on another note if the radix is commonly operated up to 18k, I can still buy the 2.75 pulley and be OK.

8 x 6200/2.75 = 18036

if the lower pulley is actually 7.5" then
7.5 x 6200 = 16909

all things above holding true

 

How's the heat spinning em that high though? Do you have to compensate with less timing or better intercooling or gas etc? My point is it worth spinning it that high or is it just like trying to take a A-Trim Vortech and spin it up to make 15psi. LOL

 

F8L Z71, I can't answer that question completely, BUT, I can say blownchevy was running an LQ4 with a 2.8 pulley and upgraded heat x-changer with no problems.
I believe he was shifting at 5800rpms (remembering/guessing).

ergo 8 x 5800/2.8 = 16571

It might be safe to say, with the upgraded H/E and up to approx 16500 the radix is just fine.
I don't know what heat penalty there might be in the 16500 - 18000 rpm range though, but I bet the guys on the lightning boards know and brian

 

I don't think the bigger issue is heat in the motor at those high of RPM's. I think that after 16k you would start having to worry about things staying together in there. 18000 rpms is spinning really fast.

 

Does anyone know for sure the crank flywheel diameters for 4.8/5.3/6.0 motors?

 

whats up with this?

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Below are pictures and dyno charts from one of our test vehicles. Thee tests were done in 90 degree weather and reflect real world gains. Our test car consistently made nearly 480RWHP with our supercharger, pulley, cat-back exhaust, and intake kit. If you consider those numbers are at the rear wheels, this motor is really making around 560HP at the flywheel! Those products give a combined HP gain of 180HP!

 

Just measured my 5.3. 7.5 inches at the surface the belt rides on.

 

If that's the case ... mine's only getting about 15750 rpms ... who sells pulleys again ???

 

allen.
but there's got to be some hard specs somewhere, I'm gonna go check my service manuals.

 

no specs in the manual