Is the 2.75" pulley the smallest for the Radix or is there a 2.7 available?

 

the smallest i could find is 2.75.

 

2.75" is the smallest I have seen. I personally would not want to spin my higher than what a 2.75" does.

I actually believe I gained more power on my Radix going back to a 2.9" I was shifting at 6200 (approx 17.5k Radix rpms), and believe it was creating too much heat to be worth it. Just something to think about. My gtec times were better with the 2.9" and I only lost about 3/4 of a pound of boost.

 

What I/C setup did you have?

 

I had the larger one that Magna now sends with their new kits. I had plans to use a powercooler at the track, but never made it that far.

 

maybe with some enhanced cooling, water/aclohol injection, further gains might have been realized with the smaller pulley? what's your take?

 

That is the same thing that a lot of the lightning guys have observed. If they go with an 8lb lower pulley over a 6lb on a stock blower (eaton m112) they gain some bottem end tq, but actually lose hp up top because it gets too hot.

 

are the m112 on the lightnings intercooled?

 

Well....any way you can lower the intake temps, you'll gain. I didn't have a good warm and fuzzy about spinning the crap out of the blower and really wanted it to last. I have heard that it can handle a little higher than what I was doing. The 2.9" pulley will drop the blower rpms down about 1k rpms. I believe even with enhanced cooling, the differences in a 2.75" and a 2.9" pulley will be negligible.

 

Yep, they have a pretty big intercooler sitting under their blower. I believe that it is actually decently bigger than the radix. Don't know how much better it performs though.

Running a better heat exchanger on the radix might allow you to run more boost, but there will be a point, where it can only cool so much. Plus you need to make sure you don't overspin the blower.