How do you figure out how much boost you should run in your car? how do you know what your max psi would be?
i have a n/a car but i am looking to buy this car that is turbo charged, and i dont know enough about turbos, so can some people school my ass on this shit? thanx in advance

 

we need info on the car first...

 

ok heres he specs on the cr hes takin about

1995 Saturn SL2 Turbo
Engine: 1997 1.9L DOHC - JE 8.5:1 pistons, Crower forged rods, ported head, '91 valves and springs, custom grind cam profile, Garrett T3/T04 hybrid turbo, manifold and downpipe from Thomas Knight, custom spearco front mount intercooler and aluminum piping, HKS blow-off valve, Cartech boost-dependent fuel pressure regulator

 

the thing most people don't understand about turbos is PSI doesn't really mean shit.

a small turbo running at 20psi will flow less than a large turbo at 10.
Keeping that in mind...a t3/t04 is about the most common turbo there is. But the specs on them can vary so widely, that saying you have a t3/t04 is pretty worthless when you're trying to give people information on your car/turbo.

Next on the list...how about fuel?

Please read some information on turbos on the internet.

 

ah, but engine size does.....

a small turbo may be capable of spinning up 30psi... but not on a larger cid engine....

a small turbo on a larger engine may be capable of only 4psi, where it was capable of 15psi on a smaller engine...

also, keeping in mind.... cnc'ing the heads, bigger valves, camshaft duration and overlap, low restriction exhaust system
all play a role in just how much boost you will see....

2cents........

 

Stole the words from my mouth.
How Stuff Works - Turbos

 

heres my easier, less confusing input, my compression is 9:2:1,my motor is completely stock except for my dope ass gold valve cover,i can boost to around 15 psi with the bigger injectors i have right now, with lower compression you can boost 15 psi and not make as much or about the same power on the same motor, if your compression is low, higher psi(more or less) higher compression, less psi, if were talking about stock blocks here(honda block mind you, i dont want to here about you 20 psi dsm fuckers), but considering what is done to that saturn motor with upgraded pistons and rods, you could prolly boost a hefty amount with the right amount of fuel and tuning, the compression is low but with the machined head and most likely bigger valves its going to flow more air therefore also causing a boost predicament, like i said, i have a t3/to4e turbo on my car and on race gas i feel comfortable running 15psi with my stock motor, i would just have to assume that the turbo is a regular t3/to4b or E, not alot of difference anyway unless your trying to get into some complicated shit, hell with whats done to that motor, now i dont know saturn blocks, but you should be completely fine running 12 psi everyday with a good fuel pump and injectors, shit, i ran 12psi on stock injectors and never hurt my car, take it how you want, but i would boost the shit out of the planetary creation of a car.........but thats just me, i could be wrong.......

 

well... ive got a saturn too and i just ordered a turbo kit for it .... saturn stock interals can only hold 6psi with an upgraded fpr. If i were to get 36cc injectors and tune her up a lil bit .... i can get 9psi ... and thats it for my internals....

a set of 720cc fuel injectors with a Haltech engine management system will enable the saturn listed above to run rite at/or a little bit higher than 25psi with what it has.

juss to give u an idea of what the saturn engine is like ...

 

You're talkin a GOOD $2000+ though for the injectors, Haltech, install and tuning.

 

with the FMIC, i say 20 is gonna be the max or so you'll be able to run on pump gas.. your engine sounds pretty strong so it should be able to take the boost. to run high boost on that thing you really will want a good engine management system so that you dont' blow that expensive engine.. keep the EGTs down, the knock down, and good timing, and you're all good.. jsut start easy and work up to the edge.. a little while on a dyno would be nice too.