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How much boost can a stock 2008 gt spec b handle.


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Hey everyone,

 

I have a electric boost controller that i want to install into the car, it is a 2008 gt spec b.

Was just wondering what is the highest boost i can run with the car being 100% stock besides 3" turbo back exhaust.

 

or is running more boost without a retune, just a really bad idea on this car ?

 

 

Cheers.

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Extremely bad idea. Sell your boost controller and get a protune.
I second this. These cars don't work that way. Your wallet and sanity will thank you for heeding this advice. You should also have a proper tune in the car for a 3" TBE, otherwise you will over boost (a bad thing) and your shit will be Ruinned.

 

The attached PDF "A Subie Newbie Tuning Guide" is a great place to start.http://cloud.tapatalk.com/s/5a97534b91403/ASubieNewbieTuningGuide1_0.pdf

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Thanks for the reply guys :).

I had a feeling that the subi wasn't like the skyline i have that i can just wind up the boost.

 

Would it be worth keeping a hold of it and using it when the car gets tuned ?? or are they not needed when getting them tuned ?

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When tuned properly, you will not need the electronic boost controller.

 

The answer to how much boost these cars can run is a convoluted answer.

 

On the factory tune, IIRC, 15psi was the max boost. There were people that cracked ring lands right from the factory. However, the factory tune was not very good.

 

I ran about 22psi on a factory block in my 07LGT with ~109,000 miles on it without issue. The car was tuned well, up to date on all of its maintenance, and also had all the supporting mods.

 

The key to both of the above is the tune. A bad tune will ruin a car under low PSI where as a good tune will protect it under higher boost levels.

 

With your current mods being only a 3" turbo back, I wouldn't exceed 18psi on pump gas. This is widely considered a "Stage 2" tune. If you start to go above that, the factory top mount intercooler becomes your weak point and starts to blow apart under the stress. Also, the factory turbo starts to become a hot air blower after that anyway.

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You can bullet proof the tmic to avoid the splitting issue.

 

Boost is thrown around alot but its not as much the boost pressure but what turbo and cfm's your pushing. Dsm crowd was always saying "I'm running 20 psi on a stock T25" and yet someone else is only running 18 psi on a big T28 from FP. Two completely different turbos and the T28 moves more cfm's then the T25 regardless of the difference in boost pressure.

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You can bullet proof the tmic to avoid the splitting issue.

 

Boost is thrown around alot but its not as much the boost pressure but what turbo and cfm's your pushing. Dsm crowd was always saying "I'm running 20 psi on a stock T25" and yet someone else is only running 18 psi on a big T28 from FP. Two completely different turbos and the T28 moves more cfm's then the T25 regardless of the difference in boost pressure.

 

That is only partially true. Manifold pressure is important and will help you determine your overall power setting...

 

Back to the original question. The Subarus have other things that I would consider more important to improve first before jumping straight to a manifold pressure increase. A little ECU work by a qualified individual would be far more beneficial in the long run, to subdue the effects of Subaru calibrating with emissions in mind.

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FWIW, 18PSI will split the TMIC.

 

I guess I was lucky then, the previous owner had the Spec B protuned and was running 18 PSI on S# with the stock intercooler. I am in no way suggesting the OP does so, my spec B is now configured 100% different from how the previous owner had, I'm just stating facts.

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