Every product made has limits, upper and lower. At what point, in engine RPMs, does the Radix become less efficient from overspin?

And at what RPM for the smaller pulleys?

The reason asked: Suppose you change the cam. The new cam powerband has a higher RPM range. In theory, based on RPMs, you could overspin the blower before you get to the peak HPs of the cam.

It would only matter if the overspin would occur when the engines RPMs were under 7000 RPMs. Not saying I plan on spinning it to 7000 RPMs, but the blower would need to be able to handle that rate at minimum.

 

The blower is rated at 14k rpm.

Use this formula to get the blower rpm:

7.5 (crank pulley size) * RPM / <blower pulley size>

 

I figured it would be well above any RPM I would reach. But wanted to make sure before dropping that amount of cash.

I notice that there are not a lot of head/cam mods with the Radix. Do you think this is strictly because cash flow or is it simply not needed? It is my understanding that the 5.3 heads flow very well and the only change really benefical, from a torque perspective, is increasing the valve sizes.

 

Wow...if you're planning on spinning up to 6500rpm, you can only use a 3.5" pulley? Wonder how much boost it would build at that RPM?

 

The blower would still be good up to 16-17k, but by magnuson's reccomendations you are correct. You could get away with about a 2.9" pulley max if you are spinning to 6500. That would put you at approx 16,800 rpm. Some lightning guys go even over 18000 rpm, and don't grenade their stuff.

 

18,000 reliable rpm for the Radix.

how do I know that?

a birdie told me

 

If you plan on many upgrade I would to something other then the radix. It is godd even grat to a certian point but will not do well with big cubes or great heads and high RPM's. In other words it cannot supply enough air if going a little overboard is your intention.

 

I've been considering a head/cam setup with the Radix, but haven't started really researching yet. I'm curious if the Radix could pull enough air through good flowing heads/moderately aggressive cam. My goal is about 500rwhp, just wondering if I'll have to look into a nitrous setup to get there. (dual power adders, nitrous + blower.....KABLAMO - from personal experience )

 

Nine Ball put a Radix on a 5.7 with a cam. Can't remember if he did heads. He was just over 500 rwhp & rwtq. I believe he was at 400 rwtq by 2k rpm.

 

Yeah, but that was w/ forged internals and through an M6.

https://ls1tech.com/forums/showthrea...&highlight=500

500 rwhp on a Radix'd 5.3 would be a feat!