Hey guys I'm long at upping the boost on the sti. ECU is defeniatly next on the list of mods but i was wondering if its ok to up the boost much on the standard ecu? I've upgraded to a walbro 255 pump.

I did a search and all I came up with was a page that said standard boost on 03sti is 10psi and highest safe is 16.5psi but I highly doubt that is on a standard ecu.

I also understand it might not be worth upping the boost yet/to risky on the motor in which case I wont bother.

Just wanting to hear from some people who have experimented with there sti and how it went.

You sure it's only 10? I'd say closer to 16psi in stock form.

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Beaten up old 98 Gen 2 Liberty, 13.0, stock V3 STI running gear.
07 Transit motor home
69 VF & 70 VG Valiants needing full restoration
Yamaha Zooma 50cc rocket hopefully going with the Transit.

16 psi.. tapers

The standard tune on 03-05 STi targets a peak boost pressure of 16.4 psi.

There are plenty of guys on this forum who have run in excess of 20 psi on the stock ECU without any issues.
Just make sure that this is done through a retune not through a manual boost controller!!

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MY99 WRX (Sold)
MY06 WRX 241hp 430nm atw (Sold)
MY09 BMW 135i 247kw atw (Current)

ok thanks for the help. Seems pretty high for standard boost and the details i found were pretty confusing.

Not high for an EJ207! Finish off that exhaust and get the car to ASG asap

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MY99 WRX (Sold)
MY06 WRX 241hp 430nm atw (Sold)
MY09 BMW 135i 247kw atw (Current)