Unfortunately, when a motor is as well-engineered from the factory as the S65 in our E90 M3, it leaves little for the aftermarket to improve upon without spending big bucks building the motor or going forced induction. However, ESS Tuning has years of experience with BMWs and provided us with their E-Flash ECU Software as well as their Performance DCT Transmission software to squeeze out even more performance from an already highly-strung motor.
Our M3’s S65 4.0L V8 is a marvelous engine. Pumping out 414hp with an 8,300rpm redline, it’s in an elite company of cars that make over 100hp/L. But what makes the engine’s figures impressive is also what makes it incredibly difficult to extract more power from. The M3’s naturally aspirated competitors have an extra 1-2L+ of displacement in order to make similar power. While less efficient, anything you can do to free up the intake and exhaust of those big motors yields significant power gains.
In order for the M3 to be competitive, the wizards at BMW’s M-division maxed out the motor from the factory with 8 individual throttle bodies, a massive intake plenum with a giant tube going to the air filter, and proper 4-1 equal length headers with spiked merge collectors. This means there’s really not much to be gained from intake or exhaust modifications, so we will have to look elsewhere for power.
European Supercharging Systems (ESS Tuning) was founded in 1995 in Aremark, Norway and is the world’s largest BMW supercharger system manufacturer. With facilities in Europe, Southern California and Phoenix, ESS spends countless hours on the dyno, road, and track testing all over the world to ensure that their products and software are of the highest caliber and enhance the performance of the car without compromising comfort, drivability, durability, emissions and fuel economy under all conditions. They even put their development cars through 50,000 mile long term track, extreme heat and cold, extended high-speed Autobahn, and normal everyday driving testing.
We got our tuning kit and made a short trip just down the street from my home in Mooresville, NC to my buddies at Roush Yates Performance. As some of you might know, I drove for Roush in the Grand-Am Continental Tires series for 4 years and our #61 Mustang GS racecar has been on their Dynojet 224xLC series load-testing dynamometer many times, as well as countless NASCAR Trucks, NW, and Sprint Cup cars. This loading-dynamometer is similar to the more conservative reading Mustang dynos and my own E36 M3 read exactly the same output on this Dynojet 224xLC as it did on a Mustang 1100SE on the same day. For good measure, Roush Yates also has a Dynojet 248 sitting right next to the 224xLC.
Strapped down to the Dyno and after a few runs, our E90 M3 pumped out an average of 337whp @ 8,200rpm 241 lb/ft of torque @ 3,900rpm. We dyno’d our 7-speed DCT transmission in 5th gear. Despite 7th gear having a 1:1 ratio its final drive would have the rollers spinning too fast so 4th and 5th gears are typically used in DCT equipped cars.