Underdrive pulley ?
Thread Starter
Cruising
Joined: Sep 2017
Posts: 10
Likes: 1
From: Oklahoma
Underdrive pulley ?
Hey guys, newbie to the corvette world. I've got a '99 with the crank underdrive pulley on it, & when I start it the alternator charges at like 9 volts for about ten minutes then kicks back up to normal. Is this normal, or is there something else needed to get it to stay at normal on startup. Not a big deal really, just hate having the charging fault thing pop up every time.
Le Mans Master
Joined: Sep 2014
Posts: 5,278
Likes: 539
From: Kelowna BC
I'm no expert, but an underdrive pulley is made to reduce power to accessories, in turn providing a small increase in power to the tires. Small.
IMO the payoff is nowhere near worth the entry fee, or the potential issues (had a friend years ago who had PS issues post an underdrive pulley install).
It's also entirely possible you have an alternator problem. Any problems starting the car, etc.?
IMO the payoff is nowhere near worth the entry fee, or the potential issues (had a friend years ago who had PS issues post an underdrive pulley install).
It's also entirely possible you have an alternator problem. Any problems starting the car, etc.?
Last edited by grantv; Sep 6, 2017 at 09:16 PM.
Thread Starter
Cruising
Joined: Sep 2017
Posts: 10
Likes: 1
From: Oklahoma
Well, it was done by the previous owner....but no, it has no issues starting or anything, becuase it does go back to normal charging after i would say 5-10 minutes. Now if i did drive it only a few minutes at a time it would be an issue obviously.
Drifting
Joined: Feb 2010
Posts: 1,923
Likes: 427
From: Dunedin Florida
I may be old school but underdrive pulleys are for silly little 4 cylinder japanese cars. Its a way to get HP to actually register on a dyno when you are sporting 1.8 litres. It offers so little improvement for the LS motor compared to the headaches involved. Get rid of it.
Thread Starter
Cruising
Joined: Sep 2017
Posts: 10
Likes: 1
From: Oklahoma
Unfortunately there is no removing it now so I guess I'll just deal with it. I did notice this morning that it's not for just a certain amount of time, it starts charging correctly once it hits about 3 or 4K rpms.
