I need a set of pulleys for my motor builld.

I noticed Unorthodox only sells an underdrive crank pulley. They do not offer a stock diameter pulley.

Do I want to underdrive? How does it affect the AC, the PS and the altenator? I'm in FL I need the AC kickin.

I imagine all the pullies would be:

1 crank?
1 idler?
1 altenator?

There are no PS pulleys and no AC pullies available?

Respect
JET

 

in CA, my AC was fine for the 60,000 miles I had my underdrive crank pulley on...

The Power Steering / Alternator pulley's are the same size and weight as the stock pulley's... only change them for looks... they are such a hastle to change its not even worth it... we charge an extra $220 labor just for those two pulley's...

With the Power Steering, you sometimes feel it get a little harder when the motor is at 800 RPM if it bogs down, but thats about it, besides that, it feels better IMHO... You kinda feel it more...

The KJR Stock size light weight pulley is another option if you are worried about anything...

besides that... never had a problem with the UR pulley, worth every penny... one of the best mods (crank pulley only) per dollar for the Z!

http://mynismo.com/products/?id=4366&rsku=19083

 

JET I wouldnt even consider it with a built motor. Is it worth the possible risk on a motor thats gonna be built and expensive? Whats 5whp when your way over 400whp? Im ditching my UR crank pulley for the build....

 

I got the UR pulley set...love it and everything works fine; but I agree that the only one you really need is the crank. (The Alt pulley was a huge pain to off!)

 

So for a built motor, it's really not that useful. NA motor's a different story right? I mean it's worth it? Most of the people that have them seem happy with their purchase.

 

I've been running the UR pulley set for about 10K miles. The only problem I have is that sometimes when I start my car the a/c compressor seems like it doesn't start blowing cold air until I get in the upper rpms. Once it starts blowing cold it's fine. Sometimes I will just turn the a/c off and turn it back on really quick and it will be fine. Other than that no problems. Lots of people are running UR pulleys with built motors. I can't recall anyone ever posting problems.

 

See how your engine builder is going to do your motor... is he going to ballance the crank with or without the flywheel / pulley on...

IMHO, the UR crank pulley is better ballanced then the OE Cast Iron pulley...

We got 8 RWHP out of the UR Pully on an NA car... on a turbo car... My guess would be a multiple of that...

 

The crank pulley actually helps exponentially depending on the engine set-up. Turbo set-ups REALLY shine with the reduced weight.
When we used to put pulleys on the 300zx, the n/a would post a moderate 5-7 HP, while the best gain we got on a BUILT turbo engine was 40 HP!!!!

As for me, my engine is N/A with the UR pulley. There is no way I would take it off. Usually the people that post "horror stories" aren't very mechanically inclined Like their opinion that the mechanic that changed their oil is responsible fot their radio not working now - I get this everyday.

 

ok, please dont flame me... but how about the harmonic balancer, whatever it is, thats built in the pulley itself? doesnt that come into play?

 

there is no risk to installing this or any pulley on a built motor or a stock motor. Same as doing a flywheel on a built or stock motor. If the part you are installing is itself balanced (which the UR is...perfectly), there are no risks whatsoever.

This especially true when building a motor with a pulley in mind - give your machinst your clutch/flywheel and pulley (ies), and you can have an entire bottom end balanced and blueprinted as a spinning unit (assuming you are paying to have your motor built this way, which is recommended)

There is no harmonic balancer built into the stock pulley - it's simply there to absorb the noise of the accessory belts

 

If Im just replacing the crank pulley with the UR crank underdrive pulley, what belts do I have to replace and if anyone has part numbers Id appreciate it.

 

http://mynismo.com/products/?id=4325