Mike and Jeremy flew out to Houston this past weekend to tune some cars here in Texas. I had a great time hanging out with these guys. They're a lot of fun and true car guys. Even more importantly, Jeremy is a mad scientist and spent hours on each car tweaking things until the cars ran as smoothly and as powerfully as possible. Many, many thanks are due to Mike for his tireless efforts to pull this group buy together and make it happen despite a few hiccups.
The Results
I'm sure all of you have seen Nawaaz's numbers. It's very important to me to keep my car close to stock in terms of every day driveability, so I obviously don't have the same numbers he does, but the gains from the PowerChip tune itself are at least as impressive. All I have on my car is the Dinan axle-back exhaust and MS filter. Without further ado, here are the results:
**UPDATE: SEE PAGE 2 FOR CORRECT DYNO CHART**
The baseline is the best of three initial runs. The tuned run was my best run in terms of power, but not torque (I had another run where I hit 252 lb-ft). One thing to keep in mind is how warm it was. It was the middle of the afternoon and the temp was about 90 degrees on the dyno. The most impressive thing to me looking at this chart is the size of the gains throughout the whole range. This tune doesn't just improve the top end. The 16 whp/16 lb-ft improvement at 5500 rpm is very noticeable.
Driving Impressions
I have to admit that, despite all of the favorable reviews that Mike, Jeremy and PowerChip have received on m3post, my expectations were low. The S65is, after all, a finely tuned, high-compression, NA motor putting out 414 bhp. I wasn't expecting huge gains, and I wasn't expecting to be able to feel much, especially since I've spoken to guys with flashes from other tuners who didn't notice any difference at all.
Immediately after the car was off the dyno, I took it for a romp. I wasn't expecting to notice much improvement, but the difference was stunning. Down low it's noticeably more peppy and MUCH smoother, but right at 5k rpm the motor gets a second wind and just launches forward like a scalded cat. I feel like I have to relearn how to drive this car hard because the rear tires now break loose in many more situations than before. I can't wait to get some wider rubber in back.
What doesn't show up on the chart is that the throttle response and power delivery is so much smoother, especially while the car is still warming up. Before, when easing off the clutch and onto the throttle in first gear, I'd get stuck in a bad jerky cycle, like it was my first time driving a MT. That no longer occurs, even though the throttle tip-in is now more sensitive. This alone was worth the price of admission.
Conclusion
I was very much on the fence about getting a tune at all, but I'm very, very glad that I pulled the trigger. If I had known how much of an improvement I was going to get, I wouldn't have debated the decision for so long. I'm also glad I went through Mike and Jeremy. They were very responsive to my questions, went above and beyond to get each car just right, and I know that if any issues were to arise, they'll take care of me.