A friend of mine took a ride in my truck the other day and mentioned that he was going to supercharge his truck. He asked me to find out from you guys what compression ratio should he start out with on motor he is gonna build. He will be using either P1 or D1 and 12 to 15 lbs of boost. This truck will be running pump gas only he said as it is a street truck like mine. So what's a good number to start with? Thanks.

 

Talked to my friend today about compression ratio. Told him my 4.6 was 8.4:1 (per troyer) and I thought it was too low unless you were going high boost, which he is not. He also has a 4.6 motor and if he basically did what was done to my motor he could see 450 rwhp at best. Personally I would go higher on comp ratio to get more hp I told him. With limits of belt traction on truck setup with procharger, wouldn't the extra compression raise his hp numbers? I did tell him that if he switched to a 5.4 he would surely beat the Hell out of 450 rwhp. I sure wish I would have.

 

Crash.....Troyer had total say on how motor was built and who built it. I had nothing to do with it except paying for it. Yes compression is 8.4:1 on motor he had built for my truck. that's one reason that I don't see better numbers I guess. Fuel pump and injectors are now maxxing out at about 5000 rpms so that is where rev limiter is set. I had been told by others that compression was too low in my motor for street use on pump gas. Don't have any idea why troyer had it built like that especially going into a truck. Main thing is I didn't want to steer my friend in the wrong direction on motor like was done to me. BTW what do those pulleys do? Would they help out anything on my motor?