i have a 1998 26 sonic with 502efi that has after market exhaust , k+n air filter, msd ignit, adj. fuel reg, ecu reprog. 24p bravo 1 running 68gps @ 4800 rpm wot. would like to run 80mph or close. looked into vortec super charger which i really like.my problem is i can only get 89octane fuel. was told that i could run a diff. pulley less boost and get 75hp instead of 150 hp with the pulley that gives 5-6 lbs boost vs the smaller pulley that gives 3.5-4lbs boost. is this really worth the $$ and gains or is there other choices to go to get me where i want that is cost effective and reliable? also what mods do i need to my engine for reliability ?

I think you could tune your engine to run on 89 octane and not give up as much HP as you think. I'l bet you could develop an extra 125 HP with 4 psi. You could also use a better intercooler and maybe get away with 6 psi. Send me an email or call me at (416) 709-8714. My intercooler setup for carb engines will be on sale soon and I'm looking for someone who would like to participate in the development of the EFI application.

I ran 89 octane in my procharged 502 when I had my Checkmate. I was running 5 lbs if boost. Ran fine to 3000 rpm. Above that it ran like crap. I don't know if it was detonating or what. I would not do it if 89 is all you can get, too risky.

sonic 26, get hold of Bob Endress at Vortech and tell him your problem and he will help you.

Consider M-3 Procharger package, it is designed to run with this octane at 5 lbs. boost.

Careful with any package on EFI, make sure the shop you work ith knows what they are doing.

With the right setup you can make the power needed.