smithflys23

What are the pro's and con's for underdrive pulleys? Particulary the cons, thanks

mAnYsTyLeS

Use the Search button at the top of the screen and you'll find TONS of info.

s197richie

Back when I had them on my 5.0 I seem to remember people saying they could cause overheating and/or undercharging problems at idle...but people say the darnedest things,you know. I know I read one thread on this forum where someone cross-threaded their crank hub when installing the underdrives and now are in need of at least a re-threading if not an entire crank, so be careful...but I guess 10 horse for 200 bucks is a pretty good deal for these cars...

Richie

p.s. but for less than 200 you can get some gears...of course the downside of those is that gearsetting is an art so you really need to have a good gearsetter or you'll get a lot of noise or worse...but I don't imagine the labor would be too badas long as you stay away from dealerships...

BillyBobJoe

I got my pulley's used for like 75 in the Parts For Sale forum. Good stuff there, should be a set on sale now if you look. Installed them myself with an impact and it took about 2hrs. Probably would have been quicker but I had just driven the car and so I had to work around a hot engine.

acascianelli

I'm also interested in the cons of UDP's.

I've heard that with a UDP that the air conditioning takes a little bit longer to cool the cabin. I don't think that the car will have any cooling problems because you replace the water pump pulley with a larger one to keep it running at the same speed.

BillyBobJoe

cons=minimal. The engine temp barely changes because of the new water pump pulley. The A/C might take an extra 1min at most to start cooling. Once the car starts moving and you get the RPMs up past 1K it should be fine. I've had the UDPs on for over a month and I still leave my A/C fan speed on 1 while driving. The voltage meter hasn't changed either. It's been slightly to the charging side the entire time I've had the car, before and after the install. The only con is if you install it wrong. Once installed properly, you'll be very happy.

Bluestar

There are no cons to report re: UDP's.

smithflys23

Thanks for the help!

djmac95

Not trying to hijack, but this could be a potential con... So I currently have a decent sized stereo system running two amps for about 1500 watts and I also plan to wire in a radar detector. I have stayed away from UDP's so far because I had heard that I could run down the battery due to the alternator not being able to fully do its job. Any thoughts on this?

Mikes_BLK_GT

yep that could cause some issues