How should I OD my MPII?

How should I overdrive my MPII blower???

  • 10% OD supercharger pulley + stock jackshaft

    Votes: 4 26.7%
  • 7-10% OD supercharger pulley + stock jackshaft

    Votes: 1 6.7%
  • 94/95 SC pulley + 10% jackshaft

    Votes: 7 46.7%
  • 94/95 SC pulley + 5% jackshaft

    Votes: 3 20.0%

  • Total voters
    15

tydlwavs

Registered User
I have a couple options here and I want opinions on the best way to OD the SC. It already has the 10% sc pulley, but I know it's a better option to run the jackshaft OD pulley to keep belt slip at a minimum. Engine is stock with 86k miles. It's a junkyard 95 motor with new bearings and seals.

I have the MP springs, catless exhaust, K&N intake mod, underdrives, stock 36's for now with stock 94/95 plenum, MP FMIC. Any info is appreciated. Car will obviously need injectors and the inlet plenum. That's next on the list.
 
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Pitch the underdrives and run the OD Crank and Jackshaft with a stock supercharger pulley. I didnt see much help at all from the underdrives and with trying to keep belt slip at a minimum you want to have as much contact as possible on the SC pulley. Just my two cents.
 
Personally, 5% SC and 5% jackshaft.

Fraser

That's what I did. On the dyno, I was starting to have a bit of belt slip towards the end, but I think if I had the MP springs - I wouldn't have had the slip.

-Melon
 
Run 15%, 5 on the SC and 10 on the JS, and keep the UD's. I ran the MP 10 rib 15% kit on mine and made 265rwhp on a stock block.
 
Overdriving with the crank pully and jackshaft is best, because it increases the surface area for the supercharger belts to grip.

David
 
I was told that the 10% SCI jackshaft overdrives the crank 5% and the blower 5%. Is that true? Just want to verify this.
 
I was told that the 10% SCI jackshaft overdrives the crank 5% and the blower 5%. Is that true? Just want to verify this.

Todd,

The overdrive on my ESM 10% jackshaft pulley is all on the supercharger belt side (it's 10% larger OD). The portion that is driven from the crankshaft pulley is the same diameter as stock and still uses a stock belt.

Don't know anything about how SCI does it.

David
 
I can't get to the search function for some reason. I'll have to ask Ryan. I do have MP springs and I'm lookin pretty hard at the 94/95 pulley and a 10% jackshaft pulley so I am not quite running a full 10% OD. I'll see if my 5% belt fits this set-up.

Just waiting on payment for my 5% and the 10% sc pulley to make my purchase later today.
 
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