- Sep 15, 2017
- 2010 BMW 135i Single Turbo
21 psi at what RPM though? Because 21 psi at peak torque RPM will be a very different level of cylinder pressure than 21 psi at 7000 RPM. I think ignition advance will also likely play a role, even if only in peak pressure rather than average pressure. Do you have any more details on the cars that have had heads lift? Would love to have some data to try and tailor my tune for more longevity.No You will stretch the factory head bolts and lift the head of the block.
its not about the power level, its cylinder pressures and many have found out the hard way.
21psi is about as much as you want to run on a stock motor with stock head bolts.