[TwoTonedRoush]

I bought a 01 cobra motor for my gt and I was wondering if the compression ratio for the pistons is that same as the 03 and 04 supercharged cobras. If you know the comp ratios that would be great. Also how much boost can your run on those motors, I ran 8psi on my 4.6 sohc and thats about max on those. I'de like to know so I don't blow this motor like I blew my gt motor....

[Steel City]

Originally Posted by TwoTonedRoush

I bought a 01 cobra motor for my gt and I was wondering if the compression ratio for the pistons is that same as the 03 and 04 supercharged cobras. If you know the comp ratios that would be great. Also how much boost can your run on those motors, I ran 8psi on my 4.6 sohc and thats about max on those. I'de like to know so I don't blow this motor like I blew my gt motor....

the compression ratios are different between them but im not positive on the exact numbers so i'll leave it at that. as far as boost goes on the earlier n/a cobra motors....your pushing it @ 10lbs of boost. if you run a 10lb pulley setup make sure you have some good midlength or long tube headers to keep the boost down and get heat out of the motor

[TorchRedGT02]

Compression ratio:

03/04 Cobra: 8.5:1
01 Cobra: 9.85:1

[JD04COBRA]

Originally Posted by TorchRedGT02

Compression ratio:

03/04 Cobra: 8.5:1
01 Cobra: 9.85:1

You beat me to the punch. I agree with the 8-10 psi. Seeing how the 99-01 motors don't have forged internals and the 03-04 motors do. If you plan on running high boost, I would invest in some forged rods, pistons, and crank. It would be a worth while invest.

Wait a minute didn't you say your gt was already supercharged, my bad. You already know about the need for forged internals. Sorry, my brain isn't working so good today.