max boost?

[turbota633]

what is the limiting factor on how much boost you can put through an engine? can a stock 3.8 block only handle up to so much boost? ENGINE KNOCK ASIDE, Thanks in advance

 

[441120]

boost

Knock is the limiting factor,to a point. Cylinder pressure, charge temp, octane, timing, head gasket strength, head bolt/stud quality/torque etc all play a part. Have heard stock long block properly tuned, 116 octane, alky, good air,etc...30# boost!
I'd only try it if I had time to fix what I just left on the pavement
Start low and work your way up..Remember...Knock=$$$$$

 

[Ormand]

If you control the knock, the next thing that will bite you will be the weak bottom end. Once you get to 600 horsepower, you need the girdle to support the crank. Even at 500, the girdle would be good insurance.

 

[Nojug]

In my street car I have ran 32 psi on the stock longblock with no knock C16 and a Red Armstrong 93 octane chip with like 23 degrees of timing. That is with a completley stock never been apart 80,000 mile short block. The car weighs 3760 with me in it and has gone 127 so its making like 650 at the flywheel.

 

[azgn]

boost is not the determining factor on engine longevity....it is how much cylinder pressure/power that boost is producing

ie 30 lbs of boost on a stock headed car isn't gonna produce much power

at power levels above 500 hp (or so), a stock long block is at risk(it was designed for 250 HP.....) this could happen at 15 lbs of boost with efficient heads and turbo or 30 lbs of boost with less efficient heads/turbo

with no detonation, the motor will stay together longer, but something is going to give eventually if you are making big power with a stock block and internals