Stock turbo psi.

[alhope34]

Simple question... Does anyone know what PSI the stock turbo produces?

[PlatMS6]

15.6 I believe...

[alhope34]

Holy jeebus. I was expecting 7-8psi. Thanks for the help. I thought even the STi ran 12psi stock. When I was working at toyota one of the mechanics has an '04 WRX and said he put an STi turbo in it which upped the boost to 12.5 psi with ecu re-mapping.

[PlatMS6]

We have a small snail...

[Garu]

I think tiny would be more appropriate.

[Unoriginalusername]

big or small doesn't matter does it as 12 psi is 12 psi... a larger turbo could spool more

[DCYT]

Actually, on my disi, it would spike to 20psi around 2500 - 3000 rpm
Then slowly settle down to 15psi around 6000 rpm

[alhope34]

20psi is really decent. Someone told me before that a 911 Turbo makes 21psi. It probably has higher psi at lower rpm because the engine cannot use all the air the turbo is boosting at the lower rpm, but the turbo is at full boost already. That's my theory, anyway.

[spd frk]

You guys are all confused about boost vs. power. Boost (12psi or 200psi) is a measure of work. it is easier to think of it as pressure ratio 12psi is 12psi above ambient (14psi) or a pressure ratio of 1.85:1 (26/12). psi in a small turbo like ours is not the same as in a large turbo like an STI or 911 turbo. Because they are larger and move more cubic feet per minute of air. The pressure increase results in an incrementally larger effect.

All that aside I think our stock boost target is 15.6psi. However this can change dependant on outside air pressure and temperature. When the outside air is thinner (high altitude) or hotter (less dense with oxygen) the ECU will increase the boost target a little bit to try and maintain the same power levels.

Consider this thread back from the dead ;)

[Wild Weasel]

That doesn't make sense to me.

I agree with the above... 12 psi is 12 psi. It's the pressure of the air in the intake. If it can sustain 12psi as fast as the engine can consume it, then the size of the turbo is irrelevant.

It would be different if it spiked to 12psi while the throttle was closed and then dropped to 10 or something, unable to keep up with the demand, but that's not the case, right?

[spd frk]

Sorry maybe I wasn't being to clear (I do that). I agree that 12psi is 12psi, it is the pressure in the intake manifold. But it is the pressure above ambient. I am just commenting in regards to people saying wow we push 20psi spikes and a 911turbo pushes only 21psi. That is an irrelevant comment.

the MS3 has a tiny little turbo, that can operate a 20psi (a pressure ratio of 2.4:1) but it can't flow much air at that ratio, because it is so small. A 911turbo uses a much larger turbo that at 20psi can flow way more air than the MS3 and probably more efficiently (less heat created through compression).

[Wild Weasel]

Right. To keep 20 psi in the intake of a 911 takes a bigger turbo because it's a larger displacement engine so it consumes more air.

And you're also right about the temperatures. Having a larger turbo that can supply the same pressure at lower RPM's producing less heat is definitely an advantage... so long as you don't trade off spool-up time for it.

[AutoXRacer]

Simple question... Does anyone know what PSI the stock turbo produces?

15.6 at stock levels.

[alhope34]

15.6 at stock levels.

Yes, that got answered November 4th, 2007. Thanks though. And I am no longer a noob with this car, lol.

[Unoriginalusername]

Yes, that got answered November 4th, 2007. Thanks though. And I am no longer a noob with this car, lol.

Hey Autox is a good member from another site that I pointed here play nice :chuckle

[alhope34]

Hey Autox is a good member from another site that I pointed here play nice :chuckle

Yea yea, I was just playing around :chuckle

[AutoXRacer]

Yes, that got answered November 4th, 2007. Thanks though. And I am no longer a noob with this car, lol.

Yeah, I noticed that after I posted. I got post happy since my registration just got activated... Sorry.:blush

Hey, how come all the threads have cobbwebs on them? :chuckle I was looking for questions to answer and they are all old threads... :pop


:)

[AutoXRacer]

:blush Damn, I just noticed its dated of last year...:blush

:gone

[Unoriginalusername]

Yeah, I noticed that after I posted. I got post happy since my registration just got activated... Sorry.:blush

Hey, how come all the threads have cobbwebs on them? :chuckle I was looking for questions to answer and they are all old threads... :pop


:)

we're canadians... when the snow melts for the 5.3 weeks of the year we all go outside instead of posting online :chuckle

[dread1]

psi is the resitance to flow i can have 35psi and only flow 200cfm
what you want is an increase of cfm psi is just an arbitrary number.
you can have 10psi and flow 200cfm as well. its all about proper turbosizing for your application. a/r and trims etc.
the ms3 turbo is probalu geared more towards civility rather then all balls out power. i.e. reduce lag, and realiability.

Just my .02 cents and putting it in simple terms

[Broxn]

Sorry...not "jacking thread"
Unoriginalusername- love the sig....

[Unoriginalusername]

Sorry...not "jacking thread"
Unoriginalusername- love the sig....

mazdabetty did it

[Scottobot]

Sorry...not "jacking thread"
Unoriginalusername- love the sig....

+1, for the record