Quick chrome question:

[Twofastoocatch]

Hey guys,
I'm not sure if there's a problem or not, but here's what's going on.

1991 GTO. BPU/CAI/exhaust/Chrome are all that's really important.

After having issues making the car run half decent I found out my TPS wasn't quite tripping the idle switch. Re adjusted it, car runs awesome. So I took it to the track. I couldn't break into the 15's. I think 15.6 was the best I could do, and even that was at 92 mph.

Last time I went to the track I was consistently running 14.6-14.1 @98-101 mph, and the only thing I've changed was installing the flash ecu/Chrome. My question is, if I lost 9 mph, and well over a full second, is it my tune, or is it something else?

I haven't really played much with the timing maps (the little bit I have, has been advancing timing from 100 load on), not at all with any of the fuel maps, (other than the MAF smoothing table to get the fuel trims reasonable) but am I expecting to much from the factory 99 rom? Do I need to tweak it that much? Or should I be looking more seriously at something mechanical? Thanks for your time.

[jba3]

I might be stating the obvious, but boost leak test first?

Is it holding boost?

Can you log boost and see if it drops quickly after peaking?

Check timing advance, etc, from the logs.

Did you disable the EGR, etc, in the rom?

Switching to a flashable ECU, with an identical map, should have zero affect.