E46 M3 ARH Headers Dyno

ARH E46 M3 Headers Dyno Results and Review

E46 M3 Headers

One of the best mods for the E46 M3 S54 engine are headers and it’s hard to argue it. Not only does it bring out an aggressive tone in the sound department, but it also has one of the best horsepower per dollar figures. I put together an E46 M3 Header Guide article a few years back that compiles some of the more popular header options in the market and I’ve always been curious about power results among the brands. Does it really make a difference? Luckily, I have lots of data of my runs on the same dyno at European Auto Source so whatever I test, I’ll have data to compare against a lot of different setups. And guess what? Recently I just got some ARH E46 M3 headers.

Do stepped headers make more power? Does the Supersprint enlarged diameter really produce the most horsepower? There’s a header not on that list because at the time I wrote it, the product didn’t exist. Welcome the American Racing Headers (ARH), the first 6 into 1 mass produced header, to the picture.

ARH Background

Who or what is American Racing Headers? They’re an American brand (you guessed right) that takes a lot of pride in making high performance, quality exhaust systems right here in the USA – 100% of it. They focus mostly on domestic vehicles, but offer a small line of products for foreign OEM’s like Lexus and BMW. Out of nowhere, they started producing special ARH E46 M3 headers which is 6 into 1 long tube header design for the S54. It consists of six individual 1.75″ primaries mating to one 3.5″ section 1 all made in T304 stainless steel with .049 wall. What does that do? The idea is that unlike the traditional 2-piece header, a 6 into 1 with their “patented rotational firing” design will optimize airflow (even more than the traditional headers) to produce significant power on the S54.

Oh yeah and also, sound! The design of the 6 into 1 should alter the sound ever so slightly, but in a way that it replicates the sound of a V8. We’ve all seen that mysterious video uploaded on YouTube in 2007 titled “Custom M3 Headers” right? I think it’s still a mystery to what exhaust setup it is, but apparently it is a 6 into 1 like the ARH.

Horsepower Claims

ARH E46 M3 Headers Test Results

Okay let’s move onto some numbers. American Racing Headers conducted their own tests comparing a stock E46 M3 S54, traditional header setup and ARH header setup. Both header setups include an intake and tune. They published the following results:

  • 65 whp gain vs stock
  • 15 whp gain vs 'traditional' header
  • Dyno graph shows linear horsepower and torque gains without any significant dips, especially in the low end RPM range

So when you put the data in a table, it looks something like this below. Delta (Δ) is comparing against stock run file.

Traditional Header320.0050.00246.60N/A
ARH Header335.3065.30248.40N/A

Community Results

I know going into this ARH setup, I knew I was going to most likely see a dip in torque – especially the low end of the RPM range. I knew this because I talked to 2 other owners and did a bunch of digging to set expectations before I pulled the trigger on the ARH. All the users I talked to and all the research I found led to strong signs of torque loss, but I still pulled through because…well I’ll tell you why exactly at the bottom of the read.

ARH E46 M3 Headers Dyno Results

Tuned ARH Results

Onto my own results. I’m running the ARH headers, Bimmerworld ‘street/track’ section 2 mated to a Bimmerworld Race 3.5″ section 3. Supporting engine mods include a Turner Motorsport CSL Airbox and Kassel Performance MAP sensor all controlled by the MSS54HP ECU with a HTE custom dyno tune. Unfortunately no off-the-shelf tune will work with this setup and Hassan has a lot of experience tuning these headers so I chose him to tune this beast. Results below:

  • Red line = baseline run (no tune) on 91 octane
  • Blue line = tuned on 91 octane
  • Green line = tuned on E30 ethanol blend (APE Flex Fuel kit)


  • 64.31 whp / 15.17 wtq against stock running 91 octane
  • 68.25 whp / 17.66 wtq against stock running E30 blend

So in terms of max power, it did great! It was actually on par with the ARH claim of 65 whp over stock as I made 64 whp over stock on 91 octane. I also made more than my previous Evosport ‘traditional’ header setup so all good right? Can’t answer that yet until we look a little further. Max horsepower is just a vanity number. What you really need to see is the dyno graph and how much of that power is sustained throughout the RPM range.

E46 M3 ARH Headers Dyno

Here are the max numbers in a table view. I also added in my stock tune run file with only exhaust and intake. No headers. Delta (Δ) is comparing against stock run file.

ARH Baseline Run (91 octane)328.6242.25244.34-1.09
ARH Tuned Run (91 octane)350.6864.31260.6015.17
ARH Tuned Run (E30 ethanol)354.6268.25263.0917.66

Tuned ARH vs Evosport 'Traditional' Header Results

This section of the article is now supportive of what the community claims have been: torque loss. I overlaid my previous setup with Evosport ‘traditional’ headers and E30 ethanol. All the others supporting mods are the same e.g. CSL airbox, Bimmerworld race exhaust, E30 ethanol, etc.

  • Red line = American Racing headers
  • Blue line = Evosport ‘traditional’ headers


  • At 4k RPM we are seeing a ~34 wtq loss and ~26 whp loss with ARH
  • We are also seeing a significant drop in torque from 3.2k-5k RPMs with ARH
  • After 6.2k RPM we see a steady 1-6 whp gain and 1-4 wtq gain with ARH
  • 11.72 whp more than Evosport setup (ARH claim was 15 whp)

E46 M3 ARH vs Evosport Headers Dyno

Here are the max numbers in a table view. I also added in my stock tune run file with only exhaust and intake. No headers. Delta (Δ) is comparing against stock run file.

ARH Headers (E30 ethanol)354.6268.25263.0917.66
Evosport Headers (E30 ethanol)342.9056.53264.8819.45

⚠️ Evosport run result is running OEM CSL tune from MSS54HP and the limiter has a hard cut at 8k RPM. A quick Excel predictive formula shows max whp at 344 whp and 221 wtq at 8.2k RPM. Both are less than the ARH results at 8.2k RPM.

You Said Torque Loss Doesn't Matter, Why?

The loss in torque isn’t a major concern for me because this is a track-only vehicle where it lives in the 5k+ RPM range on track. This is my use case. For yours, it might be different. If you’re just mostly street driving then you’ll definitely feel a difference in power down low if you’re coming from a traditional style header setup.

So back to my track use-case. According to the dyno results, I’ll see significant torque loss if I am below 5k RPM and even if I do dip down I don’t believe it will have significant impact on my lap times. For the areas of the track where I am dipping down to the low RPM range, I can also try shifting one gear higher to keep the car in higher power range. Also worth to note, I am running shorter 3.91 gears so naturally the car wants to be in a higher RPM range which helps.

I just recently took this ARH E46 M3 headers setup to the track to see real world results and the data shows I am mostly in the 5k+ RPM range. The car pulls hard up top and I do think it’s faster than the previous traditional setup. Sacrifice low end torque, that I’m rarely in, for high end horsepower. Even when driving mindlessly around the track there wasn’t a section where I felt down on torque. Actually didn’t come across my mind at all on track even during the 2 slowest parts of the track where I leave it in a lower gear normally. This thing pulls hard all the way to redline.

Overall Takeaways

At first when I saw the dyno results I had second thoughts about sending it back to EAS and telling them to put my old headers back on. But I had to give it a shot on track. Yes, the torque just disappears down low. Yes, even with a tune the low end torque is unrecoverable. However, after actually driving it on track I am very happy and will not go back. This ARH is here to stay.

