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Discussion Starter · #1 ·
hey quick question,
how much boost (psi) can the stock turbo handle?

ie 22psi
 

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I would spike at ~20psi, maybe 20.5psi, but that's all i could get on pump gas. It would fall off to ~14psi by redline too, the tiny VF39 just can't push enough air at high rpm.
 

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Discussion Starter · #3 ·
thanks man
 

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After a certain point the vf39 its just inefficent at the higher boost... flame thrower city. My protune by Doug peaks at 20.1 psi.
 

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I'm at 21 psi tapering to 17
 

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soDo said:
I'm at 21 psi tapering to 19
You're still at 19 at redline? Gosh I hope your boost gauge is wrong ... I'm surprised the flames coming out of the VF39 don't melt the Y-pipe coupler... :D
 

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yes running a lot of boost on the stock sti turbo can blow the motor..
i know from experience.
there are a few on the forums here that say you can achieve 400 whp w/ stock turbo on leaded octane.. however i feel that the stock turbo only pushes so much.. in boulder CO more then a mile above altitude I made 290 whp and 325 wtq..
 

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dubrexer said:
yes running a lot of boost on the stock sti turbo can blow the motor..
i know from experience.
there are a few on the forums here that say you can achieve 400 whp w/ stock turbo on leaded octane.. however i feel that the stock turbo only pushes so much.. in boulder CO more then a mile above altitude I made 290 whp and 325 wtq..
I;ve never heard of anybody hitting 400whp on the stock turbo. The most i've heard of is like 340whp, and that's ALOT from a tiny vf39. And it's not boost that killed your motor, it was a bad tune or detonation. There are people running 30psi with a 35R on stock internals and they have lasted for 10K+ miles being abused, and those stock blocks are still running strong. I doubt 20psi out of a tiny vf39 is what blew your motor.
 

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yea, you can run the stock turbo to oblivion and as long as its tuned well it shouldn't hurt your motor at all. Running too much boost can be the culprit (once you start getting into really high psi) but from what ive seen its generally its due to problems with the afr's (read: the tune).
 

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Rootus said:
You're still at 19 at redline? Gosh I hope your boost gauge is wrong ... I'm surprised the flames coming out of the VF39 don't melt the Y-pipe coupler... :D
21 tapering to 17 I mean lol
 

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...I spike @ 21, havent had it no wear near redline yet....:D, so I cant say what it will hold.... Im still trying to get a grip on this boatload of power that I have now:eek: I keep letting off of it because it has definatly reached the "scare me" factor....:lol:
 

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Stage 2 here with eBay TMIC.

I'm ProTuned by PDX and I spike to 20-21 PSI and taper to 15 PSI. As long as your is tune good, you should be okay. Key is the tune. OTS Cobb map, I would be worried hitting above 18 PSI.
 

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no tuner worth their weight will ever try to run the stock turbo to "oblivion". Its a waste of time. The stocker is very limited in capability and starts to drop off after 18-19 psi....
 
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