners. However, if the slip angle is too much...DSC unit will still intervene mimicking the feature of M-Track Mode. Additionally, power will be consistently maintained even when DSC does kick in, as opposed to the factory DSC settings, where you will feel power bogging down or limited when DSC interferes.

Is there wear and tear associated with Sport DSC tune?

Yes, there will be increased tire wear from slip if you drive aggressively. Additionally, we deliberately kept the ABS parameters stock meaning your ABS system will still pulsate and actuate your braking system during DSC intervention. If you decide to add more power to maintain cornering speed during DSC intervention, it may wear out your brake pads as the ABS unit will try to counter the increased power. With the Sport DSC tune, the driver is given the option to power through and use up the brake pads in exchange for more cornering speed instead of having the DSC limit that. However, this is a choice that the driver will have to make as you can choose to let the car slow down enough to deactivate DSC intervention altogether.

Ignition Cut Off (BETA)

On the stock ECU, there are 2 stages of cutting power at the rev limiter: 1. fuel cut 2. ignition cut.

Fuel cut means that fuel will literally stop being injected when the fuel cut rev limiter is reached. This is useful for flat foot shifting - when you stay on the gas pedal while clutch is out when shifting to save time. What occurs is that the fuel cut rev limiter delays the power because of the fuel cut. 

Ignition cut off means that only the spark is removed to cut power and fuel will still be injected. This is more common among drag racing. Due to the unburnt fuel and air, the car runs richer at redline and can produce pops/flames on upshifts at redline.

For the E46 M3, there are two types of rev limiters hard and soft. The purpose of the rev limiter is to cut fuel to ensure RPM doesn’t exceed limits. The soft limiter doesn’t result in bouncing off the rev limiter and softly bogs the car down about 500 RPM like power is off. The hard limiter which is ignition based, you will feel a harsher cutoff but no bog.

To combat some misconceptions of the engine running lean on fuel cut, the effect of shutting fuel off does not lean out an engine. Engines will cease to fire the cylinder and the next spark cycle after fuel injection signal is stopped. The cool air passes through into the exhaust, and the O2 sensors will read it as pure air not LEAN. Temperatures concerning combustion do not rise and mixture does not detonate. No cylinders go lean or starve with the stock, 2-stage setup (fuel + spark).

What cut off do I choose?

If this car is your daily driver, we recommend you stick to the stock 2-stage fuel cutoff and use the raised RPM limiter to avoid fuel starvation at redline. It is by far the safest option for you and your engine. The ideal setup system for electronically fuel injected cars would cut fuel and spark, which the stock setup already does quite well. It is well balanced for reliability and performance.

For drag cars with launch control or race cars that need those few seconds shaved off, the less severe ignition cutoff at redline would work best, at the expense of additional wear on engine. Ignition based cutoff will run rich at redline in order to avoid bogging, but it does come at a cost. 

From our experience, this feature pairs will with our Sport DSC tune, specifically because the power is retained even after DSC intervention.

Is there wear and tear associated with this ignition based cutoff feature?

Yes, the obvious downside to this is that it can damage exhaust side valves, O2 sensors, catalytic converters and exhaust system due to the potential heat. You will also see fuel being dumped at redline. 

During ignition cut air and fuel will still be entering the combustion chamber. In absence of a spark, the car runs rich at redline. This could ignite, burble and shoot flames during upshifts.

As a rule of thumb, OEM manufacturers have overwhelmingly chosen 2 stage fuel/ignition cut over just ignition cut for the sake of car components. We are not be responsible for any issues you may experience from selecting the ignition cut off option. If you do not consider yourself an expert or at least well-knowledgeable about ignition cutoffs, we would recommend choosing the default stock option. Notice the fuel dump at the rev limiter of this dyno due to ignition based cutoff.

[tg_youtube width="1920" height="1080" video_id="V_rNxSZDcHk"]

Sport Auxiliary Fan Curve (BETA)

Sport Auxiliary Fan Curve is a feature that remaps your auxiliary fan (not your clutch fan). We re-scaled the curves that determines the auxiliary fan function for better cooling during idling in summertime traffic and while the car is resting between track sessions. While we do not have numerical data for this, it should cool down the car better during these two scenarios hence this being considered BETA. The aux fan is controlled by both voltage power and fan speed controller. We can see the comparison between stock curve and Buildjournal's revised curves for both voltage and speed.

Fan Voltage Curve

On the OEM graph, the auxiliary fan becomes less effective at high speeds and we see that the stock curve does taper off to half power around 78 mph. We revise this to let it run full power a bit longer for additional cooling.

E46 M3 OEM Aux Fan Voltage Curve E46 M3 Sport Aux Fan Voltage Curve

Fan Speed Curve

The auxiliary fan spins faster as the temperatures goes higher on the stock curve. We simply increase the speeds of auxiliary fan once temperatures are past optimal operating temperatures, leaving alone the lower temperature values as there is no need for additional cooling, and the aux fan is pretty loud.

E46 M3 OEM Aux Fan Temperature Curve E46 M3 Sport Aux Fan Temperature Curve

How Do I Update with New Features?

For all new customers, please order the B-Spec Tune on our page. For all existing customers who would like to update their tune with Sport DSC tune, please email us at [email protected] with your Order # and a photo verification of what DSC unit you have. All requests must be made by email. We will not monitor tune requests outside of email. For all existing customers who would like to update their tune with ignition based cutoff, please email us at [email protected] with your Order # and why you would like to add this feature. For upcoming features and change logs make sure to visit our Future Research and Developments page.