Lastly, another reason why I am keeping it. The sound! I think it sounds so much better. I mean, part of modifying is not only just to go faster but a balance of form and function. You’re not going to get this type of sound with any other traditional header so that alone makes a car so much more unique. Take a listen for yourself below and if you have these headers, please share a link down below in the comments so I can hear other setups!


  • Lots of horsepower potential after 5k+ RPM, more than traditional style headers
  • Unique exhaust note throughout the entire RPM range
  • Mates to OEM style section 2 for bolt-on connection
  • Built with high quality T304 SS


  • Loss of torque below 5k RPM
  • Expensive
  • Tight clearance to install, may require hoisting engine in the air
  • Requires custom tune to restore as much torque as possible

E92 M3 ARC-8

Ultimate BMW E90 E92 E93 M3 Maintenance Guide

E90 E92 E93 M3: What you need to know

The S65 V8 power unit found in the E9X M3 chassis is the successor to the almighty inline six S54 found in the previous generation E46 M3 – and it’s a lot more powerful. The naturally aspirated engine is also the latest and probably the last of the NA engines in BMW’s M heritage as they moved on to forced induction-based power units. If you are a owner, you have one of the best sounding BMW M3’s ever built and with proper maintenance, the S65 isn’t all that bad to maintain.

We did a complete maintenance guide for the E46 M3 a while ago and we’re going to do the same guide for the E9X M3. If you have an E46 M3, you might want to bookmark this page: E46 M3 Ultimate Maintenance Guide and Schedule

Disclosure: Some of the links in this article are affiliate links, meaning, at no additional cost to you, we will earn a commission if you click through and make a purchase. We thank you for your support.

Reset On-Board Computer

The on-board computer controls and displays several service features for your E90 E92 E92 M3. It is a secondary display that cross-functions with the DME to read out values but also can be used to change some settings such as resetting service intervals. There’s even a “hidden menu” that you can access! The mileage logged on the OBC determines when to flash a service warning at you via iDrive or gauge cluster lights.

Follow the procedure below to reset your service intervals on the OBC:

  1. Insert key fob or use Comfort Access then press "Start" once - do not start engine
  2. Depress brake pedal and hold the odometer reset button on the bottom left of your gauge cluster until the yellow triangle appears on the mini display
  3. Use the scroll wheel on the left hand turn stalk and select an icon to reset e.g. oil icon for oil service internal reset
  4. Press the "BC" button on the same turn signal stalk
  5. Click "BC" to choose Reset
  6. Press and hold "BC" for a few seconds
E92 M3 GTS Interior

E90 E92 E93 Basic Maintenance Schedule

The factory recommended service interval from BMW is listed below, however it is very important to note the factory oil change interval of 15,000 is considered pretty long and most owners change their oil a lot sooner. We’ll detail more below why it’s important to change the oil sooner, but long story short, the S65 has the same rod bearing tolerance and wear issues as the S54 so oil degradation can cause premature failure to your rod bearings especially if not driven after proper warm up procedures.

We recommend changing the oil every 7,500 miles or even 5,000 miles as your mileage gets higher towards the rod bearing service interval. So with that said, you can follow your own maintenance procedures for the engine oil and filter. Keep in mind, the harder to drive, the faster you should replace. Especially if your engine sees a lot of track time.

MilesEngine Oil & FilterDiff FluidTrans Fluid (MT)MicrofilterSpark PlugCoil PacksIntake FilterBrake FluidPower Steering FluidO2 SensorVehicle Check

Recommended Parts for Regular Maintenance

Oil Change Kit

Priority: ❗❗❗❗❗


I use the LIQUI MOLY Synthoil Race Tech GT1 10W-60 on both my S65 E92 M3 and S54 E46 M3. You’re gonna hear a lot of mixed reviews about this product, but I’ll tell you I have 190k miles on my E46 M3 with a lot of hard track miles and my engine is still running very strong.

Oil Additives

Priority: ❗❗❕❕❕


To be used occasionally during oil changes, CERATEC is a friction modifier which helps our rod bearings stay lubricated. Especially important because the S65 does have rod bearing issues similar tot he S54 on the E46 M3. Before your next oil change, pour in the ENGINE FLUSH, idle and drain the oil, do the oil change, then finally top off the engine with some CERATEC. Check out our review we did with the LIQUI MOLY MoS2 friction modifier.

Spark Plugs

Priority: ❗❗❗❕❕


This is the spark plug I use on my S65 E92 M3 even with the ESS Tuning G1 supercharger kit. They are a reputable company and this is a direct replacement for the Bosch spark plugs (BMW P/N 12120032273) that come from factory. They come pre-gapped and allows you to retain the factory knock sensor system which is very important.

Ignition Coil Packs

Priority: ❗❗❗❕❕


Bad coil packs will cause cylinder misfire followed by CEL codes. Why? Coil packs are responsible for delivering power to ignite your spark plugs. These are recommended to replace around 60k miles of use. If you’re getting codes for misfire, before you automatically go to replace your spark plugs, try moving around the coil packs from the problem bank to another to see if the code follows. If it does, you know it’s the coil packs.

Differential Oil

Priority: ❗❗❕❕❕


Same as the Castrol “SAF-XJ” differential fluid and includes a friction modifier. Name of the product was rebranded to Syntrax. You’re probably asking me, don’t I need the FM booster? Let me clear this up as brief as possible. The “SAF-XJ+FM” has been a subject brought up all over the forums and internet because of users complaining about grinding sounds on full lock so BMW made the SAF-XJ+FM which just has more of the same friction modifier that the old one had. This pleases 90% of the street driven customers, however, this also causes problems on the track because too much friction modifier or “FM” can cause LSD to slip which is what a performance LSD should not be doing. TLDR: try the Syntrax, if you really don’t like grinding noises add a bit of off-the-shelf friction modifier. If you track, Syntrax will be just fine.

Transmission Fluid

Priority: ❗❗❕❕❕


So far I’ve only done one transmission fluid change on the E92 M3 6 speed and I used the Red Line MT-90 which is a little thicker than the Red Line MTL but so far no issues even at cold startups. Every gear shifts super crisp. I’m very happy and haven’t thought about replacing the fluid.

Recommended Parts for Mandatory Maintenance

Rod Bearing

Priority: ❗❗❗❗❗


You know this was coming. This can not be treated lightly and must be done as a preventative maintenance, not a reactive maintenance, because your engine can detonate. There’s no documented life expectancy from BMW because it highly depends on how you maintain and drive your car, but the community best practice is to shoot for the 80k mile mark. There’s a lot of debate on which type of bearings to get, but if it were me I would get BE simply because it has around .0024″ tolerance which is slightly larger than OEM spec. Is that the root cause of the issue? No one knows. The one thing I can tell you is that oil change and maintenance is the most important part. Which ever bearing you get, they will all wear. Do frequent oil changes, no cold start high revs, and make sure your installer knows how to properly install and torque the rod bolts to spec. Oh yeah, BE also is made with industry standard lead-copper so you can track wear with oil analysis samples.

Throttle Actuators

Priority: ❗❗❗❗❕

VDO Throttle Actuators

Throttle Actuators are responsible for mechanically opening and closing the throttle so if it’s broken, you’re gonna be left stranded and on a flat bed back to a shop. The weak point inside the actuator are 2 things: plastic gears and electronics. The most common are the weak plastic gears which break over time. There are solutions to go with metal gears, however there is still a chance that your electronics are going to fail so it’s always recommended to replace the entire unit – both sides. We recommend the factory-supplier VDO for replacement actuators.

