Hi
My scan gauge is saying that im getting 30 psi of boost at this point my car really starts to complain, I think im getting pre detonation sounds like rocks in the motor and engine starts cutting out.
Im wondering if im actually building that much boost or are these not that accurate ?
the car has lv 2 tune ,one step colder plugs ,and 42 mm turbo with ebay intercooler and a diverter recirculator . 2007 S
thanks

 

My AP scanner has two different "Boost" readings, one for each MAP sensor. The MAP/T sensor reads absolute pressure --- atmosphere plus manifold. The manifold MAP sensor reads only manifold pressure / vacuum. Sounds like your reading of "30" is from the MAP/T sensor --- 14.7PSI (sea level) plus whatever your turbo is producing --- typically 15 - 16 PSI. Maybe browse your scanner for another boost source?

 

MAP = Manifold Absolute Pressure

OP: Do you know the difference between "Absolute" and "Gauge" pressures? If not, google is your friend.

 

Thank you both for your replies.
I was supose to get a instant email when somone replied to this post but I did not

 

If your getting that much detonation better get it fixed before it breaks a piston or rod. Who did the tune?