E46 M3 E85 Tune - Buildjournal B-Spec Tune

Ivan's E46 M3 B-Spec Tune x AFD E85 Flex Fuel Kit - Dyno Results

Ivan came to us for a B-Spec Tune about a week ago to give his beautiful alpine white E46 M3 a little bump in power. A few days later, he took it in for a dyno session and came out with an awesome 305.70 whp/ 257.74 wtq on California 91 pump gas. Although we were pleased with his tune results alone, we also advised him to look into pairing the B-Spec Tune with flex fuel E85 to see what additional performance gains he could make while being catted. He later read our E46 M3 E85 Review & Dyno and decided to try out the AFD Proflex Commander E85 flex fuel kit after our suggestion. The results? See for yourself below…

Ivan’s 2002 E46 M3

E46 M3 E85 Tune - Buildjournal B-Spec Tune

  • B-Spec Tune (catted)
  • Advanced Fuel Dynamics Proflex Commander Flex Fuel Kit 
  • Stock Euro headers + Euro catalytic converters
  • eVenturi with updated cone filter
  • Relocated TMS IAT temperature sensor
  • Mishimoto silicone intake elbow
  • Mishimoto electric fan conversion and stock fan delete
  • 6MT (SMG conversion by Kaiv)
  • 111k miles on odometer currently
  • Rod bearings and new cooling system was installed at 100k miles


Ivan’s car dynoed a whopping 334.94 whp/ 265.33 wtq with B-Spec tune + AFD Proflex Commander with just E57 fuel. An impressive peak to peak gain of +29.24 whp / 7.59 wtq compared to B-Spec on California 91 Octane. Here we can see that E46 M3 really takes advantage of the higher octane fuel with a tune and it is evident that the E85 helps stop the S54 DME from pulling timing. Also, notice the healthy curve gains throughout the entire power band and how the jagged lines starting at 6.7K RPM are smoothed out up top. You can read Ivan’s full review on M3Forums.

E46 M3 E85 Tune - Buildjournal B-Spec Tune


“The car put down a whopping 335 whp. Wait, whaattt?!?!?!? Yup, 335 whp. Holy hell!! Steve and I were so shocked that we did 2 more runs, still 334-335 whp with very consistent curves. I am simply blown away.” – Ivan

*Remember our 10% coupon code for AFD Proflex Commander for E46 M3 is only valid until 5/31st! Use code buildjournal at checkout.

E46 M3 E85 Tune Dyno

E46 M3 E85 Review & Dyno: Advanced Fuel Dynamics PROFLEX Commander

For those who don’t know, I have been working with the folks at Advanced Fuel Dynamics to review their PROFLEX Commander Kit for the E46 M3 N/A application in order to run E85 fuel in the E46 M3 stacked on our B-Spec Tune.  Advanced Fuel Dynamics was founded by Ryan Truax, a highly regarded E85 tuner for high horsepower cars in the motorsport world. He developed AFD and his flex fuel kits due to an issue that he consistently ran into when trying to create E85 based maps: E85 fuel was never consistent at the pump. This lead to efficiency and consistency issues as the E85 fuel was never consistent with the tuning. As a result, E85 tunes would have to be extremely conservative, essentially negating the power gains that running E85 is supposed to provide not to mention dangerous.

After some research his team discovered that E85 at the pump could vary between 51%-83% ethanol. Additionally, when developing the kit for the E46 M3 he saw that the E46 M3 would have differing ethanol percentages every fill up for the first 20-30 miles because of different separations in the tank. With so many variables surrounding a stable ethanol number, he instead developed an unique plug and play system that would account for changes in the ethanol content specific to each car called PROFLEX Commander flex fuel kit. 

What is E85 and Why Do I Want to Run It?

E85 stands for 85% Ethanol and 15% gasoline. E85 is a 104 Octane fuel alternative to gasoline. Ethanol is the best performance fuel out there if blended, used, and tuned properly. Ethanol is an octane enhancer because it is a great oxygenator and acts like a solvent that cleans fuel tanks and lines.  Most modern ECU have a trim allowance to accommodate 10%-15% ethanol to adhere to gasoline standard of containing up to 10% ethanol. However, a flash tune or flex fuel kit is required to go beyond ~E20 or 20% Ethanol. Failure to do so will run your car very, very lean. The closer you get to E85, the more performance benefits you will see.

Ethanol benefits:

  1. Power: Helps the DME from pulling timing, resulting in more power and smoother delivery. This creates faster flame speed and oxygenated fuel More air = more power
  2. Environment: Lower emissions due to fewer carbon deposits
  3. High Octane: 104 Octane
  4. Cooling: Ethanol doesn’t allow heat saturation and has a cooling effect due to alcohol properties
  5. Cleaning: Cleans valves and pistons because it condenses fuel thus achieves a cleaner burn across entire cylinder
  6. Price: $2.00/gallon on average, with the occasional E85 day courtesy of Pearson Fuels ($0.85/gallon!)
  7. Smell: E85 is not nearly as pungent or strong as gasoline – especially if you are running catless. The smell is hardly noticeable and instead smells somewhat “sweet”

E85 Ethanol Myths Debunked

Ethanol will eat my fuel lines! E85 is not corrosive, it is actually a cleaner. The blend has a lot of lubricants from the other 15% gasoline and additives in that special gasoline blend. The corrosiveness lies within the gasoline portion of the E85 called the aromatics. This causes the permeation or corrosiveness. With that said every modern day car is designed to handle some amount of ethanol in the fuel system due to fuel standards in the United States.

