Fall Line revisited: Dyno testing the E9x M3 Eisenmann Race Performance
A couple of us from IND had a chance to go to Fall Line Motorsports to dyno our Eisenmann Race exhaust system, and I was so excited about the results, I wanted to share them with the forum as soon as possible! With Fall Line’s busy schedule, and our constant Eisenmann shipments arriving and leaving, it’s quite difficult to make time to dyno a system, but the sound of the Eisenmann revving all the way to 8,000rpm was well worth it!
BMW blog – http://www.bmwblog.com/2009/02/19/ei…2-m3-dyno-day/
When we arrived at Fall Line, they had one of their own E92 M3s up on a dyno, ready to install our Eisenmann system. We felt that using someone else’s car, in bone stock form, was the most unbiased way to test the exhaust. Fall Line had just finished dynoing the car in stock form earlier that day.
Look at the grippy Michelin Pilot Sport Cup tires! These have gotten to be pretty infamous because of the M3 CSL.
Here’s the stock system, next to our Eisenmann Race.
Fall Line’s technician installed the system in about a half an hour, using Eisenmann’s new connecting pipes.
Here’s another shot of the Eisenmann system installed on the car.
The E92 M3 rolled back on to Fall Line’s all wheel drive Mustang dyno, and I was already getting shivers down my spine as the car’s exhaust note echoed off the building walls. As the Eisenmann system had never before been dynoed, I knew that something truly unique was about to happen. 
Although I hadn’t seen the E92 M3 Eisenmann system tested in terms of actual power output, I was confident that Eisenmann’s exhaust would be much more efficient than the OEM muffler, due to their hundreds of hours of testing on machines such as this one, that simulate exhaust flow through various canister designs to optimize efficiency. Eisenmann does not release horsepower figures, as they are actually less precise than the flow efficiency readings Eisenmann is capable of generating at their facility!
As the dyno run started, I was absolutely deafened by Fall Line’s 70mph fan. I’ve been to many dyno facilities, and have never seen a fan of this size. This fan allows for very repeatable tests, as it simulates real airflow through the car’s cooling systems.
The numbers achieved were very impressive indeed: the M3, equipped with the factory exhaust system, achieved 351 wheel horsepower, a very realistic number when considering the car’s 400 crank horsepower rating, and the repeated runs that corroborated this number. This M3, when tested with the Eisenmann system only an hour and a half later, produced 364hp at peak- a 13hp gain! Even more interestingly, 100rpm earlier, at 7900 RPM, the Eisenmann system produced 363hp, while the factory system only allowed the car to produce 348hp- a 15hp gain!
Here’s a screen shot of the dyno graph of this particular stock vs Eisenmann run. Because Fall Line is a very busy shop, I have not yet received the data from the many other runs, and therefore can’t yet post a dyno graph of the average of the runs, or the correction factors used, or conditions during the run. I’ll continue to update this post as more information comes in. The highest gain seen with the Eisenmann system was 16 wheel horsepower, while the lowest gain seen was 15 wheel horsepower, so the final dyno graph should not change much.
Although this doesn’t have anything to do with our dyno testing, I just wanted to post another photo of my current automotive crush: this beautiful white 997 Cup car. The car’s level of preparation from the factory is simply astonishing. This car is truly one of the most gorgeous factory built racecars I’ve ever seen.
I hope this information was useful to everyone! I’ll keep people updated as we release dyno test conditions and averaged runs.