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E90 E92 E93 Windshield Gasket Moulding DIY

Does Your Windshield Trim Moulding Look Like This?

Replace Your Weathered Windshield Trim Moulding

Overtime the rubber material around the windshield begins to dry out and crack. It gets real ugly. Once it gets to my level, pictures below, it’s also harder to remove because the strip chunks off in pieces instead of just removing it as one long piece. So before it get’s really bad, I highly recommend you replace the windshield gasket as soon as it starts to show signs of dryness. You can check visually or physically. Easiest way is to just touch the moulding out lip and see if it’s brittle. Be careful when testing because it may just chunk off.

In my case, I’m replacing the windshield moulding on my E92 M3 Coupe. Part numbers are different for different body styles so make sure you get the right part number which I will also provide down below.

For E92 Coupe

For E93 Vert

Tools Required

  • Goo Gone
  • Rubbing alcohol
  • Plastic scraper
  • Flat head screwdriver or pry tool





Install Directions

1. Lift old windshield moulding by prying up corners. You may need a flathead or pry tool to start the removal. The moulding has a metal u-channel that slots over the windshield.

E90 E92 E93 Windshield Gasket Moulding DIY

My moulding was so bad that it was breaking off in pieces! Super annoying to remove piece by piece, but a little plastic scraper helped speed things up.

E90 E92 E93 Windshield Gasket Moulding DIY

The top portion was a bit tricky to get started. It’s a tighter fit than the sides so I had to use a flat head to pry up the moudling.

E90 E92 E93 Windshield Gasket Moulding DIY

2. Once the old moulding is removed, clean up the body free of dust. Use Goo Gone or adhesive remover to get all the old adhesive off.

E90 E92 E93 Windshield Gasket Moulding DIY

3. Install new windshield moulding trim. DO NOT REMOVE THE DOUBLE ADHESIVE TAPE JUST YET.

E90 E92 E93 Windshield Gasket Moulding DIY

Once the moulding is installed in place, then remove the double sided adhesive by pulling on the yellow tabs.

E90 E92 E93 Windshield Gasket Moulding DIY

The new moulding should also have a u-channel to slot the windshield. Fitment might be tight, but it will go down.

E90 E92 E93 Windshield Gasket Moulding DIY

Now you’re done!

BMW E46 M3 Radiator Duct - Buildjournal

E46 M3 Buildjournal Radiator Duct Install

Is Your E46 M3 Overheating?

The E46 M3 front air intake duct works just fine, but overtime the plastic gets brittle and the bottom portion of the duct tends to bow. This causes air to slip past the oil cooler and radiator limiting the maximum air for cooling. In addition, you do not want air to escape past the cooler/radiator as this will cause unwanted lift. Without getting too technical on aerodynamics, you want to keep faster moving air below the bumper and slower moving air on top.

Our Buildjournal Radiator Duct for the E46 M3 is an all-aluminum piece to avoid any future bowing due to wear and tear. It’s also lightweight at just 3 lbs. The install is also super easy. We’ll show you how to install it.

⚠️ Currently this product has not been tested with aluminum reinforcement front bumper beams found on earlier E46 M3 models.

Parts List

  • (2) End plates
  • (1) Bottom plate
  • (4) M6 Nutserts
  • (4) M6 Hex Head Bolts
  • (4) M6 Button Head Bolts
  • (4) M6 Nylon Nuts

Tools Required

  • 10mm socket/wrench
  • 4mm allen key
  • Nutsert tool
  • 9mm or 23/64" drill bit





Install Directions

1. Remove Bumper

2. Remove bumper reinforcement beam/bar

3. Remove OEM radiator shroud

Note: OEM radiator shroud can be trimmed to keep existing ducts for upper kidney

BMW E46 M3 Radiator Duct - Buildjournal

4. Find the (4) OEM holes on the radiator support bracket and drill using a 9mm or 23/64″ drill bit – there are 2 on each side

BMW E46 M3 Radiator Duct - Buildjournal

5. Install the provided M6 nutserts

BMW E46 M3 Radiator Duct - Buildjournal
BMW E46 M3 Radiator Duct - Buildjournal

6. Install the radiator duct using the supplied (4) M6 hex head bolts

BMW E46 M3 Radiator Duct - Buildjournal

Also watch Ride with Kee‘s step-by-step install video for our Radiator Duct!

Special thanks to Kee and Stefan for putting together this video!

BMW E46 M3 For Sale

E46 M3 For Sale Market Price Tracker

How much are E46 M3's going for?

Are you looking for an E46 M3 for sale? Or are you just curious to see how much your E46 M3 is worth? Even just a few years ago we’d see 100k mile E46 M3’s going for around $15k on the used marketplace and it seems like nowadays those are hard to find. Even 100k+ mile E46 M3’s are going for $20k+. It makes you wonder, are we really going to see an uptrend in market value? We’ve done a little research into the actual sales values of E46 M3’s and put together a visualization of what’s going on in the market for the past few years.

Methodology: We built a database with sales records from multiple resources including eBay, Bring a Trailer, forums, etc. Our database contains sales values from confirmed listings.

  • E46 M3 prices increased in 2020 with a 13.17% change year over year (YoY) in sales value for E46 M3
  • Average mileage for E46 M3 sold in 2020 is 65,591 at a price of $26,885

E46 M3 for Sale (Actual Sales Data)

E46 M3 - Sales by Mileage

E46 M3 - Average Sales Price by Year Sold

We can definitely say there is an uptrend with E46 M3 for sales values. These are completed listings. So all of the incomplete bids, auctions or listings are omitted. Even with mileage going up on these cars sold, the price is still going up. If you have a mint condition, low mileage E46 M3 maybe you should garage it more. For more information on how to take care of your car check out our Ultimate E46 M3 Maintenance Guide.

E46 M3 Power Steering Install DIY - Chase Bays

Chase Bays E46 M3 Power Steering Kit Install DIY

Upgrade your power steering

I got the revised version of the Chase Bays Power Steering Kit for the E46 M3 (S54) because I was tired of my OEM hoses seeping with fluid. I had to replace my power steering expansion hose twice already and my OEM reservoir twice as well because of leaks and cracks. Well, it was leaking somewhere again and most of my hoses were soiled so I decided to get stainless steel lines with AN fittings.

I said revised version because I’ve been talking to Ryan from Chase Bays to improve the power steering kit. They’ve made some changes to the fittings to optimize delivery of the fluid. This includes a check valve on the rack and a smaller AN fitting on the reservoir side to replicate OEM fluid movement. I’ve been testing the changes at the track under hard conditions and I just came back from testing the setup a few days ago and there were no issues. I will continue to test and give feedback to the team at CB if any.

