I have a 97 GST with injen style intake and filter, upgraded to big 16g turbo, full 3" turbo back exhaust custom made(no cats)w/straight thru design magnaflow muffler, Apex Super AFCII, Greddy Profec Type S Boost controller. How much boost is available to run efficiently and how much should i run? Could i squeak out a high 11 or low 12 with what i have??

 

you will not hit a 12 with what you have. you need to upgrade your fuel system before you go turnning the boost up. you should get you a walbro fuel pump at least a 190 then some injectors 550 or 650 will be a good choice. and if you go with the 250 walbro, you will need a afpr. a front mount will help out alot.
with what you have right now i would keep the boost down to around 14-15psi until you get the fuel mods. thats were people make there mistake they get a turbo or a mbc turn the boost way up and wounder why there engines blow up. more air without the fuel to mix with it will cause a lean mix and thats when you start blowing things.

 

sorry, i forgot to add that i have a walbro 250 but not bigger injectors and no fuel pressure reg.. So i need to add those to those to the shopping list. By the way, it is a bitch to get the boost controller settings just right. Thanks for the info AWD!

 

yea if you have a 250 walbro you need a afpr first thing. it will over run your stock fpr. i just use a mbc to control the boost cheap but easy.

 

You will need the fmic to run full boost but you should be able to run around 21 PSI everday, if you have all the right mods.