dan0617 wrote:
Congrats! Nice improvements. I think your tune is closer than alot of people think, but needs a little work. I'm guessing from what I'm seeing you are going a little too lean for the amount of timing you are running in that area of the tune. It is pulling timing I'd bet.

I found through track testing that my car makes it's best power at 12.2 to 12.7 afr. Anything over 13 and I lose power, no matter where I set the timing. Anything under 12 and I also seem to lose power, but not as much as I lose when I approach 13.5 afr.

If you get the afr's dialed down to less than 13 everywhere and you think it is pulling timing due to false knock, cut the brown wire that is coming out of the knock module. I tried the LT4 knock module and now I even have the elusive 4.3 caprice knock module, and still got some false knock. I cut the brown wire so it disables the knock retard but doesn't throw any codes. I then put a male connector on one end and female on the other so I can plug it back in anytime I want. Just listen closely for pinging when making runs, it will sound like someone shaking popcorn kernels in a tin can. Keep advancing timing, and watch the afr's as every 2 or so degrees of timing you gain without detonation you will need to add more fuel. When you hear any detonation abort the run, go back, pull out 2 degrees of timing, and you found the sweet spot.


What tires are you running? I used Nitto drag radials and with a fast roll down of the throttle, after a good tire heating, it would dead hook and I'd get 1.6X 60' times every pass. I went to MT ET street radials, and I could get those times (and 1.5X 60' times when spraying just after getting my foot to the floor) with very little tire heating. The tread doesn't last as long tho. Only suspension mods are removing the front sway bar (you could disconnect yours to see if it helps, without removing it), and setting the rear alignment to +1.5 degrees camber. I run around 17 to 18 psi in the rear tires when drag racing.

Doing these things, you should be able to run with or beat my N/A times. My best so far was a 12.08 @ 113. Was consistently 12.15 to 12.20 last season, on the 3.07 gears. I'm guessing this year, since I went to 3.45 gears and a D44 so I can launch harder, and some more tuning, that I'll get an 11.90 or maybe 11.80. I'm betting you will get that, I'm guessing your car is lighter than mine. I'm sitting at 3520 with me in it.