We have been selling Power Steering Kits for numerous chassis and engine types for the last 10 years, in total around 10,000+ kits. This has given us extreme confidence in our products. We are surprised and baffled, pun intended, to learn you were still having issues after our troubleshooting that solves 99% of issues.
Designing products all these years has humbled us. No matter what, there can always be a variable you haven’t seen or considered. BMW is no stranger to this. Once we started our research, we found that BMW made a few technical updates to E46 M3’s specifically. We were able to work around the updated LF30 pump that has the enlarged outlet (higher total output flow than non M3’s) by adding a check valve and restricted banjo bolt on the rack inlet port. Having a customer like Andrew @ Buildjournal who understands automotive troubleshooting is key. We were appreciative of his assistance to work through development to find a repeatable and consistent solution. Now we can proudly offer track-tested reassurance to customers trying to get the most from their M3’s by upgrading their steering system for trouble free competitive use. -Chase

Is there something wrong with OEM? Not really. The OEM unit can last for a long time and it’s not a super common thing for these power steering pumps to fail either. However it is highly likely that your stock reservoir is going to crack sometime. When that happens, you might want to think about replacing the system to not have cracking issues ever again.

Disclosure: Some of the links in this article are affiliate links, meaning, at no additional cost to you, we will earn a commission if you click through and make a purchase. We thank you for your support. 🙏

Chase Bays E46 M3 Power Steering Kit

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Parts List

  • Triple Baffled Power Steering Reservoir w/ Bracket
  • Heatsink Cooler
  • Cooler Brackets
  • -6AN stainless steel high-pressure hose
  • -6AN stainless steel reservoir to cooler hose
  • -6AN stainless steel cooler to rack hose
  • -10AN stainless steel reservoir to pump
  • Various AN fittings

Tools Required

  • 10mm socket
  • 12mm socket
  • Shorty wrenches or AN wrenches
  • Wobbles
  • Extensions
  • Jack + stands
  • 1L ATF fluid
  • Funnel





Chase Bays Power Steering Install

Remove Intake Plenum

1.1 Remove 4 nuts holding front strut bar.

1.2 Remove 4 torx screws holding cabin filter housing, remove filter.

1.3 Remove intake including the nut for the oil dipstick.

1.4 Remove crankcase vent hose.

1.5 Remove vent hose grommet to give some more slack in the line when you take out the airbox.

1.6 Remove the throttle body hose clamps. There’s not much grip and clearance so I had to use angled needle-nose pliers and locking pliers to squeeze the rivets together and with a flat head pry out the clamp simultaneously. Basically in the bottom picture below, I pry the two rivets together to alleviate clamping force and then used a small flat head to pry out the end of the clamp pictured on top.

1.7 Remove the (2) two nuts holding the bottom of the intake box. Detach plug grommet between the two nuts.

1.10 This part is a little tricky (any is the part everyone talks about breaking) so pay attention! Before the airbox comes out, you have to unclick the (small) vent hose below the intake box, but because the clearance is so small you have to wiggle the box out a little to slide your hand in. Be gentle because this part is fragile and if you break this hose, it’s going to be an annoying trip to the dealership.

The best thing to do is slightly pull the airbox halfway out and then unclip the (small) vent hose.

Here is a picture showing the underside of the airbox.

1.8 Unclip the (large) vent hose on the bottom of the intake box. Here is a better view of the (large) lower vent hose and the 2 nuts holding the airbox.

1.9 Unclip the holder for the smaller vent hose on the side of the intake box – the small highlighted tab has to be pressed down and the plastic holder will slide up. (not away from box)

2. Drain Power Steering Fluid

2.1 Locate the power steering hose that runs from the reservoir to the power steering pump.

2.2 Remove the hose OEM hose clamp using a flat head and drain the fluid into a disposable container.

3. Remove OEM Power Steering

3.1 Remove the high pressure power steering hose underneath the car by the front sway bar. The hose is secured to a 10mm hex head bolt holding the bracket in. Remove the entire bracket from the steering rack.

3.2 There are two ends coming from the high pressure hose. One is connected to the steering rack (upper) with a M14 banjo bolt.

3.3 The other is a M16 banjo bolt on the pump.

3.4 Disconnect the two hose from the stock cooling coil. One is coming from steering rack (lower) and the other is coming from the reservoir. Push in the white plastic tab first and then pull down. I decided to entirely remove my cooling coil as it won’t be needed since I have the CB cooler.

3.5 Loosen the 10mm hex bolt on the clamp holding down the reservoir. You can now pull the entire reservoir out from the top.

4. Install Chase Bays Power Steering Kit

4.1 Get familiar with the hose diagram. The install is actually really easy. The only challenge is tightening down the AN fittings because the clearance is not much for large wrenches. Shorty wrenches FTW. Or get proper AN wrenches.

4.2 Install CB cooler using the supplied rubber clamps. The shorter clamp goes on the passenger side of the cooler. I have a ZCP (Yellow Tag) steering rack and it has 2 M6 mounting locations pre-threaded. OEM should as well.

I actually had some new bolts laying around. If you want new bolts, they are M6 10mm bolts.

4.4 Install the cooler hose from the passenger end to the CB reservoir. You can leave the CB reservoir sitting in the clamp, but loose since it’s a bit of a struggle to tighten it down in there.

4.4 Install the other end of the CB cooler hose into the steering rack (lower). Make sure your banjo bolts have crush washers on both sides of the banjo bolt!

4.5 Now install the high pressure line going from the pump to the steering rack (upper). Use the supplied male-male AN fitting on the pump, then fit the female AN. You do not need to use Teflon or sealant for any of the AN fittings.

4.6 Install the other end of the high pressure hose into the steering rack (upper). Again, make sure you have 2 washers sandwiching the banjo bolt. Make sure the hard lines are not touching any of the suspension components.

4.7 Your last hose is the reservoir to pump. The pump end attaches with the supplied hose clamp.

4.8 Tidy up your lines and secure the fittings on the CB reservoir. Now you can tighten the reservoir clamp down using the supplied bracket.

5. Fill Fluid and Test for Leaks

5.1 Follow the directions as stated by Chase Bays to properly bleed the power steering system. You can use any ATF fluid. I used 1L of Pentosin ATF 1.

  1. With the the car jacked up, fill the Chase Bays Reservoir to halfway full.
  2. Turn the wheel back and forth to lock five times with the car off. This will allow some fluid to get into the Rack and Pump while the car is off so the system doesn't start completely dry. Add fluid if needed to keep it at half way full.
  3. With the car still in the air, start it up. Let it idle for 3-5 minutes while checking for leaks at all the connections. If there are no leaks turn the wheel back and forth to lock five times.
  4. Put it on the ground and start it up. Turn the wheel back and forth to lock five times. Now take it for a test drive. Drive around for 15-20 minutes and take note of how it sounds/feels in the beginning compared to the end. We have seen great results from this install process, combined with letting the car sit for an hour after the initial drive.
  5. Check for leaks one last time, if everything is good you're ready to rock!

E46 M3 Splitter Install DIY

Quick-Release Splitter DIY Install Guide - E46 / M3

How To Mount Splitter Using Quick-Release Splitter Brackets

This splitter DIY guide will walk you through the install process using our Buildjournal Quick-Release Splitter Brackets for the E46 / M3. Splitter mounting to your chassis can be difficult, but not anymore. We’ve developed a 100% bolt-on chassis mounted bracket that uses a skeleton frame to support the rear of the splitter, which is new for our latest version enhancement. Quick-release is even quicker now. A huge evolution over our old V1 brackets.

If you have your own rear mounting solution we also offer the front brackets by itself without the skeleton brace. This splitter DIY will cover the installation for the Full Kit with Rear Support.

Buildjournal E46 M3 on APEX ARC-8R Forged

Tools Required

  • 10mm socket
  • 10mm wrench
  • 5/32 hex drive
  • Q-tip
  • Permanent marker
  • Power drill
  • 1/4" drill bit
  • Jack + stands

Splitter & Bracket Installation Instructions

⚠️ Disclaimer: This DIY does require you to lift your car so please use proper tools and follow all safety procedures if you choose to attempt. This guide is for your reference only. We are not liable for any damages or injuries that result from this guide.

