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-   -   Supercharger Crank Pulley (https://www.miataturbo.net/supercharger-discussion-38/supercharger-crank-pulley-89832/)

Madjak 07-20-2016 01:21 AM

Supercharger Crank Pulley
 
Does anyone know of a 6 or 8 rib pulley that will fit on a decent miata damper? Options I've found so far are:

1) The 949racing Supermiata Supercharger 6 rib pulley. It is 152.4mm diameter which means if I get a C30-94 I'd need a 115-120mm pulley on the Rotrex to keep it under it's rated max speed (max RPM 8500). The largest pulley for a Rotrex that I can find is 110mm.
2) The other option I can find is bolting another pulley to the ATI damper, but the smallest I can find there is also over 6" and designed for v8s so same issue as above
3) I could keep the stock harmonic balancer and bolt a TDR or FFS 6-rib pulley to that, but I'm going to be pushing for serious HP and I'd prefer to run a better damper.
4) I've found a 6 rib Fluidampr VW pulley that could be modified to bolt to the stock timing belt gear and replace the OEM damper but then I'm running something entirely unknown.

Maybe I'll have to make up a custom pulley to fit an ATI. I'm not worried about placement as I'll be custom mounting the Rotrex plus I'm not running a waterpump and so could drive both the Rotrex and the alternator from a single belt, however I'd be concerned about the tension causing issues with the alternator.

The other option is to shoot for a C38 and then I have no issues with drive speed with the larger Supermiata pulley. I can actually get a C38-91 very very cheaply, however it's a monster and far too oversized for a Miata engine.

Madjak 07-20-2016 04:18 AM


ATI has designed a 5.5” damper -- Part # 918522 -- for the '94 - '05 Mazda Miata 1.8L engine for high horsepower street & race use. This new design is a direct replacement for the stock OEM damper. The heart of this unit is the tried and true “damper within a damper” design that has put ATI ahead of the rest. The outer shell is machined to utilize the factory serpentine belt set-up. Bolt On 5.5" Billet Aluminum Supercharger Pulley available, Part # 916267.
I should read the ATI catalog really as there is a bolt on supercharger pulley available Part no 916267. There is no reference I can find on it online but it sounds like it's the correct sizing (139mm diameter) and will drive the C30-94 at the correct RPM with the maximum 110mm pulley. I've emailed ATI for more info.

3rdCarMX5 07-20-2016 12:27 PM

I have an ATI and a pulley to match, I am not sure of the source, but I think it is FM. I would call them as they have access to the ATI catalog and some custom parts from their super charging experience. It isn't cheap but it bolted right up and worked well. I do not know the diameter off the top of my head but it matches the OD of the damper.

patsmx5 07-21-2016 10:24 PM


Originally Posted by Madjak (Post 1347642)
Does anyone know of a 6 or 8 rib pulley that will fit on a decent miata damper? Options I've found so far are:

1) The 949racing Supermiata Supercharger 6 rib pulley. It is 152.4mm diameter which means if I get a C30-94 I'd need a 115-120mm pulley on the Rotrex to keep it under it's rated max speed (max RPM 8500). The largest pulley for a Rotrex that I can find is 110mm.
2) The other option I can find is bolting another pulley to the ATI damper, but the smallest I can find there is also over 6" and designed for v8s so same issue as above
3) I could keep the stock harmonic balancer and bolt a TDR or FFS 6-rib pulley to that, but I'm going to be pushing for serious HP and I'd prefer to run a better damper.
4) I've found a 6 rib Fluidampr VW pulley that could be modified to bolt to the stock timing belt gear and replace the OEM damper but then I'm running something entirely unknown.

Maybe I'll have to make up a custom pulley to fit an ATI. I'm not worried about placement as I'll be custom mounting the Rotrex plus I'm not running a waterpump and so could drive both the Rotrex and the alternator from a single belt, however I'd be concerned about the tension causing issues with the alternator.

The other option is to shoot for a C38 and then I have no issues with drive speed with the larger Supermiata pulley. I can actually get a C38-91 very very cheaply, however it's a monster and far too oversized for a Miata engine.

I have a 5.5" 6 rib pulley that is currently attached to my ATI Damper. For sale if you want it.


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