Strange 10HP loss up top...

**blackwidow99** · 06-26-2007, 07:26 PM

Had it tuned at Vengeance Racing in Atlanta. Great guys, brilliant tuning, and famed creators of the Vindicator cam grinds.

Couldn't figure out the cause of this 10HP loss up top. The car is a 1999 Camaro SS with Hooker LTs, SLP LM1, LS6 Intake, TB P&P, SLP Lid, NGK tr55's, K&N, and an SLP MAF plus the Vengeance Dyno-tune.

We tried removing the SLP MAF because they are known to be crappy, but it didn't solve the problem.

Any ideas?

**blackwidow99** · 06-27-2007, 09:02 AM

TTT for day crowd

**JEFF01Z** · 06-27-2007, 09:22 AM

The dip in HP came from the sudden drop in TQ, then it came back up a little. Remember HP is directly related to TQ. Just guessing it looks like you may be picking up some knock and getting some KR, which will reduce torque. I guessing you made multiple runs, so that should eliminate a glitch in the dyno reading.
To get a better understanding of exactly what is going on, a run with A/F logged would be helpful in understanding the source of the problem.
The pattern fits KR theory. If it is the problem, why are you getting it? Maybe it is going lean at that point.

**blackwidow99** · 06-27-2007, 11:14 AM

Hmmm I know less about tuning than anyone you know, but I'll do my best to answer your questions...

Mike (the tuner) said there was no knock and compression was good. You are correct assuming we did multiple runs, and it was actually worse to begin with. This is the best he could get it.
I'll have to ask him about getting the log, but I'm assuming if it was running lean he would have fixed that.