1. Install Rear Splitter Bracket

1.1 Jack up the car.

1.2 Remove and discard the OEM plastic undertray.

1.3 Locate the 3 factory holes located on the front reinforcement plate which holds the plastic undertray.

1.4 Using the supplied hardware, mount the rear bracket to the 3 holes on the front reinforcement plate – hex bolt side down. Do not tighten it down just yet. This will help with the splitter alignment in the next steps.

2. Assemble Front Brackets

2.1 Use the picture here to assemble the bracket. Each side of the bracket is made with 3 main parts: main bracket, adjustment plate, splitter feet. It’s important the orientation is set correctly otherwise you will have alignment issues with the skeleton brace and rear bracket. Pictured on left is the left/driver side.

3. Install Front Splitter Bracket

3.1 Remove your front bumper and Kevlar/aluminum bumper beam. If you have the aluminum bar, you need to also remove the bumper shocks. For now, leave the bar and bumper off. Notice how the splitter feet lines up with the rear bracket.

3.2 Use the OEM nuts to hold the front brackets in place, but do not tighten all the way down. This will help with the splitter alignment in the next steps.

4. Align Brackets & Set Height

4.1 Insert the quick-release pin into the feet/adjustment plate and tighten down the thumb screws. This is important for the alignment. Your front brackets, adjustment plates and rear bracket should be loose.

4.2 Temporarily install your bumper back on to set the the splitter height.

4.3 Rest the jack on your splitter and jack up to the desired height. Make sure the frame is in place.

4.4 Once the splitter height is set, carefully remove the bumper.

4.5 Tighten the front brackets and adjustment plate. Your front brackets are now set.

4.6 Secure the frame to the feet with the holes aligned and use a clamp to hold it in place while you adjust the rear bracket.

4.7 Make sure the rear bracket and frame are in contact with each other or else you’ll experience some back and forth deflection. Tighten down the rear bracket. Now your frame should be all set. Test for any play and adjust if necessary.

5. Align Splitter

5.1 With the splitter still in position, mount the bumper back on and visually align the splitter to where you want it to mount.

5.2 Remove bumper once splitter position is set.

5.3 With the feet aligned with the frame holes, mark your drill points on the splitter. I put some ink on a Q-tip and marked the holes straight down using the first and last holes on the feet. Splitter mounting requires a minimum 4 mounting points from the feet to the splitter.

5.5 Drill the marked holes using a 1/4″ bit.

6. Install Splitter

6.1 Use the supplied hardware to mount the splitter through the frame and onto the feet.

6.2 If you are using our Splitter Brace, you can install that during this step. This brace adds support for the front of the splitter for those not wanting to run splitter rods outside on the exterior of the car. It also doubles as a splitter skid plate.

6.3 If you are using our Splitter Rods with Shocks, you can install them now.

6.4 Your install is complete. Check for play and adjust if necessary.

We offer 8" splitter extensions for those that want to extend the rear all the way back to the reinforcement plate. Available on our product page.

Buildjournal Splitter Bracket with Quick-Release

E46 M3

Starting $250

E46 M3 Megane RS Brembo BBK Retrofit Install DIY

E46 M3 Megane RS Trophy-R Brembo BBK Retrofit Install DIY

Upgrade your E46 M3 brakes

We offer the E46 M3 Megane RS Trophy-R BBK retrofit kit as a brake upgrade for your S54. The kit features large pistons, stainless steel lines, custom caliper bracket, brake pad hardware, and all other hardware necessary for the kit install. The kit uses OEM Competition/CSL/ZCP 345×28 rotors. Rotors and pads are not included with this kit, but they are very common.

If you need help selecting brake fluid, please take a look at our Ultimate Brake Fluid Comparison Guide where we have a table sorted by boiling points. The higher the better.

Disclosure: Some of the links in this article are affiliate links, meaning, at no additional cost to you, we will earn a commission if you click through and make a purchase. We thank you for your support. 🙏

Megane RS Trophy-R

For E46 M3

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Parts List

  • (2) Brembo Megane RS Trophy-R Calipers
  • (2) Buildjournal Caliper Adapters + Hardware
  • (2) Porterfield Custom Stainless Steel Brake Lines
  • (2) Brake Pad Hardware
  • (1) Loctite 263 Threadlocker

Supporting Parts List

Tools Required

  • 5mm hex
  • 10mm hex
  • 12mm hex
  • 11m wrench (brake line)
  • 14mm socket
  • 16mm socket
  • 17mm socket
  • 16mm wrench
  • Torque Wrench
  • Angle grinder/Dremel
  • Safety googles
  • Hammer
  • Jack + Stands





BBK Retrofit Install Directions

Disclaimer: This DIY does require you to lift your car so please use proper tools and follow all safety procedures if you choose to attempt. This guide is for your reference only. We are not liable for any damages or injuries that result from this guide.

1. Jack up the fronts and remove your front wheels.

2. Remove OEM calipers

2.1 Remove the brake line rubber grommet and brake line wire sensor. Take note of the factory line/wire routing.

2.2 Remove the two 16mm bolts that attaches the caliper to the spindle.

2.3 Suspend or place the caliper so that there is no tension on the brake line. Do not remove your OEM brake line from the hard line just yet.

3. Remove OEM rotor

3.1 Use a 5mm hex to remove the two caliper retaining bolts. It is highly recommended to use new bolts. They’re super easy to strip and they’re cheap enough. See below for part links.

Tip: It might be easier to remove caliper if you loosen the 5mm hex bolts first before you remove the calipers, step 2.

OEM Rotor Screw – 34111123072

OEM Rotor Screw (Stainless Steel) – ES#2550873

4. Trim OEM heat shield

4.1 Use a dremel or cutter to trim a few inches to make clearance for the caliper bracket and caliper.

5. Install caliper bracket

5.1 Apply a small amount of Loctite to the bottom of the (silver) bolt threads and install the caliper bracket to the knuckle. Make sure to use supplied washer.

5.2 Torque to 50 ft lbs using a 10mm hex.

6. Install new rotor

6.1 It is recommend to clean hub with wire brush before putting the new rotor on.

6.2 Install the two 5mm hex bolts to secure rotor to hub.

7. Install brake line on back of caliper

7.1 Make sure you use two crush washers (supplied) on each end of the banjo fitting. Torque to 15 ft lbs using a 14mm socket.

8. Remove OEM brake line using 11mm wrench

8.1 Get ready to swap brake lines with the new stainless steel fitting. Grab a towel to catch the brake fluid from dripping on the ground. Some very important things to note here:

  • The new stainless steel lines come with an adapter fitting so you must tighten both.
  • Once the new line is installed, make sure the hard line is not touching anything.
  • Lastly make sure you're not sandwiching the OEM brake line holder bracket with the fittings.

Optional: If you want to keep the brake line connection factory-style, you can bore out the factory star pattern slot that holds the OEM brake line. You can then slot the new stainless steel line through the bottom side of the factory bracket and use the OEM metal retainer clip to hold the line in place.

9. Install the two (black) bolts to the caliper and bracket

9.1 Use a little bit of Loctite on the bottom of the threads and torque to 50 ft lbs using a 12mm hex. Make sure to use supplied washer. Caliper bleeder nipples should be facing upwards.

