What is the smallest pulley available for the Radix, and what is the corresponding boost? I'm starting to put together a plan for my new setup.

 

boost depends on many many things. smallest pulley available 2.75".

 

Then I'll describe what I'm aiming for. I want to put in an LQ4 block with a mild cam designed for FI, and heads that will maximize compression based on how much boost the Radix will put out. I figured that getting a number for psi would allow me to start looking at what kind of heads to buy. Shooting for ~650hp flywheel.

 

LQ4 with stock 72cc Heads and stock 9.4-1 compression ratio and the radix with a 2.8" pulley = about 10 lbs of boost ala BlownChevy.

 

Is that about the most you can stuff in there without detonation or is there room for a little bit more?

 

At one point I was making 12lbs with a 3.25 pulley

 

did you weld something over the intake ports or what??

 

I suppose it would depend on a few things but I'd be willing to bet you could get a little more.

 

That was on a 4.8L

 

Excessive boost isn't needed. Build the motor to be effecient and it will run good. Of course, more boost is usually better, but not always.

On a 6.0 I would shoot for ~9:1 CR and go from there.