I am trying to figure out what is an ideal compression ratio for boost. I am building a 2003 6.0 and am going to go .030 over . I am looking into forged pistons. Has anyone changed pistons? If so what brand?I am running 72cc heads. Stock crank ,LQ9 rods.

Thanks
Danny

 

That depends on how much boost you plan on running. If you plan on running over 10psi Diamond has a set of off the shelf pistons for you appl. that would put you right at 8.9:1 with stock thickness head gaskets. They are the same thing I am running. I prefer lower compression in case you plan on running more boost later. If you have a Radix on the other hand, 10psi is about all you are going to get out of it on a 364ci engine and 9.5:1 may be better suited for you. There are a lot of variables.
You will be looking for pistons that fit 6.098" rod with .945" wrist pin and 3.62 stroke. I have 4.000" bore which is diamond #11514. 4.030" is #11515. They show in their catalog that the 11515 is a .927 wrist pin but that has to be a typo since the .927 wrist pins are for the old sbc's 6.125" long rod that you can use in these engines, and the compression height of the piston is the same as the .945 #11514. Anyhow, you can view their catalog online @ diamondracing.com and Texas speed and Thunder racing both carry diamond.
JE & Mahle also have a good selection of gen3 pistons.

 

I am looking at the Magnacharger with max of 10 psi. Thanks for the reply and link.

 

I would suggest nothing less than 9.5:1, once you get into the lower compression motors the bottom end of your power band suffers IMO.

 

I agree with high compression with the Radix or any other system that you dont want to spin too high.

Im currently running about 10.8:1 with my Radix and making pretty good power on the 3.70 pulley. We will be dynoing it next week to see what its going to max out at on 5psi. Later on I'll try 7-8psi.