Recently in Frequently Asked Questions Category

BMW Performance Steering Wheel Installation Guide

Here's the BMW Performance Steering Wheel installation guide. Thanks to MEPost user 'ihyln' for providing the PDF.


WARNING: The cost of running leaded race fuel

During the run up to the Mojave Mile and Texas Mile, we started adding some VP Racing Q16 leaded race gasoline to boost our performance. Between Mojave and Texas, we switched to 100% Q16 and retuned the car for it. Q16 seemed like a logical choice because it's very high octane, leaded, and oxygenated -- just what we need for the moisture-rich Texas weather. I figured, I'm catless -- so what's the problem? ZZZZZZZZZt. WRONG ANSWER.

How to program your own vehicle

During the investigation of retrofitting the 09 iDrive into an earlier vehicle, I bought all of the programming tools necessary to do my own vehicle coding. The plan was to use the actual BMW tools and software, and not bootleg versions. It turns out that the retrofit is not really feasible, so I kind of put it on the back-burner. So now what do I do with the tools besides sell them or figure out how to program my own vehicle?

Exposing DYNO cheaters: how they do it, and how to catch them

Dyno Cheating:

As this thread states, its purpose is to discuss dyno cheating, how it's done, and how to prevent it. I'm hoping that people familiar with different dyno brands will lend their expertise to this discussion to help expose and prevent dyno cheating. As new dynos are discussed, I'll roll up the results into this message. If there's enough interest in this thread, I'll eventually make it a sticky.

BMW Motorsport High Performance Clutch

Here is a picture of the new 3-disc (tri-mass) racing clutch and flywheel from BMW Motorsport. As far as I know, this clutch does not yet appear in BMW Motorsport catalogs. Also attached in a PDF file with higher resolution of the same picture.

Octane rating conversions

Here's a set of conversion tables I worked up for octane ratings. The European octane rating is RON, where as the US octane rating is an average of (RON+MON)/2. The following table comes from the following web site:

Choosing the correct Final Drive Ratio and Differential

If you're considering changing the final drive ratio in your BMW, the cheapest approach is to simply replace your existing final drive ratio with one of Dan's @ DiffsOnline. But there are also options to replace your differential at the same time. I'll explain those options below.

6MT and DCT Final Drive Comparison

In this original thread on m3post (here), the discussion started with a comparision of the stock 3.85 final drive and the new Dinan 4.10 final drive for the 6MT. Soon that discussion morphed into a general comparison between 6MT and DCT and all combinations of final drive ratios.

Removing and replacing the ECU

Here's instructions for removing and replacing the ECU. These instructions are specific to the E9x M3's and will be slightly different on E9x 335's.

BMW E9x M3 ECU Removal.pdf

Gruppe-M Cold Air Intake installation guide.

Installation instructions for the Gruppe-M Cold Air Intake.


I thought it would be a good idea to write up instructions for dynoing the M3 motor on a hub-attached dyno. Hub-attached dyno's (such as the Dynapack, and Rototest) are going to offer the most accurate results -- far more accurate than any type of roller, or chassis dyno. Hub-attached dynos are more accurate because they operate on the same principles as a real motor dyno. Motor dyno's work by running the motor at wide-open-throttle, then applying a hydraulic load on the motor until it bogs down to a specified RPM. Once you arrive at your desired RPM, a torque sensors measures the amount of torque at the crankshaft.

Configuration Settings for BMW "Premium Sound"

Early-on when I purchased my car, I noticed that the "Premium Sound" really sucked.  I started a thread at M3Post discussing the topic.  As the thread progressed, of course there were many people who disagreed with my analysis.  I have some very sophisticated recording equipment, so I brought it into my car, captured a spectrum analysis, and created some settings that "fixed" (or at least flattened out) the sound.  These settings are now widely used by other M3 owners and reposted and advertised on many different car forums and threads.

How to View and Compare Dynapack Dyno Files

Until I supercharged my car, most all of my dyno performance tests were performed on a Dynapack dynamometer.  With your original dyno files and the right tools, it's easy to view, compare, and print your own Dynapack dyno results.  Below are detailed instructions for viewing and comparing files from a Dynapack dyno.

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