Quote:
Originally Posted by Mike Benvo
Thanks for your questions - I have always appreciated your thoroughness.
1. I am going simply based on what the owner Shawn Church told me. He told me that stock M3's normally put down around 365. The Microsoft M3 put down 375 I believe, but I have not looked closely at the graph to see where that car peeked. I just included it for general illustration purposes. I wouldn't say that it's a matter of the new M3's putting down more power, maybe more of a factor of extremely old software revisions such as 60E being put up against 231E. Or it could be hardware related, such as aged spark plugs or oxygen sensors coupled with old software that may have a cumulative effect. I have driven at least twenty 2012 M3's, and they feel the same as my car (and have that new car smell!).
2. No tuner is going to be able to remedy this 100% completely. However, there are changes I make to make it a hell of a lot better. I have had long conversations with Sal about this. When you look at the factory vanos mapping, it has some interesting changes in stock form in the exact akra dip area. The scaling on the map is also different there as well. It's almost as if the factory was trying to tune out some sort of engine resonance issue and that the Akra just exacerbates it. My test files for the dyno did not contain any changes below 3,000 RPM as I was trying to go for midrange torque and top end power. However, my standard tunes do have changes in all areas. I was on a pretty heavy time constraint there. Having only an hour to flash and tune the file between runs was certainly not enough. I think if I had more time that I could have achieved higher gains. This was just a 'quick test'.
3. I have dynoed on dynojets before. This was my first time on a Dynapack and I was surprised to see the numbers. I am no expert on dyno's themselves, but theoretically not having the wheels and tires mounted to the hubs could signify less loss. Someone with more knowledge on dyno's themselves and the differences might be a better resource for this. I only know the tuning and programming stuff  .
Regardless, here is a dyno from a dynojet last year (before and after tune): |
I am convinced that the dip is most likely due to valve overlap in that area. If I were going to try and deal with it I would try and retard intake cam timing and see if it helps. If that didn't deal with it I would then try and advance exhaust cam timing a little bit to get the results that I was seeking. Basically what I would be trying to do in this case would be increasing the lobe separation of the intake and exhaust (technically lobe separation refers to single cam engines but the same principle exists depending on your baseline timing of intake and exhaust cams in a twin cam engine).
I am no software engineer, my software modification experience is mostly limited to fuel injection timing, fuel injection duration and boost pressure on a diesel engine. I am just saying what one would do with base cam timing on a gasoline engine to try and make more torque lower in the rev range. There may be limitations that I am unaware of with the MSS60 and the cam phasing system that may limit the amount you could do with cam timing that low in the rev range.
P.S. Are the dyno graphs in WHP??? If so, Nice numbers and good work with the software!