Crank pulley?

[Super2.2]

My buddy and I just did a supercharger build on his 2.2 Legacy. Its pretty sweet but he wants a little more boost. Is there a slighty oversized crank pulley anywhere out there?

[KevinWelker]

It is typical to change the size of the pulley on the compressor, not the crank pulley. Check for options on compressor pulleys from the supercharger manufacturer.

[Super2.2]

Yeah... we thought of that. But the charger he's got on it runs on a magnetic clutch so he can turn it on and off with just a switch. He doesnt want to get rid of that.

[pope_face]

I can't confirm anything regarding the pulleys, but watch that if you oversize the crank pulley, you're going to affect the PS pump and alternator, both of which would be a bad idea to destroy. If you end up getting an oversized crank pulley, you may have to swap out both the PS pump and alternator pulleys as well, or at least get the alternator rewired. Might be cheaper to just get a custom-made supercharger pulley.

[A1337STI]

Maybe you could install like a dual idler pully. (like what the crank is) have the crank turn the dual idler, use the 2nd pully on the dual idler to driver a belt that drivers your super charger. now you can play with the pully sizes on the dual ideler with out messing up anything else.

maybe just find some various crank pulleys and a way to attatch them in a workable spot... ?!? :)

[KevinWelker]

Even with an electromagnetic clutch it is normal to change the compressor pulley. What brand is the supercharger? What you are asking for is VERY common in the supercharger business and known sized pulleys are available to swap in, even with the clutch setup.

[Super2.2]

Its a SC14 Toyota supercharger off of a Previa minivan. While you can get a smaller pulley for this supercharger none of them allow you to keep the mag clutch setup. I've been looking around for months and asking on the toyota forums and everyone agrees that the best way to increase your rpms and keep the clutch on the SC14 is to just get a bigger crank pulley. Im just wondering if anyone knows of any aftermarket crank pulleys out there that are bigger and fit an ej22(or any companies that specialize in making pulleys and could give me a good deal).

[Super2.2]

There is one clutched pulley upgrade that i know of but it only increases boost about 15%... which is kinda pointless cause its only running 5lbs right now.

As for the PS and Alternator, we've already sorted out that problem by getting lifetime warranty parts from Autozone...:D

[pope_face]

Haha, well good to hear you've got the warranty problem sorted out... just don't let Autozone know you're running different pulleys... :P

I think the dual pulley setup makes sense... how is the supercharger currently run? Does it use the side from the AC compressor, or the one from the PS pump and alternator? If it's running in place of the AC compressor, then you could probably look into just making that part thicker. A possibility would be to get a pulley from a donor car, take it to a machine shop, get them to grind down the ribs on that section of the pulley (the rear), and then make a replacement ring that they can simply slide onto the pulley and weld into place. I'm not sure if it'll be cheaper than getting one custom-made, but at least you'd already have most of the material there, so as long as they can machine a "sleeve" to the proper diameter, and can balance it properly, it should be good. Plus, you know it'll fit properly on the crankshaft, and that the PS pump and alternator pulley is the right size.

I just thought of one thing that you'll have to look into though, and that's alternator clearance with a larger pulley... IIRC, the belt for my AC compressor just barely clears the alternator when it's all tensioned (I think there's under 1/2' of clearance). You may have to relocate your alternator to fit the larger pulley.

[Super2.2]

Its on the PS pump side. Thats a pretty good idea with the custom sleeve around the existing pulley though. I'll have to see if i can find a machine shop that wont rip me off too bad. lol.