I have a 1990 Reatta

full exhaust
3" intake cone
Delco Ignition upgrade
RapidFire #14 plugs
Underdrive pulley
GM Tuners chip

I have had the car tuned but with a increase in WOT timing i am not getting any knock

Ryan at GM tuners says there is a possiblity to pass your peak performance and not get knock. I was wondering how many degrees advance you guyz were running in you cars

Ask Ryan to look at the figures he has on the Fastchips I sent him to get started on my turbo chip. The Fastchips had extra timing added beyond their normal premium fuel chip settings, as a matter of fact I sent it back and had more timing added twice. He sent me the timing chart for it but of course I can't find it now. It even worked well without knock on 93 octane after I had increased the compression ratio to 9.1:1. I think the figure is a lot more than 24*. I was also running a 160* thermostat, and it liked lots of timing. Ask him to look up Hal'* or 2seaters chip.

Yeah, I am the guy. The vin L pistons I used measured 30 cc in the dish. The original pistons were 26cc, but were .050" shorter compression height. The new pistons are flush with the deck to about .002" above. The reason I mentioned compression was the flame front travels faster with higher pressure, somewhat offset by higher octane fuel.

Before I got with the program to increase performance, I would sometimes see 1-2 degrees of knock retard at the shift points running 87 octane and the engine stock, save for a cone intake filter. I think GM did a pretty good job optimizing the stock setup.

I saw the comment about getting to the point of too much timing, and that is possible. The conventional wisdom is to set the timing to get the best trap speed rather than the quickest e.t., it is safer. You really need to experiment with what works best with a particular combination once you start modifying. Most aftermarket chips do offer some improvement, but will usually be safe, rather than optimized for your particular combination. Ryan is a good guy to work with and I recommend him highly.

I will ask him to look up the timing he used. also good info on the L27 pistons!!!

he said timing is around 3-4 degrees above stock