I've only put a few runs on my '93 Z since doing the head/cam/header/throttle body/ injector/etc, swap. The first time out I went a 12.69 @ 110 MPH with a 1.86 60 Ft. After it running so poorly, I started checking for a cause. One was a clogged fuel filter that made pressure drop to 29# at 6000 RPM's. Another was the lack of TPS voltage. It registered .19 V at idle and 3.6 V at WOT.
Both of them are fixed now, but I can't figure out why I'm pulling 4 degrees of timing out at 6200 RPM's. I ran a freeze frame data screen on it with my Snap-On scanner. When I hit 6200 RPM's (On the shift lite) for a 1-2 shift, I freeze the screen. The odd part is my computer is showing 7700 RPM's. I'm not recording any engine knock, either. Anyone got an ideas?

Frank

 

OK...Nobody has any ideas. What is "normal" timing advance at 6200 RPM's? I'm running 34 (retarded 4 degrees). So, if I fing out why I'm pulling 4 degrees, total would be 38 degrees. Doesn't that still sound low?

Frank

 

38@WOT is not low. That sounds pretty much on par with the stock program. If I'm not mistaken, my car called for 38 or 39 at WOT with the stock program. With my stroker, I've found 36 to be more ideal.

Was the car very hot when the runs were made? Perhaps very high IAT or CTS readings make the car dial back the timing even though you are not knocking...