adrianmt75

Newbie Question...

I'll probably end up buying a Radix unit by years end. I am an Eaton employee so it is a must have. I was on the Lingenfelter website last week and saw that they have the CNC Ported Cylinder heads and camshaft package on sale while supplies last. I was thinking of picking-up the heads prior to the Radix simply to gauge the impact of each and for installation ease. Also, won't the freer flowing heads allow me to run more boost? Maybe a 3 inch pulley or so. I'm avoiding the bottom end for now (mainly because of cost and downtime) , although I certainly see the value in a balanced lightweight crank and forged pistons.

Is this a doable set-up for a daily driver? What should I keep my eyes peeled for?

Also, I chucked my original airbox and tube and it doesn't appear that I can use my current K&N FIPK filter element and shield. Is the Air Raid set-up the only candidate. I called Volant and they are coming out with a Ram-Air set-up for the Denali front end Trucks.

My truck is a 2001 GMC Sierra C3 w/56k miles. Current mods are mild bolt-ons: JBA Headers, Granatelli MAS, K&N FIPK, Flowmaster Force II, Wester's Program.

Thanks in advance for your help.

Mr. Sandog

Depending on how the heads get done, the same pulley may end up yielding less boost. For example, if the stock 3.4" pulley gives you 5.5 psi boost, after the new heads get installed, you have to go up to a 3.1" pulley to get the same 5.5 to 6 psi you had prior, because of more free-flowing heads. Of course, you will have much more power because of the heads, cam, and boost combo, but your boost could be lower.

Keep in mind that the theoretical limit of a Radix is around 18,000 RPM's.

O3GMC

I'm pretty sure people use their FIPK with the Radix, just takes some adjusting

adrianmt75

I agree Naked AV.

We had a guy on the MSN C3 thread that was running a Whipple and did some head work and what you describe above occurred.

Is there a correlation between detonation and freer flowing heads?

When you say 18k RPM limit are you referring to the specified or theoretical limit. If it is an 18k RPM specified limit I've got a 10-25% buffer. If it is in regards to theory or design limitation, what is keeping it from exceeding 18K?
If 18k is the limit and the unit cannot exceed 18K then will the boost simply level out instead of continuing to climb with the engine RPMs. Or will the RPM disparity cause me to skip a belt or something worse.

Will a 3" pulley put me over 18k RPMs on the blower? I was thinking of only running the 3 incher at the strip and keep the stock 3.6 (I believe) or 3.25 in for the street.

I believe there is someone on this thread that is running a 3 incher without head work so I think I am safe except for a tune.

Mr. Sandog

I think 18,000 RPM limit is a design limitation related to the Eaton M112. But don't quote me on that, I'm just repeating what's been said around here by other Radix owners. It would be best to call Magnuson or talk to someone at Eaton about it (or both might be even better). If you do, please come back here and give us what came from the horse's mouth.

As far as what pulley diameter will put you over, that is a function of crank pulley diameter, Radix pulley diameter, and engine RPM. I think it's Crank Pulley Diameter / Blower Pulley Diameter X Engine RPM = Radix RPM.

Regarding detonation, from what I know that is caused by running lean. I'm pretty ignorant in this area so we will have to wait for someone more knowledgeable to chime it about that topic.

Yelo

actually....I believe the max rating for the MP112 is 14,000rpm.....most have been spinning them to 15-16,000rpm or so but 18,000rpm is WAY outside the max rating

gearheads78

iTrader: (29)

I have the 3" pully with a Nelson tune and no other mods other than exhaust. Runs real well.

Mr. Sandog

adrianmt75 - what kind of vehicle & motor do you have?

Richard - do you have any idea what the diameter of our crank pulley is?

adrianmt75

2001 GMC Sierra C3 6.0L AWD w/o Quadrasteer.

Any thoughts on my question about detonation Guys???

gearheads78

iTrader: (29)

Not sure about the stock pully. My stock truck with tune shifts about 5800 at WOT so there sould not be a issue with turning the blower too high.

I asked Allen about detonation and he said with the 3" I won't have any problems. I don't have a scan tool but there has been no audible pre-ignition.
I do have the larger Radix HE so that may help also.