I usually find everything by searching, but here's a question for you guys. I am running my Turbo'd GS this coming Saturday and wanted to raise the boost past 15psi with 100 octane. I don't have timing control as I am on Hahn's PF. My afrs vary from 11.2 to 11.8 to redline (leanest I go is close to redline, trying to fix this). So, can I raise the boost to 20psi with race gas? Or should I go only 18psi? I just have never tried it before and was looking for some input. I've been running 15psi for about a year now and haven't gone over. I want to get the MSD box with boost retard very soon. Here's a list of my mods done to the car. BTW, I love this site, so much info.... and funny stuff to read as well.

Built bottom end, JE 8.8:1, Eagle rods, Unorthodox UDP, Ported head, 60mm throttle body, Ported intake mani, Custom Spec 3 clutch, Eibach Ground Control with AGX struts, Cheater slicks. Hahn super 16g turbo and log mani, Hahn FMIC, Hahn Port Fueler, Innovate LC-1 WB02, 3" TBE.

i say go for it and listen for knock. trial n' error.

Originally posted by 420agreenvilleSC
i say go for it and listen for knock. trial n' error.

In all honesty, I've always had pretty conservative on AFR and don't even know what knock sounds like. I don't think I've ever heard knock. I think if I can get a tune to stick right at around 11.2 to redline I'll do 20psi, if not, maybe just sport 18ish.

Do you have an EGT gauge? Its not just AFR that you need to keep an eye on, esp when your running stock ignition timing. Do you have adjustable cam gears?

Originally posted by Slo2g
Do you have an EGT gauge? Its not just AFR that you need to keep an eye on, esp when your running stock ignition timing. Do you have adjustable cam gears?

No EGT gauge and no adjustable cam gears. I am getting a Zeitronix system soon though, with Booast sensor, EGT, AFR.

I wouldn't risk it. If you do decide to try it then I would do it in VERY slow fashion. Only up the boost a little per time and monitor you spark plugs in between each run. I would only do it if you have access to some type of data logger that way you know exactly what your car is doing. But if you want to try the "trial and error" method you can and just do it, but if you do have the bad side of the trial and error then you could be rebuilding again. Just ask Mikey :P

if you don't have the time & you're not financially prepared, i wouldn't do it. not worth it.

Nice sig mikey :p

Originally posted by Slo2g
Nice sig mikey :p

rofl

I think I'm just going to keep it at 15psi since some knock at that boost level. But I will be running 100 octane since I'll be racing for extra insurance. :) Thanks