Does anyone know what boost pressure (psi) the supercharger puts out on the 2007-2009 4.2l S/C engines?

Thank you

 

Anyone?

 

I don't think you're being ignored... I suspect that no one (that has seen this thread yet) knows. The 5.0 Supercharged will do up to 11.6 lbs of boost from what I understand.

 

Thanks Rahtok, I think I might get REV for the iphone and try to get an accurate read. I have the 4.2l XKR which maybe 11.6 as well but could be higher, lower or differnet from car to car by a fraction. Hopefully it can read boost from the OBD.

 

Did you ever find the answer to this? I was out in my own 4.2 XKR tonight with an app called Torque running and it showed 11.5psi peak boost, 3rd gear close to the red line. I'm just interested to find out if that's about right.

 

You won't get an accurate boost measurement via torque app.

The map sensor on the 4.2 is mounted in between the throttle body and the supercharger, so it does not directly measure boost. At best you get an estimation based on the change of vacuum at the tb.

If you want a precise measurement you'll have to fit a gauge, .

 

Starting with the caveat: I have a 2003 XKR but I think the 4.2 is the same between them, at least with respect to the S/C system and pulley sizes.

Before I took the Eaton off I would see ~13psi. With the water injection on it would go up a little to an all time high of about 15psi.

This is measured with a boost gauge connected at the S/C outlet and at an altitude of about 1200ft in the dry desert of Phoenix.

 

I recall looking into this a while ago..... on the Eaton web site, if memory serves, 13.6psi was the max. it took a bit of digging.....

 

I have seen both 13.5 psi and 11.6 psi posted so there is some confusion.
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Well, this answers my question from another thread. Looks like I need to add a sensor.