Ethanol attracts water into the fuel system! Water is introduced by temperature variations which causes condensation. E85 Ethanol is hydrophobic so it is not any more hygroscopic than gasoline, meaning that it does not absorb that much moisture from the air. The difference is that an E85 blend is designed with this in mind vs pure Ethanol. In E85 fuel, ethanol will suspend and carry the water but not actually absorb it. Majority of the water is already in the gasoline portion of E85. When this separates, this is where issues happen. Legally, 2% water is allowed in the fuel. The problem is that moisture comes from the other additives mixed in with the ethanol.

In regards to the separation that I mentioned earlier – E85 ethanol does not have affinity to water. However, when E85 sits for too long with headroom, it will tend to separate into 3 distinct layers: gasoline, ethanol, and water from top to bottom. Complications can occur when water hits the spark plugs first. This is the reason why blending is such a crucial stage of your fuel delivery system. Keeping the fuel in motion via the fuel regulator will mix the fuel, reducing the chance of separation. All observations noted above applies to gasoline as well. To avoid this, fuel stabilizers have been developed keep the fuel blended and avoid separation.

However, this is not to say that it is completely unsafe or dangerous to start a car that has been sitting. It is just a good general practice to be wary of the fuel separation phenomena – AFD has tested cars that sat for 7-8 months with pump E85 and starts up just fine.

Ethanol will instantly destroy my engine, fuel pump and injectors! Ethanol will actually prolong the life of your motors. However, there is some truth to the fuel pump and injectors working harder to compensate for the higher fuel demand. The duty cycles and pulse duration are increased when car uses E85 fuel. In short, the increased wear and tear on the fuel pump and injectors will result in a slightly shortened life.

E85 has worse MPG! This is technically true – not because lower energy level, but because the fuel system literally demands more E85 fuel itself. This is offset from the cheaper cost of E85 and performance gains. To see the difference, compare miles per dollar.

What is PROFLEX Commander kit?

Advanced Fuel Dynamics PROFLEX Commander E85

Simply put, the PROFLEX Commander kit is a full bolt on performance flex fuel system that allows for all mixtures of E85 and 91 blend. They have kits for many makes and models, but we are reviewing the one made for the E46 M3 specifically.

The kit plugs into the OEM injector wires through a harness and replaces the factory fuel lines in order for your car to allow for any mixture of E85 fuel without any other hardware changes! The flex fuel sensor is located after the regulator right before the fuel rail so that an accurate ethanol reading is sent back to the Commander unit. The Commander unit will dictate how much fuel should be sprayed by the injector based off the flex fuel sensor. The Commander unit also detects startup and runs a special procedure in order to achieve a stable cold start idle. You can also monitor ethanol content through their mobile app via Bluetooth connectivity on their flex fuel sensor. Install is fairly straightforward and takes about 1-2 hours for the DIY capable. DIY Guide coming out soon, stay tuned!

What does PROFLEX Commander kit include?

  1. PROFLEX Commander Unit that is specifically designed for the E46 M3 S54. In essence, it is a secondary brain that manages the E85 fuel injection, cold starts, and monitoring live ethanol data.
  2. Flex Fuel Sensor. This sensor has a bluetooth connectivity so that you can monitor your ethanol percentages right on your phone!
  3. Plug and Play wiring harness for S54 engine. This harness is professionally made, very high quality harness that plugs right into your OEM connectors.
  4. E85 Compatible Fuel Lines with Quick Connects that connects to OEM fitment plugs for E46 M3.

Q: Don’t I need an E85 fuel pump or upgraded Injectors?

A: No. According to AFD, their kit is specifically designed for the E46 M3 OE fuel pump and OE injectors.

Q: Will I run correct AFRs and will fuel trims be affected?

A: Yes. With this system, the car will always run correct AFR at any blend at any throttle position even with a pump gas tune like B-Spec. There is no dead time at high rpm and the fuel trims will not have to compensate based on rpm or load. Fuel trims might change a little bit initially due to their system accounting for the ~10% in regular fuel, but other than that there won’t be changes during normal operation. PROFLEX system is also not reliant on the O2 sensors.

Dyno Testing

The dyno testing was done to measure the power difference between a 91 octane on B-Spec tune and AFD PROFLEX Commander with E70 mix stacked on our B-Spec tune. AFD claims 20whp gain. But does it really gain that much?

Disclaimer: AFD sponsored us the PROFLEX Commander Flex Fuel Kit for review.

Before we dive into the numbers, there are a few important things to mention so you have a full understanding of the results. See below for the notes:

  • Test car for both runs is Oscar’s TiAG M3, not Andrew’s AW M3. So baseline is different.
  • Mod list for both runs:
    • Stock airbox has a BMC panel filter
    • Macht Schnell Intake Elbow
    • F1 Autohaus Ceramic Coated Header
    • SGT V1 Exhaust
    • B-Spec Tune
  • Running Chevron 91 ACN octane and E70 mix without ANY additives or octane boosters to simulate real world environment
  • All dyno runs done with hood open

European Auto Source is our choice dyno facility to ensure consistency as we prefer to do testing on the same dyno with the same operator, Steve. The 91 octane run is one of my healthier runs from late last year under cooler conditions, and the E70 run is from 4/28/18 around ~ 85 degrees F ambient temperature. 

