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I was curious what boost levels people are getting with their stock '04s.

More specifically, at what RPM do you see max boost.

I just passed the 1000 mile mark, so I'll be gradually working away from the 4000 RPM limit. :D I've taken it to ~5000 RPM in the 1st three gears, and the max boost level I've seen is about 0.05MPa (stock turbo gauge), or roughly 7.25 psi. This is not pedal to the floor, but more like 1/2 to 3/4 throttle.

From what I understand, full boost is around 15 psi, or 0.1Mpa. Is this correct? And at what RPM can I expect to see this in each gear? At what throttle setting?

Sorry for so many questions.

Thanks in advance.
 

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Max boost on 04

From my experience and what i've read on the board for a low milage 04 even in 3/4 th gear you're only going to see about 11.5 lbs of boost max. I am not sure if this is a product of a low milage engine and a new turbo that hasn't quite opened up or not. In lower gears that number will be even lower. The max boost for first gear is capped at 9 lbs I believe so you wouldn't see anything above that. The factory cap is 13.5 lbs if I remember correctly for top gears. I've never run fast enough to check boost in 5th.

I seem to see it hitting 10 psi a lot when I hit it hard and thats about the cap that I'm seeing. I will say its really hard for me to keep an eye on my psi and my revs at the same time even though I largely do it by ear. Today I will try to get some low gear measurements for you. I'm currently at 6k mile on my car for what its worth.

Hope that helps.

Para
 

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I don't think there is a cap n psi in first gear or any one gear... Pretty much works like this with any turbo. The lower the gear, the higher rpm you will see full boost at, if you see it at all. Usually if you go from a stop, and pop it through a few gears, you will see full boost in second gear on most wrx's. If you wanna see how high the boost goes, pop it into fourth at 3000rpm and push the throttle down. The boost should go up pretty quick at that rpm in 4th gear.... The reason people see more boost in higher gears is cause there is more load so there are hotter exhaust gasses, and it takes a lot more time to get through the gear, so there is more time for the turbo to overcome the air needs of the engine. This is just from what I know:).

peace
 
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