9.2 Install new brake line grommet to factory bracket. Follow same brake line routing as factory.

10. Install brake pads

11. Install brake pad retainer clip and pins

12. You’re done! Repeat for other side and check for immediate brake fluid leaks.

12.1 Now you need to bleed your brake system. Please follow proper procedure to bleed calipers. Zeckhausen Racing has a good brake bleed article.

12.2 Follow brake pad break-in procedure if necessary.

12.3 Monitor your brake system for the next few days and check for any leaks, line contact, etc.

BIMMER CHALLENGE - Streets of Willow

Essential E46 M3 Track Day Mods and Guide for Beginners to Advanced Drivers

Are you taking your E46 M3 to the track more? Well good because it’s a great out of the box platform to take to the track. Even bone stock, it’s a very well balanced car. It doesn’t have a ton of horsepower but the car is very forgiving to drive with just enough oversteer to control. Now when you start upgrading, the E46 M3 becomes incredibly capable of producing very fast lap times. And if you haven’t taken it out on the track or autocross course just yet, you should! I’ll go through my experiences from my first time out to where I’m at now competing in a small time attack series.

Whether you are building a serious E46 M3 track car or first time going out, we’ve compiled a track day guide to get you acclimated to the wonderful sport of Motorsports. Check out below for the list of essential E46 M3 track day mods.

Disclosure: Some of the links in this article are affiliate links, meaning, at no additional cost to you, we will earn a commission if you click through and make a purchase. We thank you for your support. 🙏

First Track Day

1. Maintenance

The first thing for any BMW owner is to make sure the overall health of the vehicle is in good status. And this isn’t just a thing for first timers, but for anyone who is taking their car to the track. We wrote the Ultimate E46 M3 Maintenance Guide which covers the Inspection I and Inspection II protocols. It’s a good starting point to go through this list and make sure all your basic maintenance items are covered. The most important part of track day is safety. All track day organizations have some sort of track day tech inspection sheet which you must fill out and sign in order to participate.

2. Alignment

A good alignment can dramatically change the handling characteristics of your car. We made an E46 M3 Alignment Specs Guide to list setups depending on the driving type e.g. autocross, track, etc. Once you start exploring different tracks you’ll want to change your alignment to dial in for that specific track, but this is a good baseline to start.

3. Tow Hook

It’s pretty much mandatory to run at least one tow hook point on the front or rear and both are highly recommended.

4. Build Track Awareness

The primary goal of your first track day is not to go fast, but to learn how a track day works. You’re going to learn things like spotting the flag towers, memorizing all the different flags, knowing where to enter pits, learning to exit pits, signs for passing other vehicles, learning track lines, learn to hit the apexes, etc.

2-5 Track Days

1. Brake Pads

Now you want to start building confidence mods. Not fast mods. The confidence will make you faster. Brake pads can help you stop when you need to.

2. Stainless Steel Brake Lines

Again, another confidence mod. Stainless steel lines won’t expand as you apply more brake pressure on your pedal. Your stock rubber lines will. SS lines will make the pedal feel more firm and better response.

3. Coilovers

This is a big one. Suspension is very important and changes the entire behavior of your car on-track performance. The more grip you have with the tire and road, the more G’s you can pull. The more G’s you can pull, the better your car will be around corners. This concept is called mechanical grip.

4. Brake Fluid

Brake fluid can boil and add air in your lines. Air is not good because it is compressible meaning if you step on your pedal and pass through air, your pedal will go down, but the pressure won’t be applied to the brakes. We wrote an article on the best racing brake fluids.

5. Tires

Similar to suspension, tires will help increase mechanical grip. Different tires have different compounds. The idea is that the lower the treadwear rating, the sticker it is. Grip vs life is a direct trade off.

6. Wheels

You want the strongest and lightest wheel possible to reduce unsprung weight. Rotating mass requires more momentum to move, meaning there is an exponential effect for every extra pound added on to unsprung weight. Also you might need to get a wider wheel to fit a larger tire for maximum grip.

7. Data Acquisition

If you want to improve as a driver, you need to study your data and results. A proper data acquisition system like the AIM Solo will give you at the minimum – lap time, g-force, MPH. Through graphing and visualizations, you can see where you are fast and where you need to improve.

6-10 Track Days

1. Radiator

You’ve probably done a few super hot days already and realized your cooling isn’t good enough. The OEM radiator has plastic end tanks and are prone to crack. It’s probably a good idea now to replace with an all aluminum tank.

2. Steering Rack

The stock E46 M3 (non ZCP) steering is pretty numb because of the low ratio. You can upgrade your rack with a “yellow tag” E46 ZHP rack found on the 330 and some regular 330’s. The BMW part number is 7852974712. The faster steering ratio feels great on track.

3. Exhaust

Now that you’re becoming familiar with your car, you can start upgrading power. Just be mindful. Driver mod can still shave you more time than what a 5-10 hp increase an exhaust can get you. Learn the car as much as you can and once you feel confident with your driving abilities, get power.

4. Short Shifter

If you’re driving a manual, an upgraded shifter can change your gears faster. Meaning you can increase speed faster resulting in faster lap times. I recommend a good trans mounted shifter like an RTD or CAE.

5. Subframe Bushings

You should know the E46 M3 subframe is prone to cracks. Strengthen up your diff bushings while you take care of the subframe reinforcement by adding in some race poly or solid bushings. Solid bushings will be loud, but removes 99% of the deflection. Race poly is still good if you’re doing street/track duty.

6. Transmission Bushings

Why do you need transmission bushings? The powertrain will see a lot of force on track causing movement which can affect your shifting especially for manual cars. Ever try shifting in high G corners and the selector rod just doesn’t seem to want to get in to gear? You may have bad transmission bushings.

7. Differential Bushings

Soft OEM bushings are designed for comfort, but it’s not the best for track performance. If you get rid of deflection, you can put more of the power and grip down to the ground. Same logic goes for all your bushings.

8. Intake

Probably one of the easiest way to increase horsepower to your car. More air in the engine means more power. Although there is a lot of debate about aftermarket performance intakes, the right one will produce more power over OEM. We recommend Turner CSL or Eventuri.

9. Tune

In addition to an intake, a tune will maximize performance by re-calibrating engine parameters to produce more horsepower. We can help you tune your S54 with our B-Spec Tune.

11-15 Track Days

1. Front Control Arm Bushings (FCAB)

OEM FCABs provide comfort for driving, but allows a lot of deflection in the front wheels. Upgrading to a harder bushing allows for increased “steering precision, turn-in response, and direct braking feedback” which makes the car feel very direct on track. We recommend the Turner Monoball FCAB for heavy track use and there is essentially no increased noise, vibration or harshness (NVH).

2. Rear Trail Arm Bushings (RTAB)

While you’re doing the FCAB upgrade, match the bushings with a similar rear trail arm bushings. RTABs can help with “maintaining alignment settings and minimizing wheel hop” by removing deflection. On RWD platforms, it’s important to get the power down to the ground by getting all the grip you can.

3. Roll Cage

You’re getting faster now and safety is still #1. At the minimum, you want to add in a half cage roll bar to protect incase of a roll over on track. There are a few easy bolt-in solutions e.g. Kirk, Auto Power. Better to be safe.

