[8_6_Fo_Life]

Originally Posted by Jeff240sx

I'd also look into timing. I don't know what sr motors run, but there are a few reasons for the lumpyness of the curve, and timing is one of them.

That is quite true. Normally on dyno graphs, those wiggles and jumps usually translates that the car wants MORE timing. But, just yesterday we checked the timing on his car and it was on dead-nuts 15*. Personally I dont know enough about the SR20DET to reccommend any more timing then that, even on stock boost.

Or ignition, as in fouled plugs, ect. Was the car breaking up on the dyno? Bad gas?

There could be some sort of ignition problem, but I doubt it. It has never broken up on the street, nor on the dyno. The car never stumbles or misses...its just weak. There is no guarantee, but I dont believe he had bad gas. There was NO pinging present, and it has never pinged before.

One other thing I'm fairly worried about are your a/fs. They're very lean up to 4400 rpm. Very lean.

This was concerning us as well. The car is making full boost I would say around 3000rpms if not sooner. I would like to see the car pegged at the 12.5-12.8:1 line from there to redline, but as you can see it stays lean until 4,400 for some reason. Its running a stock SR computer, nothing else (no piggy back/afc). I would have to assume that with stock boost levels and practically no go-fast bolt ons it should be plenty to have the car running right. I am almost leaning towards a bad stock fuel pressure regulator. In the past I have seen a few cars on the dyno with bad FPR's create a similar A/F reading. Thoughts?

Then again.. what the hell am I? An armchair dyno specialist?
-Jeff

Ha, Mike and I appreciate the help...we need it. Plus I am a dyno specialist, so I need to learn how to tune SR's for the future. This one has me stumped.

8_6_Fo_Life -