The results? End result with AFD + B-Spec + E70 was 315.25 whp and 243.80 wtq, the B-Spec + 91 was 295.85 whp and 239.87 wtq.

After doing several runs we saw peak-to-peak gains of +19.4 whp and +3.93 wtq.  The dyno video shows fuel being dumped as I was testing Ignition Cutoff feature for an upcoming B-Spec tune new feature, it is normal trust me!

Advanced Fuel Dynamics PROFLEX Commander E85 - E46 M3 Dyno

We noticed that the 91 octane run dropped off early at 7.3K. We believe the culprit is the quality of the 91 octane fuel and the car was pulling timing due to the poor gas. I did the cardinal sin of filling up while a tanker was filling up the station tanks, however I was late to the EAS dyno appointment. It is common to see the S54 pull timing at higher rpms when bad gas is used. California really gets the short end of the stick too – all the more reason to switch to E85. Even then, we predict that on high quality 91 octane fuel it would taper to about ~300whp (we have an older dyno sheet for Oscar’s TiAg that did 297 WHP before on better 91 gas (Shell V Nitro+). Notice the E70 tapers much better at the higher rpm which means car is hitting timing targets.

This would still net PROFLEX Commander a 15whp+ gain using the older dyno numbers. Very impressive indeed.  

Advanced Fuel Dynamics PROFLEX Commander E85 - E46 M3 Dyno


This is a E46 M3 dyno chart on a Mustang dyno published by AFD and you’ll notice it is very similar to ours. Note that Mustang dynos (AKA Heartbreaker dynos) will have lower numbers than a Dynojet because they put more load on the wheels. We are primarily interested in the deltas and shape of the curves for comparison.

Our stock BMW E46 M3 test car put out a baseline 270HP on pump gas. After plugging in our PROFLEX Commander and adding E85 the car made 291HP on 75% ethanol. The 21WHP gain is felt across the entire the entire rev range, making the car faster both low and high in the RPMs. The customer feels a notable difference when running E85 over gas with the PROFLEX Commander. -AFD

Advanced Fuel Dynamics PROFLEX Commander Review

The primary reason I reached out to AFD was because I was intrigued by their claim that the kit works with any tune (and because I’m already running E30 on my F30 335i). I’ll admit I was a bit skeptical at how knowledgeable they were to make a claim like that.

I had the opportunity to speak with Ryan, William, and Dan from AFD and immediately felt relieved within the first 5 minutes of our hour long call. These guys are very experienced, knowledgeable, and technical about tuning and E85. Their “Ethanol Experts” have experience in tuning race cars in the motorsport world such as high horsepower evolutions/speed boats/open seaters and fully understand the science behind ethanol and all of its properties.

I have tested this kit stacked on top of our B-Spec Tune out for 4 months to provide a full, comprehensive review. In this time, I have autocrossed, tracked, and drove long distances in order to really put the kit through its paces. Here is how I would rate the product in price, performance, and quality.


The Advanced Fuel Dynamics PROFLEX Commander Flex Fuel Kit runs for $800 retail. Considering the hp/$, this kit is very reasonably priced. The only reason this did not receive full points is because it is not technically a “steal.” Those who truly want to go E85 will find that the benefits of the kit will justify the cost, and in-time, the cost-savings of running E85 will add up. Take advantage of the limited time discount code at the end of this post!


The material that the commander unit, sensor, and harnesses are high quality materials. They were very similar to OEM grade. The fittings were perfect and require no trimming or modifications.

In terms of reliability of the product, I have had no issues related to the kit at all in the 2,000 miles I have driven it. I have run many mixes between E30-almost full E85 from mostly Shell and Chevron. Octane levels are all different at each station and could sometimes have “bad gas”, but the PROFLEX kit takes care of that for me by automatically adjusting to the ethanol levels. Their mobile app to monitor what ethanol mixture is in the tank is extremely accurate and useful for me to keep track of how much and what’s in there.

Cold start has also been perfect every time in the last few months. AFD really did their homework as cars are known to have a hard time starting up with E85. The idle is consistent and stable with no hiccups or hesitations in power delivery which would indicate fuel pump or injector issues.


The power gains are addicting. On the track/autocross, the car felt great throughout the entire day with no cooling issues. The MPG was predictably worse meaning I had to refuel early but the performance it’s definitely worth it. The E85 helped with the B-Spec Tune timing targets, and I could feel the car meeting the targets even under high heat. This told me that the cooling effects of E85 was working and higher octane meant that timing was more consistent at high rpms. I could tell when accelerating out of turns and on the straightaways that the car pulled much harder and smoother than on 91 octane.

My Conclusion

In short: the AFD PROFLEX Commander kit makes power both safely and reliably. The kit retails for $800 and in our opinion, is well worth every penny. And while the performance gains are amazing, lets not forget about the ease of use and the overall improved driving experience.

Flexibility: E85 is not as abundant as regular 91 octane, which can be a hassle if you have to run strictly E85. One of the greatest benefits of AFD’s PROFLEX kit is that it will adjust for any amount of E85 and 91 octane. That way, you can still fill up with normal 91 octane whenever you are running low. When you have E85 near you again, just fill up, and reap the benefits. Pro-tip: if your local E85 station is far from you, buy some fuel jugs and use those to stock up on E85 at home to save some trips.   

