Stock head gasket limits. - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Inabj2 · 06-07-2012, 07:24 AM

Motor is closed and running 20.6 psi of boost on E85, on a road tune, that was done for a previous built motor. This motor was supposed to be a temporary motor, however this has been my temporary motor for over 2 years.

I went to a dyno day recently and it turned out my car made 455 almost 456 rwhp and almost 350 lb-ft. Seeing how I been at this power level for some time, And how fuel richens up a bit after 7,000 rpm I think there is room for more power if fuel leans just a bit up top, and perhaps find if timing is ideal or if it can be advanced even more.

I wonder has anyone done 500 rwhp or over in stock headgasket and bolts? I know for sure of one car with over 450 in my personal experience this has turned out to be reliable. But I can't help but feel that I may be pushing my luck, if I go further.

06-07-2012, 07:24 AM	#3
Inabj2 Join Date: Feb 2007 Location: Glendale Arizona Age: 41 Posts: 14 Trader Rating: (0) Feedback Score: 0 reviews	Motor is closed and running 20.6 psi of boost on E85, on a road tune, that was done for a previous built motor. This motor was supposed to be a temporary motor, however this has been my temporary motor for over 2 years. I went to a dyno day recently and it turned out my car made 455 almost 456 rwhp and almost 350 lb-ft. Seeing how I been at this power level for some time, And how fuel richens up a bit after 7,000 rpm I think there is room for more power if fuel leans just a bit up top, and perhaps find if timing is ideal or if it can be advanced even more. I wonder has anyone done 500 rwhp or over in stock headgasket and bolts? I know for sure of one car with over 450 in my personal experience this has turned out to be reliable. But I can't help but feel that I may be pushing my luck, if I go further.