Not sure if this is an engine or drive train question. I'm running 15-17 PSI, 2'5" exhaust and fuel increased my car is 2.8.
On the motorway I see constant 7-10psi on flat road cruising along in 5h gear doing around 90-100kph, if I slightly accelerate it will boost to 15-17 psi until I ease off to keep a regular speed & boost hovers around 10psi. Its like its always loaded in 5th gear at highspeeds, I've had this problem with 31 inch wheels aswell. Could someone shed some light on this?