Smells: Everyone knows – going catless means smells. Bad smells. However, E85 burns cleaner and the smell is hardly noticeable. This may be useful for some people that are scared of running catless in the city.

MPG and Price: As mentioned before, the fuel system demands more ethanol so it makes sense that MPG will decrease (roughly 18.37% for me). On 91 octane, I averaged 20.2 mpg mixed hwy/city and 16.8 mpg mixed hwy/city on an E70-E85 blend.

Price of E85 is about $2.39/gallon vs $3.79/gallon for Premium 91 at the time of writing. MPG is lower, but I’m actually going more miles per dollar with E85! If you don’t mind making more trips to the gas station, then E85 will technically help your wallet. See below for the cost comparison.

Fuel Tank (16.648 Gallons)MPG$/GallonPrice (Full Tank)Miles (Full Tank)Miles/$1$50 Fuel Spend
91 Octane20.23.7963.1336.295.33266.49

Prior to installing the PROFLEX, we had tossed around the idea of developing an E85 tune. Once I tested the kit, I realized that there was no need for one. The flexibility offered by the kit is unparalleled compared to a flash tune and does not make sense from a customer standpoint to restrict yourself with an E85 tune when this alternative is available. If you are looking to go E85, we would really advise customers to use the money towards purchasing the AFD PROFLEX Commander Flex Fuel Kit instead.

The guys at Advanced Fuel Dynamics are truly knowledgeable about the fuel industry and are very helpful. If you are interested in this product and have questions about it, I’d recommend contacting them directly. Don’t forget to mention this review too! For more information visit Advanced Fuel Dynamic’s product page: PROFLEX Commander for BMW E46 M3 and their FAQ Guide

Coilover Brand Guide

Ultimate Coilover Suspension Company Ranking & Guide

The chart below is our initial attempt for ranking manufacturers and tier levels here is decided on estimated performance, race team usage, prestige and company’s race history (past and present). Price is not factored into this ranking chart. We simply do not have the resources to test out performance of all the suspension companies ourselves, so we base off race results in professional racing or HPDE lap times. We have searched across the internet for a ranking guide for suspensions and we could not find anything. This guide is meant to be used as advice when selecting your next track suspension supplier and is not car model specific.

We categorized suspension manufacturers into 4 tiers below ranked based solely off their top of the line professional race level suspension offerings and the results they achieved with it. Tier 1 companies produces some of the highest race grade quality suspension kits for their customers with no expenses spared. The level of performance required from their clientele is crucial. The race success of these tier 1 offerings is ultimately decided through their support and configuration teams as they all produce quality racing suspensions.

As a reminder, driver mod is crucial to stretching full performance potentials out of these suspensions. It is possible for a better driver with tier 4 suspension to out lap a novice driver with tier 1 suspension. It is also possible for a lower tier suspension with better setup to perform better than an incorrectly setup high tier suspension - but we're not comparing products in this ranking. The differences between ranks are relatively small within the same tier.

This will be an ongoing project and updated ranking will soon be crowd-source updated to reflect real life results from the motor sport community. There is no way everyone will agree with a set ranking of brands. This is our best attempt to objectively rank in numerical order considering the brands prestige, actual race results and history - not necessarily by the specific products they make. Once we have our database ready, the rankings will be changed overtime with new lap time additions. 

What do you think? Drop us a comment below on your thoughts if you agree or if you think a ranking incorrect please show us examples why it should be changed.

