B-Spec Tune – BMW E46 M3

(76 customer reviews)

The B-Spec Tune is an off-the-shelf (OTS) E46 M3 MAF-based E-Flash tune that delivers a smooth power band all the way to redline while improving engine performance over stock. Get up to 30 whp / 15 wtq over baseline tune with 16+ free add-on features. We do not support forced induction (FI) or Alpha N configurations at this time. Tuning may take up to 5 business days, from the time we have your bin file and screenshot, to complete.

⚠️ None of our tuning products can be used at any time on any emissions control vehicle that is used for anything other than off-road/track performance and shall not be used on public roads. We have the right to cancel your order if deemed necessary.


Details of each feature in the Add-On Features section below.
Shift Lights are not guaranteed to work; may vary by individual clusters.

Choose your desired fueling. Higher octane ratings will have reduced knock adaptions as stock setting are designed for 91 AKI octane. This will still leave the main knock detection program active but reduces the knock adaption values as they are overly sensitive. High octane will be considered 93 octane AKI or greater in the US, 98 octane RON or greater in the EU, or E30 to E85 mixture. Do not select 93 octane if you only have access to 91, you will lose power via DME pulling timing.

Select your drivetrain mode configuration. OEM will leave your throttle response alone. Sport Enhanced will remap your sport mode throttle pedal sensitivity to be more linear. Sport Plus will remap numerous maps including sport enhanced features as well. Sport Plus is recommended.

Crackles and pops with throttle taps. Make your exhaust set up sound even more aggressive. For aftermarket headers/section 1 only.

Put your pedal to the floor and have your RPM bounce at the desired limiter to achieve consistent launch from stand still. This feature will disable Dyno Mode. SMG AND 6MT can also choose Dyno mode if you do not want launch control. We recommend 3,100 RPM.

Ability to raise your redline rev limiter past stock 8,000 rpm. We recommend 8,100 RPM.

Idle settings upon first 30 seconds of startup.

Standing idle settings after first 30 seconds of startup. Raised idle is for those with solid/poly engine mounts with increased NVH.

YEAR 2001-2003 ONLY. 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.

Please submit a picture of the location of your MK20 DSC unit to ensure compatibility with the Sport DSC tune if you would like this DSC tune to be applied.

(max file size 128 MB)

CSL SMG Tune Options

Upload your stock tune bin file (.bin) for the E-Flash method. We will also require you to submit a screenshot of your current DME Error Logs before we send you the tune to ensure safe flashing. If you require assistance, we can help you after order is placed. Stock Partial BIN file (file size should be 32kb or 64kb)

(max file size 128 MB)

Upload a screenshot of your DME errors. JPG and PNG accepted.

(max file size 128 MB)

SKU 3545 Categories , Tag

Up to 30+ WHP Increase

Dyno-proven horsepower gains. B-Spec Tune will deliver a smooth power band all the way to redline while improving engine performance over stock.

B-Spec Tune

Remote Tuning

Flash your car with our Remote Tuning support. All you need is a cable and computer.

B-Spec Tune Dyno - E46 M3









B-Spec Tune - Buildjournal Exhaust Backfire Tune - Tuning Labs

1. Extract your current bin file using BMWFlash. Read our DIY here: How to Extract & Flash BIN File with BMWFlash

  1. Take a screenshot of your current ECU/DME logs. Read our DIY here: How to Read & Diagnose Check Engine Light via BMWLogger
  2. Upload both the extracted bin and screenshot of your logs with your tune order above

B-Spec Tune - Buildjournal Exhaust Backfire Tune - Tuning Labs

No steps necessary here!

B-Spec Tune - Buildjournal Exhaust Backfire Tune - Tuning Labs

-We will send you a new bin file

-Flash your new bin file using BMWFlash. Read our DIY here: How to Extract & Flash BIN File with BMWFlash

16+ Free Add-Ons

For a full description of each B-Spec E46 M3 tune add-on feature and what it does, check out ECUWorx’s website or email us at info@thebuildjournal.com for a list of recommended add-ons for your setup.

In addition, we have a couple of features that are not on the list:

Valet Mode – Overrides your ‘Comfort’ Mode (Sport mode off) to limit peak power and acceleration. Ideal use case is to drive normally with the ‘Sport’ button on and turn it off for Valet Mode situations.

Sport Enhanced Mode – Overrides your ‘Sport’ Mode (Sport mode on) with our custom linear-throttle remapping. This add-on feature gives you a more consistent feel to the throttle press.

Sport Plus Mode – All the features of Sport Enhanced plus some additional torque management changes and WOT map changes.

Raised Idle – Reduces NVH for those who are running poly or solid motor mounts.

Sport Fan Curve – Rescaled the curves that determines the auxiliary fan functions for better cooling during idling.

Ignition Cut Off  – When your car hits the rev limiter, on the stock ECU there are 2 stages of cutting power. First is fuel cut and the second stage is ignition cut. Fuel cut results in slower pickup in power vs ignition based cut off.

Sport DSC Tune – Similar to M-Track Mode, sport DSC Tune will override stock MK20 DSC parameters and ignition cut off so it is less intrusive during spirited driving.

Addition or removal of most add-on selections are free, however a re-tune fee will only apply. Please visit the Re-tune Service for B-Spec Tune page to submit your change request.







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Tuning & Software

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