4. Race Seat

If you’re running a roll bar or cage, it’s very important you run a proper harness/seat belt because in case of an accident, you may hit your head on the roll bar/cage. From time to time, I see drivers running a roll bar in their street car with a street seat. That is not safe. You should be properly strapped into a bucket seat with shoulder straps.

5. Race Harness

We recommend at least a 5-point racing harness. A 5-point includes 2 shoulder straps, 2 side belts and an anti-submarine belt which prevents you from sliding underneath your belts in high G situations. Also another thing to consider is if you’re running a HANS device (neck restraint) there are 2″ to 3″ belts since HANS recommends using a 2″ belt.

6. Steering Wheel

You should not get an aftermarket steering wheel without getting a cage, race seat and and harness. Not a good idea to remove OEM airbags without proper supporting safety equipment. An aftermarket steering wheel can provide weight reduction benefits, quick-release for ease of access and improved ergonomics with a change in diameter.

7. Fire Suppression

Incase of a fire situation, you want to be prepared with a fire suppression system. The easiest thing to do is get a handheld extinguisher with a quick release mount. There are plenty of quick release mounting options on eBay as well.

16-20 Track Days

1. Oil Diverter Valve

Are you seeing high oil temps? You can reduce oil temps by about 30+ degrees with a simple oil diverter kit. The OEM oil filter housing limits the amount of oil flow to warm up the car faster so this kit allows a “full-flow” to cool the oil temps. This is not recommend for street cars unless you add a performance inline thermostat as you won’t each safe operating temps.

2. Big Brake Kit

Are you experiencing brake fade? The stock brake system utilizes a 325mm (328mm for ZCP/CSL) rotor in the front which may overheat on track. A big brake kit can help with cooling and overall braking performance.

3. VANOS High Pressure Oil Line

The factory VANOS high pressure line has a high failure rate for track cars. The metal gets brittle over time and cracks. Failure to the VANOS line can be catastrophic so replacing it with a stainless steel line is the best way to go. This is a mandatory item per our Ultimate Maintenance Guide.

4. Brake Ducts

If you’re still overheating your BBK, then it is time for some brake ducts. Brake ducts will allow air to feed into a backing plate, provided in most kits, which then feeds to the back of the rotors.

20+ Track Days

1. Differential

It’s all about getting the power down to the wheels. The factory M Variable limited slip differential is good, but it doesn’t perform as well as say a 3-clutch diff. The OEM also wears out fast. According to Diffs Online you need to refresh the diff in about 80k miles. If you don’t have a ton of money to shell out on a new diff, a great alternative is to change the R&P to a 3.91 or 4.1 – poor man’s supercharger.

2. Aero

Want more grip? A proper wing, diffuser and front splitter setup can increase downforce significantly providing more grip at speeds. We’ve created our own splitter brackets for the E46 M3 featuring a quick-release to install/remove in seconds. Check out our store for more aero products.

3. Lexan/Poly Windows

Polycarbonate windows can save you some unwanted weight and can also provide some aero/cooling benefits with the use of NACA ducts.

4. Full Cage

Safety is the #1 reason why you should get a full cage, but there are added benefits of going full e.g. tie-in the cage to the front/rear struts for additional chassis rigidity. Also with proper side/door protection, you can remove the OEM doors for a lightweight one. TC Design in Northern California is one of the best fabricators in the USA.

5. Carbon Fiber Trunk

The OEM trunk weighs in at about 45 lbs. A carbon fiber or even fiberglass can save 30+ pounds of weight. You can pickup a CSL style carbon fiber trunk for improved styling as well.

6. ZF 5-Speed Transmission

If you want to save even more weight, you can swap in a ZF 5-speed transmission from an E36 M3. Some drivers say it provides better shifting points on track, but that largely depends on the track itself. The weight difference from a stock E46 M3 transmissions vs the ZF 5-Speed is about 5-10 pounds, but if you’re scraping for weight, it all adds up.

Moroso Oil Catch Can and Expansion Tank Review - E46 M3

Moroso Oil Catch Can Review - E46 M3

What is a PCV system?

The goal of a positive crankcase ventilation (PCV) system is to limit the amount of residual oil and vapor, that is released from the crankcase, from entering back into the throttle bodies inside the intake plenum. Overtime oil can build up around your throttle bodies, combustion chambers and idle control valve (ICV) valve which can lead to various performance issues such as rough idling.

Although most cars have some sort of PCV system, it’s still not enough. That’s evident when owners have to clean their throttle bodies and ICV valve. We made an article on how to clean that for this reason and you can check it out here: E46 M3 Throttle Body and ICV Cleaning DIY.

⚠️ Disclosure: Some of the links in this article are affiliate links, meaning, at no additional cost to you, we will earn a commission if you click through and make a purchase. We thank you for your support. 🙏

E46 M3 Throttle Body and ICV Cleaning
E46 M3 Throttle Body and ICV Cleaning

So how does the oil catch can make a difference?

The oil catch can simply routes the residual oil and vapor from the crankcase into an isolated container opposed to routing it back to the intake plenum.

If you ever remove your intake plenum, you’ll notice the small oil vent line connected underneath. This routes back to the oil pan. But think about it, you’re really trying to force the vapor and oil from the crankcase, through the breather tube, into the plenum, somehow bypasses the intake trumpets, and seeps downwards into the small hole? Why not just stop it from entering the plenum in the first place? That’s the idea of the oil/air separator AKA catch can.

E46 M3 Throttle Body and ICV Cleaning
E46 M3 Throttle Body and ICV Cleaning

Is the catch can worth it?

Regardless of your usage, by the book the answer is always yes. You don’t want to recirculate dirty oil and vapors back into the plenum. Check out the video of how much stuff came out. This is the results after maybe 4 track days.

The Moroso setup

There are several catch cans out there, but I chose the Moroso simply because of engine bay aesthetics. I have a matching Moroso Expansion Tank for the coolant and the generic catch can they sell perfectly mounts into my existing air pump bracket. It’s like it was meant to be!

Moroso Oil Catch Can and Expansion Tank Review - E46 M3

Moroso Universal Air/Oil Separator

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Moroso Expansion Tank

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Moroso Oil Catch Can and Expansion Tank Review - E46 M3
Moroso Oil Catch Can and Expansion Tank Review - E46 M3
Moroso Oil Catch Can and Expansion Tank Review - E46 M3

Turner CSL Intake Dyno for E46 M3

Turner Motorsport CSL Style Intake Unboxing, Review, Dyno Results

Overview of the Turner Motorsport CSL Style Intake

I decided to run a CSL style carbon fiber intake on my track E46 M3 to see if I can squeeze more horespower. Let’s be honest though, the looks and sound is probably half the reason why most of us justify the cost – including me. However, it’s easier to justify a CSL intake now because Turner Motorsport have developed their own version of the CSL intake.

The price? It’s very reasonable considering competitors. They have an intake-only option for $1,499, but they are also providing kit options starting at $1,999.95.


  • The Turner Motorsport CSL Intake (w/ supporting mods) made a solid +54.23 whp and +17.84 wtq over stock engine setup.
  • Bare minimum cost to fully convert into CSL intake is around $2,530 for 6MT; around $2,690 for SMG.
  • Carbon fiber quality is great, however weave pattern runs opposite of authentic CSL.
  • Initial production batch comes with weak epoxy points for hose connectors.

