Toothed crank pulley for supercharger

[Guest Anonymous]

Does anyone have a good pointer for a toothed crank pulley suitable for driving a supercharger?

Anyone have experience driving a supercharger with a V-belt?

Thanks!

John N

[Guest Anonymous]

Supercharger pulley.. um.. you're gonna be looking for mostly hotrod stuff like chevy/ford/chrysler stuff... alot of cogged belt roots type chargers... to spin that Supercharger of yours.. it's gonna load up that belt with about 30HP of lost power or more.. So back to Vbelts.. yes you can run vbelts but you'll need two tensioned vbelts to spin something like that without excessive belt slipage.. and we're talking about 8-10psi or less.. cogged you could go higher but you'd need custom belt and pulleys.. serpintine belts are usually good to 12psi or so on roots type chargers.. this is just from what I've seen from friends.. so give or take a SC with roots at 10psi = 210hp or so.. lot of power lost in spinnning that thing..

[Guest Anonymous]

From memory you were getting the eaton from a MB? I believe it will be a ribbed belt not a toothed belt on there. The charger I have from a Mazda is a ribbed belt.

A possible complication for switching to a toothed belt is the MB charger has an electronic clutch in lieu of a bypass valve. When you get the charger (maybe you have it?) it may very well be difficult to separate the function of the clutch from the pulley. Just a thought.

[Guest Anonymous]

I think I can work around the clutch issue. One of the advantages of a DIY EFI brain is that the code is open and can be changed. I'm going to have to do a little research into the control algorithm MB used, but I should be able to control the clutch. I was planning on a compressor bypass valve anyway (simple vacuum operated device) like they use on turbos to dump excess pressure.

So anybody know about where to get a ribbed belt??

Thanks!

John N

[Guest Anonymous]

Sorry I can't help you with the belt (maybe look at last years Grassroots 2002 challenge winner). Please keep the board updated on this! I am a little depressed about the weight of the mazda supercharger, but have not completely written off trying to use it. Positive displacement supercharger would make a rocking autox car IMHO.

The weight of the mechanism (rotating mass) is a detraction from the clutch solution if it is purely to decouple the charger at low loads. If it was also involved in boost management, that would be interesting, but I think highly doubtful.

If you have not already, I would take a look at the bypass valves used on the Jackson racing setups and Ford applications. No electronics involved, only manifold pressure/vacuum with a diaphram valve. To relate the mechanical valves actuation to the clutch engagement should be a good starting point.

[Guest Anonymous]

its the same model I have.

Thanks!

John N

[Guest Anonymous]

It is a different one. Based on the Lysholm design made by IHI. Was used on the Miller Cycle engines in the Millenium. (OT the Miller Cycle engine is a very interesting concept, amazing someone actually put it into production).