Hey guys, I was just wondering how much PSI we can boost without an intercooler with the following turbos

T61
TO4
GT35

Thanks guys. Oh yeah with stock headgasket.

 

-1 psi. or a hole in your piston.

 

why would you upgrade to a single turbo and not add a intercoooler?

with those turbos especially, and our engines too, you NEED a intercooler, hot air going into an engine is never good, specialyl after it's been compressed by a turbo

 

respectfully disagree. compression temperature is not a linear function. The heat input at 4 psi is not half the heat input of 8 psi, etc. Corky Bell has an excellent book about turbocharging basics (Maximum Boost) that is worth a read by everybody. He states that, as a rule of thumb, at 6 psi and under there is not enough density recovery to overcome the frictional losses of the I/C, and the heat input isn't enough to warrant detonation concerns.

 

Hrm.. I'll answer the easy way, but I'll let you figure out why you don't want to do this

10-11 PSI on any of them turbos on 91 will probably be ok, but that assuming you have 8.5:1 compression engine is healthy and yada yada yada.

like I said figure it out... ask a bad question get a bad answer

 

I know that its not a good idea to run boost without an intercooler, but there are acceptable PSI levels for boost. Thats why greddy and other company's sell turbo kits without Intercoolers. I was just wondering How much 2jz-ge's could handle without blowing up and still staying healthy.

 

I would have to agree with this. At 6 psi or less, you're only adding a half an atmosphere. The pressure drop with an intercooling system effectively lowers the boost, but you're not really compressing the air enough to make THAT much of a difference in heat. So, with an intercooler, you end up turning up the boost to compensate for this pressure drop. You start to chase yourself to some extent.

A buddy of mine ran a Vortech V-5 on his 2.0 liter 8-valve Jetta for years with no intercooler - just a nice, short shot to the throttle body (about 7 inches). With a simple fuel pressure regulator and about 6 pounds of boost, that car ran pretty darned well - well enough to take down VR6 powered VWs easily!

Would love to see an NA 2J with a nice short intake tract to the throttle body and about 5 pounds of boost. It wouldn't be a beast, but it would be responsive- exactly what these cars need!

 

i suppose, i forgot about the american's only getting the GS version of the engine. hence why i said conversion, cause i assumed going from twins to single turbo.

i'm not framiliar with the GE version of the engine, as compression and everything is different. i'm sure if your only going to run about 5 psi on the engine, you'll be fine without an IC.