HI i was wondering what the mazimum amount of safe boost is on pump gas. Does it vary from car to car? I'm running a t-78 and have upgraded just about everything, see my signature, for specifics. Just wondering what the max boost i can run with my current setup on 93 octane pump gas, without worrying about detonation.

 

My best guess would probably be anything under 20psi and anything above it you are asking for detonation.

 

20 is a little too much on pump gas, IMO.

on 93 pump, even with very good tuning, i wouldnt push it past 17 PSI. anything more than that is just asking for trouble.

 

I dont care how much boost you run, ALWAYS worry about detonation, you can detonate at 1psi , but seriously, run 15-17 psi, and turn it down a bit in the colder weather.
Rob

 

thanks for the info guys. special thanks to gordon, i appreciate you taking to the time to supply all that info, it was a big help. Any other opinions are appreciated, and yes i am running stock 550 primaries.
THanks again-
-Rob

 

I've been running 18psi on pump gas for quite a while now with no problems. Its all about tuning and air fuel ratios.

 

with 1200cc secondaries i wouldnt push 15-6psi
ive seen people with 1600's only run 18 max on pump94


but with pfc youllneed new map to run over 17psi,

gordon-well said man

 

My advice is to keep on increasing boost until your engine blows, then back off 1 or 2 psi.

 

doesn't sound like very good advice.

 

My car used to detonate at anything over about 5" of vacuum!! (rough guesstimation)

Tuning, no matter how bad, or good, combined with your porting etc., is the key,