View Full Version : Underdrive Pulley

celica girl
06-28-2002, 08:51 AM
Are these a waste of money?? I was gonna get the AEM pulley for my celica... any info would be greatly appreciated!

06-28-2002, 09:22 AM
I personally think they're a waste of time and money, they add very little horsepower and can lead to premature wear of the alternator and loss of power in terms of the electrical system. They may work wonders on some cars but from my personal experience and the experience of others I know..they are not worth the money.

06-28-2002, 09:22 AM
Pulley's don't make much of a difference, UNLESS you get the crank pulley, the crank pulley is the one that makes the most difference!

celica girl
06-28-2002, 09:26 AM
Thanks guys! AEM only makes the alternator pulley for my car... I think I'll wait and save for the unorthodox pulley set.

06-28-2002, 12:43 PM
IMO any sort of aftermarket pulleys aren't worth it. you might gain a few hp's if you put a lightweight and underdriven pulley on the crank. most stock crank pulley's are built with harmonic dampers which makes them absorb a lot of the crank vibrations. aftermarket pulley's don't use dampers for the fact that they are suppose to be light weight. in the long run you might cause more wear on your block bearings. just ask the 6 cylinder bmw and dsm guys. I'm sure they know all about this.

06-28-2002, 12:54 PM
underdrive pulleys are pretty much useless. They look nice I guess, but they won't give you any noticeable power unless we are talking about an old hotrod.

As 2000impreza said, the Unorthodox crank pulley does not have harmonic dampeners.

06-28-2002, 01:41 PM
Crank pulleys fall somewhere between your basic bolt ons and more invasive mods. Some cars respond very well to pulleys, others do not. On most modern cars, your crank pulley also acts as a harmonic dampener. On some cars they will run forever without this dampener, others will kill the bearings in less than 10k. Its a big crap shoot really. Reducing rotational inertia is always a good thing, but you have to weigh the potential for reduced engine life. Most hard core built motors use them, but at the same time most of those race motors are also only being asked to run 1000 kms before a full rebuild. That said, I've got a UR crank pulley on my car. Its not a mod you'll generally notice much from on its own, but combined with intake/exhaust/header type mods it can make a difference.

Audi Kid
06-28-2002, 04:38 PM
Originally posted by 4wheeldrift
Some cars respond very well to pulleys, others do not.

Exactly. On something like a mustang or ranger with a 2 valve/cyl pushrod engine, u/d pullies are a great investment.

Also, they work the engine harder, so a good mod to compliment them is something that works on cooling down the engine.

This is Ranger_X31

06-28-2002, 05:47 PM
Why bother with the little mods when you can go towards having positive manifold pressure :clap:

Pulley (just to stay on topic):
It's aready been mentioned that the crank pulley is the big one to look at. From my understanding your not gaining HP / torque just freeing engine load. Which leads to a better torque and HP curve.

The trade off is increased wear. I looked into one but I worry about bent valves and broken springs. Who ever thought of the deisgn of interference engines should be shot.:guns:

07-05-2002, 03:35 AM
Yeah don't waste your money Celica girl, just ask Redlyne_GT, he has it, and I don't think he has too many good things to say about them.

07-05-2002, 09:40 AM
Big waste of money. Get the crank pulley instead - you will feel a difference, but there are some problems associated with getting one as mentioned above.

5.9 R/T
07-05-2002, 12:54 PM
As with most every mod for a small displacement motor that doesn't involve FI you will be hard pressed to get much power out of it. However if you are planning on using it as a supporting mod for, lets say a turbo, then I would get it.