FarmerMagnum
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I'm no master of the Stinger engine but I have built many turbocharged engines in my day and I'd like to offer a tip here. Boost pressure does not lift heads - cylinder pressure does. Cylinder pressure and torque are basically the same thing as the higher the cylinder pressure, the harder the piston is being pushed down. The problem is, the head is getting pushed up just as hard as the piston is getting pushed down. It would be nice to identify the torque levels people are hitting when their head bolts start yeilding and the heads start lifting. That way if we don't want to put head studs in - we just stay a note below that level.
Boost pressure is just the amount of air left in the intake after the intake valve closes - 18psi, 25psi, it doesn't matter. Boost definitely does not directly correlate with cylinder pressure or torque. That's why these ecu tuners can make widely different power levels at the same boost levels. However, if 600lb/ft lifts the heads - there's not much that can be done about that electronically. It's a mechanical problem. That's just the leverage required to stretch those bolts.
I suspect we're exceptionally susceptible to this because our engines are torque monsters. Honestly for a 3.3 this thing makes an amazing amount of torque. Moving the power up the RPM band would allow for more horsepower at the same or lower max torque levels but that might require alot more mechanical work than head studs.
Also replacing the head bolts with studs sometimes doesn't completely solve the problem. If you stop the head from lifting you're just going to trying to push the crank harder, bend the rods more etc.
The other thing that will blow head gaskets is detonation. Among other nasty things it causes big spikes in cylinder pressure and can pop head gaskets really quick. Our cars seem to have a really nice knock monitoring and timing control system though.
Boost pressure is just the amount of air left in the intake after the intake valve closes - 18psi, 25psi, it doesn't matter. Boost definitely does not directly correlate with cylinder pressure or torque. That's why these ecu tuners can make widely different power levels at the same boost levels. However, if 600lb/ft lifts the heads - there's not much that can be done about that electronically. It's a mechanical problem. That's just the leverage required to stretch those bolts.
I suspect we're exceptionally susceptible to this because our engines are torque monsters. Honestly for a 3.3 this thing makes an amazing amount of torque. Moving the power up the RPM band would allow for more horsepower at the same or lower max torque levels but that might require alot more mechanical work than head studs.
Also replacing the head bolts with studs sometimes doesn't completely solve the problem. If you stop the head from lifting you're just going to trying to push the crank harder, bend the rods more etc.
The other thing that will blow head gaskets is detonation. Among other nasty things it causes big spikes in cylinder pressure and can pop head gaskets really quick. Our cars seem to have a really nice knock monitoring and timing control system though.
