Join Date: Jan 2006
Location: Barrington Hills, IL
The coolant passages are used to cool the bearings on the turbo, Id
personally recommend at least running oil through those. As far as the GT30 being rated to 500HP, boost threshold on the turbo becomes far more apparent on a high liter car. For example, here at our shop we can run 30psi through the GT30R, at that point it stops making power on our 2.0 liter motors. On a Porsche motor, the T3 hotside would be way to restrictive even at 1.0bar of boost. There are just too many liters to fill will such a small cfm rating.