Disclosure: Some of the links in this article are affiliate links, meaning, at no additional cost to you, we will earn a commission if you click through and make a purchase. We thank you for your support. 🙏

Turner Motorsport CSL Style Intake

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Unboxing the Turner Motorsport CSL Style Intake

ECS has an intake line designed in house which is produced under the name Kohlefaser Luft-Technik however the Turner CSL Intake is not the same. When I received the package I was honestly surprised how small the box was. When I opened it up, I noticed there wasn’t a lot of side padding for protections so I held my breath hoping nothing got damaged.

⚠️ Edit 6/17/2020: A representative from Turner reached out to me and confirmed these are not "white label" but developed in-house by the Turner engineering team with many hours going into the R&D. Their trumpet design is in fact different than the OE CSL box and designed to produce more airflow.

I did a full inspection and luckily nothing was damaged! All breather hose valves, IAT bungs and overall structure of the intake was nice and clean. By the time I publish this article I will probably already have notified them of the packaging recommendations. I would hate to receive this intake damaged. However I do want to point out, as I did in the DIY guide, the epoxy for the lower breather tube that connects to the ICV is weak and it actually detached while I was installing the hose. This is something I’m sure they’ll improve for later production runs.

The entire carbon fiber structure of the intake is composed of two parts: intake body and inlet. The trumpets on the intake body appear very nice and is a 1-piece mold part of the entire intake body.

I also noticed the carbon fiber weave is going a different direction than the OEM CSL airbox. You probably won’t have noticed it and it’s not a big deal to me, but just something I noticed.

Turner Motorsport CSL Style Intake Review and Install DIY - E46 M3
Turner Motorsport CSL Style Intake Review and Install DIY - E46 M3
Turner Motorsport CSL Style Intake Review and Install DIY - E46 M3

Dyno Testing

⚠️ Update 8/17/2020: A lot of people seem to be in shock from the dyno results and I suspect some people are selectively reading this article. So for those that want extra clear cliff notes, here they are:

  1. “No way it’s 52 whp gain!” – Yes way. The comparison is against a completely bone stock car – not just a stock intake. Read the dyno chart please. I have notes contained at the bottom to compare all my historical dyno results. I’ve dyno’d my car there for a very long time now so I have data on a lot of different setups. Again, please read.
  2. “Dyno numbers are way too high!” – Dyno numbers are subjective. There are too many variables with different types of dynos and they all read a little or a lot differently. Even the same dyno/model can read a little differently. The point here is, I eliminated the variable as much as possible by testing on the same dyno. Same car, same altitude, similar temps. If the CSL airbox dyno results seem high, then compare it against the other setup results. The other results are “high” as well. So what does that mean? As long as it’s an apples to apples comparison on the same dyno and car, the delta difference is what you need to look at. Again, I detailed this in the article and I’m not sure why there is so much confusion.
  3. “OMG. He must have some secret mods.” – No. I’m simply running an OEM CSL tune, Turner Motorsport airbox, headers, BW exhaust. No cams. No crazy engine internals. If you’re seriously doubting these results, go ahead and call EAS and tell them your story on dyno numbers.

Just as we do for all of our dyno tunes and testing, we went to European Auto Source in Anaheim, CA to run the dyno. We have historical data with our previous setups, so we can benchmark the data with stock and other modified setups. In the dyno chart below, we compare 5 different runs – all from the same car. Keep in mind these tests were not done all on the same day, so there are minor factors that come into play such as varying temperature, humidity, engine health, exhaust setups, etc.

Setups Tested

Details on the supporting parts are outlined in the bottom of the dyno chart e.g. Stock (91 octane) run is on catted headers, RE exhaust, stock intake.

  1. Stock (91 octane)
  2. Catless + B-Spec Tune (91 octane)
  3. Catless + B-Spec Tune + Eventuri intake (91 octane)
  4. Catless + MSS54HP CSL + CSL intake (91 octane)
  5. Catless + MSS54HP CSL + CSL intake (~E35 blend)

Gains Comparison vs Catless + MSS54HP CSL + CSL Intake (91 Octane)

Comparison is against the 91 octane run since for us in CA this simulates a more realistic scenario as we don’t have 93 octane at the pump. 93 octane testing was done for additional insights.

Setup WHP WHP Gain Δ WTQ WTQ Gain Δ
Stock (91 octane) 286.37 54.23 19% 245.43 17.84 7%
Catless + B-Spec Tune (91 octane) 315.01 25.59 8% 247.33 15.94 6%
Catless + B-Spec Tune + Eventuri intake (91 octane) 321.17 19.43 6% 246.23 17.04 7%

Parts List & Cost

The table below is a full parts list to do the Turner Motorsport CSL Intake conversion. Again, this is a full parts list. If you read the DIY article we put out, you’ll find out exactly what I did and did not use. You don’t need to buy everything in the parts list.

Quantity Item Price Link
1 CSL Style Intake – Gloss  $1,499.95 View Product
1 CSL Style Intake – Matte  $1,499.95 View Product
1 CSL Vent Valve Bracket  $41.00 View Product
2 Washer  N/A View Product
1 Hex Bolt  $1.05 View Product
2 Hex Nut  $0.99 View Product
1 CSL Air Shut Off Valve  $111.95 View Product
1 CSL Air Filter  $149.95 View Product
1 S54 Silicone Throttle Body Boot Set  $109.95 View Product
1 Turner Plug-And-Play IAT Relocation Kit  $117.90 View Product
1 CSL IAT Sensor  $26.95 View Product

Additional for SMG

1 CSL SMG Expansion Tank Bracket  $29.95 View Product
1 CSL SMG Expansion Tank  $128.95 View Product


1 CSL Dipstick Tube  $89.95 View Product
1 CSL Oil Dipstick  $32.95 View Product

Along with the parts you need to buy for the CSL airbox, you also need to figure out your ECU and Alpha-N/MAP sensor setup. That is not baked into the parts list cost.


The earlier E46 M3 models came with an MSS54 ECU while the later models came with an updated MSS54HP ECU. In order to run the CSL tune, you need the MSS54HP ECU. There are various shops that can make the conversion to MSS54HP ECU such as Kassel Performance. If you want a custom tune, well that’s going to be more.

MAP Sensor

What is a MAP Sensor? Well we did an article for that and you can take a read on our Wire MAP and IAT Sensor for MSS54HP CSL ECU DIY guide first. TLDR: If you want to run a CSL box you have two options 1. Alpha-N or 2. MAP sensor. The following chart below is under the assumption of a MAP sensor with a MSS54 non-HP ECU conversion.

Quantity Item Price
1 MSS54HP CSL ECU (Kassel)  $     460.00
1 BMW E46 M3 S54 CSL MAP Sensor Conversion Kit  $     235.00


If you don’t want to do the MAP sensor route, you can choose Alpha-N tuning. These are hard coded values your engine uses to calculate load. Since it does not have a MAP sensor to calculate air mass, it uses throttle position and RPM to calculate load. There is a lot of debate for MAP vs Alpha-N, but the best way to go is using a MAP sensor since it can calculate dynamic changes in the environment e.g. higher elevation conditions where there is less oxygen. This is especially important in areas/tracks that experience large temperature fluctuations within a span of hours. Alpha-N requires custom tuning and is usually more than the price of a MAP kit.

Turner Motorsport CSL Intake DIY

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Final Thoughts

So there you have it. A look at the Turner Motorsport CSL Intake with comprehensive dyno testing. Let me know in the comments below on what you think of this kit and whether or not you would consider buying this.