Suspension Manufacturer Rankings as of 4/19/2018

Estimated RankTierCompanyHeadquartersApplication
11MultimaticCanadaF1, Cart, Champ Car, F2000, DTM, Indy Lights, GT500, MX-5 Cup, 24 Lemans, OEM Suspension Supplier
21ÖhlinsSwedenF1, F3, MotoGP, World Endurance,WRC, Cart, Lemans, WTCC, VLN, Spa 24H, OEM Suspension on Supplier
31PenskeUSAIndy Car, F1, F3 NASCAR, Sportscar Series, OEM Suspension Supplier
41ZF SachsGermanyWRC, WTC, DTM, Le Mans, F1, F3, OEM Suspension Supplier
51JRZNetherlandsF3, FIA GT, DTM, GTS3, NASA, SCCA
61MOTONNetherlandsDTM, World GT, Trans-AM, ALMS, GTS3, NASA, SCCA
71MCSUSAWorld GT, WTC, World Sportscar, FIA Touring, GTS3, NASA, SCCA
81ASTNetherlandsGrand-AM Challenge, GTS3, NASA, SCCA, ETCC, WTCC, 24H Dubai, BritCar, LeMan, VLN
91KoniNetherlandsF1, GTS3, NASA, SCCA, WRC, Indy Car, GT, Champ Car, IRL, Touring, Drag, NASCAR
101NitronUKMotoGP, Dakar Rally, Formula Drift, New Zealand Superbike Championship, Sports Cars, GT Racing, WTCC
111KW SuspensionsGermanyADAC GT Masters, FIA GT1, GT Open, WTCC, Global Time Attack, Touring Car, KW berg Cup (Hill Club) Group H, King of Europe Drift, VLN, ADAC ProCar, 24H Nurburgring, GT Asia GTS3, NASA, SCCA, ADAC Chevrolet Cup, Audi DTCC, V8 SuperTourer, Cold Cup, Superstar Italy, European Truck Racing, Deutche Rally Meisterschaft, Mini Challenge, Popular with HPDE
122BilsteinGermanyMonte Carlo Rally, 24H, F1, OEM Suspension Supplier, GTS3, NASA, SCCA, Endurance Racing, Popular with HPDE
132EibachUSALemans, NASCAR, WRC, CART, Indycar, Global Time Attack, Popular with HPDE
142HKSJapanSuperGT, Global Time Attack, Popular with HPDE, F3, Drag Racing, GTCC, D1 GP, SuperBikes
152TEINJapanGlobal Time Attack, SuperGT, Popular with HPDE
162TC KlineUSAGTS3, NASA, SCCA, Popular with HPDE
172H&RGermanyNASA, SCCA, Popular with HPDE, OEM Supplier
182Feal SuspensionUSAGlobal Time Attack, Formula Drift, Popular with HPDE
192Fortune AutoUSAGlobal Time Attack, Formula Drift, Popular with HPDE
202BC RacingUSAGlobal Time Attack, Formula Drift, Popular with HPDE
212Ground ControlUSAGlobal Time Attack, Spec E30,
Formula Drift, Popular with HPDE
222Cusco Japan Global Time Attack, Formula Drift, Popular with HPDE
232ST SuspensionGermanySubsidiary of KW, Popular with HPDE
243Skunk2USAWorld Challenge, NHRA Finals, NOPI, Battle of Imports, Grand-Am Sports SCC ST, Popular with HPDE
253K-SportTaiwanHonda Challenge, NASA, Popular with HPDE
263Status Gruppe USAPopular with BMW HPDE
273ISC AustraliaPopular with HPDE
283D2USAPopular with HPDE
293HSDUSAPopular with HPDE
303VogtlandGermanyOEM Spring Supplier
313YellowSpeed RacingTaiwanPopular with HPDE
323XYZTaiwanPopular with HPDE
333TanabeUSAPopular with HPDE
343FKGermanyPopular with Stance
353GodSpeedUSAPopular with HPDE
363Megan RacingTaiwanPopular with Stance
374Street EdgeUSAPopular with Stance
384JOMSGermanyPopular with Stance
394RacelandsUSAPopular with Stance
404RokkorUSAPopular with Stance

E46 M3 E85 - Proflex Commander

Upcoming B-Spec Tune Features - 2/27/2018

We are excited to announce new features coming soon for the B-Spec Tune.

As always, updates and new feature requests are free to existing B-Spec Tune owners.

  • MK20 Performance Traction Control (2001-2002 only): For those with the older MK20 units, we are testing out a performance calibration tune for the MK20 DSC unit. You may notice that the MK20 DSC kicks in a lot harder and more frequent than the later MK60 (2003-2006). The later MK60 has the option of M-Track Mode, however MK20 unit does not have this feature. This feature should help with Launch Control with MK20 Performance Traction Control and making the MK20 less sensitive with aggressive wheel/suspension setups for track days while still keeping DSC on.
  • Ignition Tuning: We are testing out ignition based rev limiter cutoff to aid with no lift shifting. Stock is a 2 stage rev limiter cutoff with fuel and ignition based. Prevents the harsh fuel cutoff at redline.
  • Full Idle Remap (catless Only): We are testing out a cold start remap program that in conjunction with the SAP program disable should make your neighbors a lot happier with those that are running catless. Idle rpm will now be based off of engine temperature sensor instead of catalytic converter sensor temperatures. In essence, idle will try to protect the motor instead of protecting the catalytic converters. We are also researching cold start remap scaling to solve the issue of the standard idle scaling being still too noisy.
  • Lower and Raise Idle: We are testing out the capabilities to raise idle that could help with those who have solid motor mounts and experience NVH.
  • Higher Redline Rev Limiter:  We can now raise the rev limiter to 8,200 RPM while maintaining a flat power-band at that rpm. This will be considered aggressive.
  • Flex Fuel Kit: We are testing out the compatibility of E85 flex fuel kits being used with our B-Spec Tune.


  • Launch Control RPM Limiter (6MT only)
  • Ability to raised standing Idle RPM for NVH or E85 (6MT+SMG)
  • Raised Redline to 8,200 RPM

In Beta Testing:

  • E85 Flex Fuel Kit compatibility with tune (Dyno Scheduled 3/17/18)
  • Flat Foot Shifting (6MT+SMG)
    • Ignition Based Cutoff (Allows for Flat Foot Shifting)
    • Ignition/ 2 Stage Fuel Cutoff (Default)
  • B-Spec Tune Performance Traction Control for MK20 Only - (2001-2002.5)
    • DSC Applied Torque Reduction
    • Revised Initial Torque Intervention Value
    • MK20 DSC Unit E46 M3

In Research & Development:

  • Idle Remap (Cold Start Remap)
    • Quieter Idle Scaling (based off Temperature).

B-Spec Tune Dyno - E46 M3

B-Spec Tune Dyno Results

The long-awaited B-Spec Tune dyno results are now here! We apologize that it took so long, but we wanted to make sure our baseline and B-Spec Tune dyno were as accurate as possible under consistent and unbiased conditions. We appreciate your patience and would like to use this opportunity to provide an extensive explanation of the tune and differences between dynos.

Buildjournal’s Tuning Philosophy

Personally, we’ve (Andrew and I) been running our tunes for 5+ years now with a handful of track days and over 80k miles of combined daily driving with zero tune-related issues. Some of you may know that I started tuning with a few of the members from the M3Forum Tuning & Coding section as a small project, but it grew in popularity. Since then we’ve partnered up with Martyn from ECUWorx to develop some features into his program such as our Exhaust Backfire Tune. Today, we are providing our own off-the-shelf (OTS) tune for the E46 M3.

