I've got a '90 TII and I was wondering what's the highest PSI I can safely run on a mostly stock setup. I have a 3" Magnaflow catback, K&N intake, rebuilt/flowtested injectors, and a somewhat recent rebuild. I know the old Datsun 280ZX turbos could safely run 10psi without even an intercooler so I was just curious. Of course they also have pistons, so it may not be a good example. I was thinking of just getting an MBC and tweaking it up a little for now. What do you think?

 

with that exhaust i would see if you have boost creep. witch means death for your motor. If you're looking for more boost then you'll need a fuel cut defender (fuel cut is at 8.5lbs i belive, don't quote me on that) a ported wastegate will help boost creep. hopefully that helps get you started.

 

yes, absolutely an FCD will be required for turning up the boost, with that setup on an S5 you are probably already around what, 8psi? (do you even have a boost gauge that isn't the stocker?)

Anyways the most you should safely run with the stock fuel setup and TMIC would be 10-11psi...

 

10-11, good. I have an aftermarket boost guage and it maxes at 6.5 psi. I should look into an FCD, and I definitely need an AFC to tune the A/F ratio because at present it's extremely rich.