Ok guys what size pulley comes with a Radix 112 model for a 5.3? Is it a 3.25" How much boost is that supposed to be?

Reason I'm asking is my combo consisting of an LQ9, LS6 cam, stock heads with a 5 angle valve job, full length headers, and a single 3" exhaust with a 3.10" pulley will jump to 6lbs and come back to 5lbs on a run/pull. Does this sound about right?

I am considering dropping to a 3.0 or a 2.9 pulley. Where will that put me for boost? I am thinking it should be about 1lb per .10" smaller, so with a 3.0 ~6-7lb and a 2.9 in the ~7-8lb. Would this be too much boost for a 10.0:1 motor on 91 octane?

 

I'm running the 2.80 pulley and I only see 7-7.5lbs Im just running a stock LQ9 and stock cam. I also run 93 octane and meth.

 

the 5.3 comes with a 3.4" pulley. Head work and free flowing exhaust will make boost pressure drop but increase horsepower, remember boost is a measure of restriction measured in the intake manifold.
As far as the CR goes you will want to check the tune carefully, maybe consider Meth? My setup makes about 9 peak lbs with 9.9:1 CR.

 

What pulley are you running? How does your setup compare to mine. The tune is on the conservative side, but pretty much on. The AFR is 11.8-12.0 with 16* timing. With the 3.4 pulley we had timing at 20* AFR 11.8-12.0 with 0 KR. Ed wanted to leave a buffer for reliability and the chance of crap gas. How much will it change the tune if I went to say a 2.9 pulley and meth?

 

I'm no tuner so I can't really answer. My AFR is more like 11.4-11.7. Meth will allow you to keep a little more timing than without.