Buildjournal’s B-Spec Tune is most known for the additional gains in the mid-range of the powerband compared to the stock tune. Our philosophy with the B-Spec Tune to bring a safe, reliable tune to the market that expands on the ultimate driving experience that the E46 M3 already provides. The goal of the B-Spec Tune is to improve driveability and performance – not maximum power.

The Vehicle

B-Spec Tune Dyno - E46 M3

Andrew’s car, the white 2003 BMW E46 M3 6MT, was the test vehicle for both baseline and B-Spec Tune dyno runs. It has over 170K miles and is a testament to the importance of being diligent with vehicle maintenance. On the stock run, it put down a respectable 285 whp and 245 wtq – very reasonable with stock headers, factory stock tune, aftermarket exhaust + resonator, and (crappy) California 91 octane. For the tuned run, Andrew had Evosport headers installed by our friends, Casey and Daniel, at Racewerkz Engineering in Burbank, CA. As you may know, the gains from the B-Spec Tune are maximized when combined with aftermarket headers. The stock catalytic converters is a definite bottleneck in which we see subdued gains compared paired with headers. This is especially the case with naturally aspirated cars especially after opening up throttle plates to full open. Most tuners for the E46 M3 would agree that the stock header design is simply too restrictive and prevents the car from taking full advantage of a tune at the higher end of the power band. That being said, a flash tune on a stock header system still yields some power gains mostly in the mid range.


  • Factory stock tune
  • Macht Schnell Elbow
  • Rogue Engineering El Diablo Exhaust + one (1) AR20 Resonator
  • 91 octane (CA)
  • ~172k miles


  • B-Spec Tune
  • Macht Schnell Elbow
  • Rogue Engineering El Diablo Exhaust + one (1) AR20 Resonator
  • Evosport Headers
  • 91 octane (CA)
  • ~173k miles

Dyno Facility & Conditions

The facility we chose to do our B-Spec Tune dyno testing was at European Auto Source, a very well respected and reputable BMW shop in Orange County, Southern California. Steve at EAS was our dyno operator for all runs to ensure consistency. The dyno at EAS is a Dynojet 224xLC. For consistency purposes – we tried our best to do these runs under the same environmental conditions. Despite California’s recent climate swings, we were able to manage scheduling both runs with an ambient temperature of about 80°F.

How to Read A Dyno

A dynamometer, or “dyno” for short, is a device for measuring force, moment of force (torque), or power. In this case – we did two dyno runs: baseline and tuned. The difference between these two runs show the gains that the tune and headers provides. Please keep in mind that not all dynos read the same – dyno model, ambient temperature, elevation, humidity, and many other factors play a role in a dyno’s reading.

Usually, the first numbers you will see on a dyno graph are the “peak numbers” or the “max hp/tq”. While most will initially look for peak-to-peak gains – this is not what we are focused on. To measure the true performance gains, the important numbers to examine are the deltas (Δ), or actual changes/differences throughout the powerbands of the stock and B-Spec Tune dyno runs.

B-Spec Tune Dyno Results

Buildjournal B-Spec Tune for E46 M3

Buildjournal B-Spec Tune Dyno Results

StockB-Spec TunePeak-to-Peak Net GainMax ΔAVG Δ (5.3K-7.9K RPM)
Horsepower285.79 whp312.04 whp26.21 whp41.79 whp24.68 whp
Torque245.37 wtq248.08 wtq2.71 wtq27.60 wtq18.95 wtq
This chart shows the difference between a stock tune and the B-Spec tune while displaying peak-to-peak and change in delta.

You might be wondering – why is the torque gain so low? Although it is fun to compare max hp and torque, we often forget about the importance of a usable powerband. Comparing peak-to-peak gains do not truly measure the performance a tune adds. As mentioned before, what we need to focus on is the delta between the curves. For a performance tune, you want to have the most delta over certain areas of the powerband and extend that delta as much as possible. Some tunes will try to go for the max horsepower or max torque but sacrifice the powerband to do so. With this in mind – we can move on to analyzing the data.

Low End Power

You can see that at the lower RPMs there is not much difference in the power and torque, this is deliberate as we feel that everyday driving should be kept to OEM feel. We do not modify many parameters in this section of the powerband as there is not much to improve on in our opinion.  That being said, we may revisit this area to see if we can improve this area in the future with updated versions (v2).

One important thing that you may notice that there is one slight fluctuation in power between 3.7k to 4.5k RPM. This is due the fact that Andrew’s headers is missing one bolt which created an exhaust leak. Unfortunately, header fitment was not ideal during installation, but we did not have time to fix the issue prior to the scheduled B-Spec Tune dyno session. The O2 bung covered up the header bolt flange, preventing the bolt from securing the header to the section 1. As you can see, there is no dip in the stock run since the stock headers did not have this problem. However, once RPMs went up, it seemed to have sealed up the leak and performed normally.

Mid to Upper Range Power

The mid-to-upper range is where we can see the significant differences between the stock tune and our B-Spec Tune over the entire powerband. This range of RPM is where track cars live and depend on. Notice that the stock tune falls flat at about 4.7K RPM – the range of RPM when you begin to feel the power tailoring off.  This is the area where improvement was needed and where we concentrated most of our tuning efforts on.  Through a combination of throttle body openings, vanos, fueling, advancing ignition timing, calibrating the knock sensors and more, we were able to maximize these gains in this section of the powerband. Starting at about 5.5k RPMs, you can see the noticeable height difference between the two lines, and in power.

