What is a safe level for boost?

I was wondering if anyone knows what is a safe boost level on a stock EJ257 W/ stock turbo? I heard everything from 22-29 PSI, I just want to settle this once and for all!

THANKS!!!

I'm no pro when it comes to that, but factory is 14.5 psi. A safe tune is around 19-20, but I will let masterminds explain!

Fujiwara said:

Likewise, the reason why I personally will not push an OEM IHI turbo past 19 psi at redline has nothing to do with the compressor efficiency. The real reason why most stock turbo tunes have tapered boost at the end is the fact that the stock turbo isn't properly balanced to push much more than 19psi at peak flow -- past that point you will over spin the turbo past the balance point -- if you don't believe me -- look around for guys who have blown turbos on a 21 psi tune with a Hallman MBC.

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From the master

Fuji's explanation is the best...
...and consider this.

Back in the day when I was on the stock VF39, my tune was set at 20.5 psi at
peak (I can't remember right now what RPM that was but somewhere around 3800?)
and then it tapered off.

However, after reading Fuji's post, it makes me wonder if this was why I eventually
cracked the hot side of that turbo on the wastegate housing.

Food for thought :tup:

Batmobile_Engage said:

Fuji's explanation is the best...
...and consider this.

Back in the day when I was on the stock VF39, my tune was set at 20.5 psi at
peak (I can't remember right now what RPM that was but somewhere around 3800?)
and then it tapered off.

However, after reading Fuji's post, it makes me wonder if this was why I eventually
cracked the hot side of that turbo on the wastegate housing.

Food for thought :tup:

Click to expand...

I believe the cracking of the hot side to be a materials and/or casting problem. This is common in those turbos even when running stock boost levels. Plus boost wouldn't cause that to happen.

It's not power that kills them, it's poor or aggressive tuning, poor build quality, poor maintenance, and other reasons.

Spamby said:

I believe the cracking of the hot side to be a materials and/or casting problem. This is common in those turbos even when running stock boost levels. Plus boost wouldn't cause that to happen.

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I knew that other people have had the same issue, idk why but I guess I figured maybe more boost meant more heat in the turbo and higher EGTs, so if the turbo was prone to failure anyway, pushing my luck may have been the last straw so to speak.

Fujiwara said:

Running the stock turbo too hard will end up destroying the bearings and or seals for the center cartridges of stock IHI turbos. Once they have been properly balanced you can spin the turbo much further.

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I had a slight oil leak from the turbo as well. Not while installed, but after removing it, a crack was visible that had opened up and it drooled a little bit of oil.

I bought the car used, though almost totally stock. Who knows how bad the previous owner beat on the car?

My bad, getting a little OT.

Fujiwara said:

Running the stock turbo too hard will end up destroying the bearings and or seals for the center cartridges of stock IHI turbos. Once they have been properly balanced you can spin the turbo much further.

Click to expand...

Now how would one balance a turbo? This is news to me!!