Afternoon all, after spending more hours reading LNF tuning guides than I care to recall. I jumped into my first one. The car I am tuning is an 08 Sky Redline M5 with an intake tube and turbo back exhaust (no cat).
So after spending a couple of hours with the car I feel that I have come up with a tune that is pretty solid. Here is a breakdown of what issues I am currently having.
Please see the tune, log and config below. I am using the standard LNF config with a couple of changes. I did also install a LM1 in the rear O2 sensor bung (don't trust this newfangled technology
1st off: I am having boost taper issues above 5,000 rpm. You can see it in the data log I posted below (starting at from 2600). The car is running perfect at 260kpa at 82% DC, at 5,000 rpm the DC% (and boost) starts to taper. I am sure this is something that I have overlooked with TM or..... I have read a bunch of posts on how to eliminate this but have not found a definitive answer.
2nd Issue: I am seeing knock retard when adding just a couple of degrees of timing @ WOT (also see in the log posted). I have heard that many people are running 15-16* and I am know where near that. Does it seems unusual that I am limited with the timing that I am running?
3rd issue: NOT PRESENT in the data log. I am having a substantial timing dropout when the car comes into boost around or below 3000 rpm. I found a thread that goes over this but again did not find a solution.
Thanks to everyone that has put in so much time and effort making the information on tuning these engines available. There is an overwhelming amount of information on this forum. I will hopefully be able to add to it by the time I am done with this car.
As a side note I have not touched the cam timing tables and only dabbled with timing. I come from the LS world and these engines are completely different to me. I understand there is some privacy due to $$$ and not everyone wants to show their cards. If anyone would feel more comfortable sharing through PM please feel free.
Thanks in advance!