Looking closely,  you will also see that the stock curve ends at 8,000 RPM while the B-Spec Tune curves continues to 8,100 RPM. We raised the rev limiter from the stock 8,000 RPM to 8,100 RPM on B-Spec Tune and accounted for the additional raised RPM. Many tunes simply raise the redline but do not tune for the additional power. You can see that the B-Spec Tune continues to make power even past the stock 8,000 redline with a peak value of 312 whp. If the raised rev limiter is not accounted for in tuning, the car attempts to guess what the missing values should be through interpolation.

Another thing to notice in the stock run are the rough lines near the 7.5K RPM range – this is because the DME pulls some timing in order to avoid knock. The factory knock sensors are overly conservative so we loosened up the knock sensitivity to avoid pulling timing. You can see that this the roughness in the lines were smoothed out in the tuned run.


To put it all together, you’re looking at an average delta/gain of 24.68 whp and 18.95 wtq across the powerband. We draw attention to the average numbers because looking at just the min and max values can be misleading – you’re not just getting a 2wtq or 41whp gain, but rather a distributed power gain in the mid and upper rpm range. Additional gains may be seen in areas with higher octane fuel. Take these numbers how you may, but these are the real power gains you can use, feel, and show faster lap times with.

At the end of the day, we are very pleased with our B-Spec Tune dyno results (despite horrible CA gas) and proud to be able to offer a reliable yet affordable tune to the rest of the community. Again, our goal here is not to make max horsepower and torque, but to improve the overall driving experience of the renowned E46 M3.

If you are interested in purchasing our B-Spec Tune you can purchase it from our Tuning Labs online store.

Future Plans

Going forward, we expect to make some improvements to our tune as we continue to test and make adjustments to the tune as necessary. We are pleased to announce that Buildjournal will be providing free file updates for existing and future customers, both remotely and locally. New customers will automatically receive the most updated version of the tune unless otherwise specified. That being said, we will have an update to release in the near future – existing customers will receive an email from us so look out for it! Unfortunately this means we will be raising the price for the B-Spec Tune to $279 starting November 28, 2017 after Cyber Monday.

Lastly, we would like to thank all of our followers, customers, partners and friends for all the support we have received so far and in the future. Many of you may not know, but we are just a few BMW enthusiasts with full-time jobs. Buildjournal started off as this car’s “build journal” but has come to grow as a platform to share information and become a resource for all things E46 M3 related. We are always looking for new ideas for to create more content and guides, so please feel free to email us with suggestions on what articles you would like to see.

Thank you,
Buildjournal Team

Fine Tune Suspension And Shocks Guide and How To

Here is a decision chart that will help you fine tune suspension setups. We avoid spring rates because this is usually dependent on the valving on your suspension. We assume you aren't super lowered and riding on bump stops. You must maintain correct ride height designed for your suspension system to maintain optimal ride geometry.

Step 1 - Fine Tune Suspension with Rebound Tuning:

  • First you will have to open all valves open to softest setting and then begin your testing.
SymptomFront Rebound Rear Rebound
Understeer at turn-inSoften -
Oversteer at turn-in-Soften
Understeer at exitStiffen-
Oversteer at exitStiffen-

Step 2 - Tire Pressure Tuning:

  • 30-33 PSI for track days. Monitor the PSI as they start to rise from the heat. Adjust accordingly
  • 36-38 PSI for normal driving to conserve tire wear.
SymptomFront Tire PressureRear Tire Pressure
Inner Wear OnlyDecreaseDecrease
Overcooked TiresIncreaseIncrease

Step 3 - Camber Tuning:

SymptomFront CamberRear Camber
Understeer at turn-inIncrease-
Oversteer at turn-inDecreaseIncrease
Understeer at exitIncrease-
Oversteer at exitDecreaseIncrease
Rotate carIncreaseSmall Increase

Step 4 - Swaybar Tuning:

SymptomFront SwayRear Sway
Understeer at turn-inSoften -
Oversteer at turn-inStiffenSoften
Understeer at exitSoftenStiffen
Oversteer at exit-Remove

Step 5 - Compression Tuning:

SymptomFront CompressionRear Compression
Skipping over bumps-Decrease
Power skidding on exit-Increase
Porpoise during brakingIncrease-

Step 6 - Bushing Tuning:

  • Spherical/Solid Bushings will articulate better under bind than Poly.
  • Sway links must be installed pre-loaded, meaning weight of the car on the front suspension. Both sway links should bolt into the sway bar without any force. Otherwise, you will encounter a steering wheel that is easier to turn in one direction than the other since one side will be preloaded incorrectly. If you lower your car you will need adjustable sway links to achieve this optimal pre-load neutrality.
  • We recommend spherical Rear Trailing Arm Bushing due to articulation issues with Poly bushings.
  • We recommend spherical or delrin Front Control Arm Bushings.
  • We recommend matching differential, engine, transmission bushings.
  • We recommend solid subframe bushings.
  • We recommend spherical RSM due to articulation issues with Poly bushings.
  • We recommend spherical lower control arms due to articulation issues with Poly bushings.

Check out our Alignment Specs Guide for your E46 M3 for additional information on suspension setups for track, daily and auto cross. Do you have any  suggestions or feedback? Comment below!