30% OD pulleys for MPIII/X blowers

XR7 Dave

Registered User
Gaging interest in a quick change pulley setup for M90 blowers that would allow you to run the MP 10% crank pulley and 10% JS pulley along with your choice of either a stock blower pulley or a 10% OD pulley. Other ratio's would be possible but those two would allow for the best choices. A 20% total ratio would provide 16-17psi on the street for safety with pump gas and then the 30% ratio would provide close to 20psi for track use. Other ratio's could be easily made after the hub/pulley setup is installed.

Drive ratio's higher than 30% have been tried with success for those who might want to try it. These pulleys would feature revised rib design, media blasted drive surfaces, and hard anodizing for maximum grip and long life.

Please post if you'd be interested in purchasing. If there is enough interest we will bring back a cost estimate. Looking for an initial run of 10 units for cost projections.
 
This setup could be used with the stock crank or JS pulley but it will be 10 rib in design. This is something that Mike Tuck (Super XR7) would be making if there is enough interest.
 
Dave,
The 5% Magnum Powers 10 rib pulley requires you to clearance some on the supercharger snout, how will the 10% 10 rib supercharger pulley clear?
 
Will these ten rib pulleys have the same spacing as the old ESM ten rib quick change kits? Will you also be offering the 10 rib jackshaft and potentially an 8 rib on that to the crank?
 
Will these ten rib pulleys have the same spacing as the old ESM ten rib quick change kits? Will you also be offering the 10 rib jackshaft and potentially an 8 rib on that to the crank?

The spacing is the same as the ESM kits. MP already offers the JS and crank pulley so we are not considering duplicating an already available product but they are all designed to be interchangeable with each other. However, this hub system will not interchange with the ESM hub system.

If this product comes to be we may consider an UD/OD crank pulley but that is another product which is independent of this one.
 
they make ten rib AR pulleys. I converted my kit to a ten rib. Just not sure if the offset will work with the standard setup
 
they make ten rib AR pulleys. I converted my kit to a ten rib. Just not sure if the offset will work with the standard setup
I'm not sure who you are referring to as "they". AR certainly doesn't make 10rib pulleys. You can make 20 rib AR pulleys if you want to, but the maximum rib count on the AR kits that I make (have made) is 8. This product has nothing to do with the AR. Everything is wrong, diameter, alignment, rib count, etc. Furthermore, the AR doesn't require a quick change pulley because the pulleys are not pressed on in the first place.

pablon2 said:
Question, will the existing 5% MP SC pulley work with the new MP hub?
These are not MP parts. As I said, Mike Tuck is thinking about making these because MP does not offer 30% OD pulleys. The proposed design would have a press on steel hub to which the replaceable pulleys attach with bolts which is what makes this a quick change setup suitable for track and street use with minimal effort. The MP pulley is a one-piece press on pulley which requires a puller to remove and should not be repeatedly removed and replaced as the aluminum will deform and the pulley eventually become loose. It simply isn't designed to be removed and installed multiple times.
 
The next question that should be on most people's minds IS.....will the 30% OD require a shorter belt compared to the one used with the 25% OD setup? Perhaps the answer is, "dunno, wait and see if belt slip occurs", but would be nice to be prepared beforehand if possible.

Regardless, this will be a great and very welcomed addition to the MPx arsenal. :)
 
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Belt selection is a challenge with M90's. In 10 rib the only belt available is the 12 rib 400. This belt is too long for the 10% setup. You'll have to get creative to run it. This means raising the blower slightly and/or slotting your accessory bracket bolt holes to lower the JS bracket.
 
Furthermore, the AR doesn't require a quick change pulley because the pulleys are not pressed on in the first place.

I realize that Dave but someone mentioned 10 rib for AR and I had bought a few ten rib pulleys for my AR kit. Im not saying they will work but there were a few companies that made them at least 2 years ago for the cobra and or lightning kits. I cant recall offhand who I got them from but I redesigned the AR I had for the ten rib setup. Its off topic but thought i'd mention it. If anyones interested in the info just PM me I'll see if I can find it
 
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