Underdrive Crank Pulley
Thread Starter
Teching In
Joined: Mar 2010
Posts: 48
Likes: 0
From: Billings, MO
Underdrive Crank Pulley Has anyone done this on the Ls1's? If so, were there any setbacks?
I was just wondering if it potetially could burn up anything that was pulley driven(alt, psp, or water pump).. (by everything in theory spinning faster)
I was just wondering if it potetially could burn up anything that was pulley driven(alt, psp, or water pump).. (by everything in theory spinning faster)
Actually it makes everything spin slower, that is how you get power out of them. I have one in my car, and the only thing I hate about it is that my alternator output sucks when the car is not moving.
The underdrive pulley is a very cost effective way to produce more power without a need for tuning or any other modification. (normally). The accessories do spin at a slower rate then normal, so if you have an aftermarket system that has a high electrical demand, then it may be a good idea to have that addressed as well.
We sell so many of them, we even have them in kit form with the correct length belts and a new crank bolt, either GM or ARP style. They run in the $200 range for the kit depending on what crank bolt you decide on.
We sell so many of them, we even have them in kit form with the correct length belts and a new crank bolt, either GM or ARP style. They run in the $200 range for the kit depending on what crank bolt you decide on.
If the alternator output is a problem get the alt overdrive pulley. Some kits may even include that pulley in the kit. I just installed an UD crank pulley and put the alt overdrive on it and its way better alt output at idle.
TECH Fanatic
Joined: Feb 2004
Posts: 1,259
Likes: 0
From: Lexington, KY
I don't think the alternator output will be an issue unless you are running something that draws alot of power, such as big stereo amps. My car frequently sits for 3 weeks or longer without being started (especially in the winter). Sometimes it turns over slow but it always starts and the battery charges just fine, even while idling. I can start with a near dead battery and if I let it warm up and drive it just a few miles at low rpm it will start again in a few weeks no problem. So it's charging more than it's using for sure.
