1jzgte overboosting with free flowing exhaust

[queenskid926]

Taken from a writeup of the 2jzgte here on Supramania

"To raise boost beyond the stock level the catalytic converters are removed, this allows the turbos to spin faster and hence produce more boost.. The Downside with this is the JDM turbos will in fact over boost far past their safe limit and reach over 1.6bar (23.2psi). The small size of the JDM wastegate cannot cope with the increase in exhaust gasses and is held back. At these pressures the ceramic blades in the turbo can become detached from the shaft and therefore cause failure of the turbo."

I know the jdm 2jzgte and 1jzgte have the same turbos. I plan on going 1jz soon and wanted to know if i ran an open exhaust, no cats, will i run into the same problem?

I'm going to assume the answer to that is yes and My next question is will a boost controller prevent that from happening?

 

[The Reaper]

first off: 2J and 1J do not have the same turbos

and no a boost controller will not help prevent it. you can't run lower boost levels than stock WG runs. i didn't have too much trouble with a 3 inch exhaust no cats no resonator from the stock y-pipe back. just get an SAFC or a BCC

 

[Big Wang Bandit]

I never had a problem with my car. 3 inch exhaust no cat and just a muffler.

 

[annoyingrob]

I find it varies from motor to motor on 1JZs, depending on the condition.

A divorced y-pipe will give you a bunch, but just intake and 3" exhaust shouldn't give you much if any boost creep. If it does creep, it stays under 14psi. If it does hit about 14.5psi, the ECU will stop it from going any higher.

If you ARE having problems with it, taking a die grinder to the turbos, and porting the wastegates works.

 

[Ma70.Ent]

Porting the wastegate solves.

 

[queenskid926]

Thanks you all for the information.