Has anyone used underdrive pulleys on their car? Do they actually give you the power they claim? I have herd many mixed opinions on them.

 

on the third gen motors they do give a gain (more so than the lt1/ls1) because the water pump is still driven by the belt

i noticed a gain in top end pull with my March UD set on my old 305TPI

and i ha no problems with charging under normal operation, only noticed a drop in voltage when i hit my fan switch.

for $75-100 i'd say it was worth it

 

I got the "March"3 pulley set, believe it or not, I noticed a BIG "seat of the pants" difference!..I'd say it definitely worth it. If you have a big stereo/amp set up, you'll need the set that doesn't affect the alternator out put very much, I noticed my lights will dim a little a night at stops, but imediately comes back up when I get above an idle...

 

I dont think I will have a problem with the alt voltage, my alt charges high anyway, and the motor also runs too cold. LOL I havent used the fan one time since it got cold out, and with a 180 stat in there.....it runs at a constant 160. Thanks for the info tho....I think i may go get a set today!

 

Well, I too believed that the underdrive pullies would help. Because when one thinks about it, parasitic drag is what hurts gas mileage, and pulls horsepower off the motor. The alternator, power steering and water pump can pull up to 30 hp off the motor at high rpms, while this may seem crazy, its the truth. That is why when I bought my underdrive pullies, I got the racing set instead of the street set. I was not going to run a system, or anything that pulls any more power than what the car came with. I would recommend purchasing them from ASP racing, they make excellent stuff, and the prices are good. They have street and racing sets. So using my idea of being mostly a weekend warrior and soon to be mostly a drag car, I opted for the racing set. The racing set has a 51% crank underdrive, and 23% alternator underdrive. I noticed a definite seat of the pants increase in torque and upper end hp. I noticed no difference in cooling with the factory water pump, but I installed a edelbrock pump I picked up for 80$ with 3K miles on it. My car ran between 140-160 degrees under most driving, and never got hotter than 210* when in 90* plus weather and sitting in traffic for 45 minutes, with one fan running all the time. I did also notice that the motor revved alot faster, and my mileage around my house, which is mostly rural between 40-55mph, My mileage was 20-22 mpg, as opposed to 16-19 before the pullies. However I didn't notice a gain at the track, but I was slipping in the first 60ft, so that probably didn't help anything, damn p255/50r16 pep boys tires from the previous owner.

 

are you serious!? is that all that you changed, the pullies?

Man, I gotta get a set of those!

I dont' run any stereo or anything, but my fan does run all the time, would that be a problem?

I finaly got my car to get 14 MPG (up from 9 or 10MPG), think the pullies would help?

 

I used a farad cap on my 89 Rs(305 TBI), and that pretty much eliminated any lighting probs. I've heard the underdrive pulley's are really good investments too, anyone have a website link for them???

 

Yes I did get all that stuff from the set of pullies. You will be fine with one fan running. My normal fan runs all the time, and if I want I can turn on my other a/c fan, but I rarely need to. The only thing I would recommend if you get the racing set, is to use them more sensibly, I mean, don't leave your car idling for ever, or leave the headlights on for hours, and that type of thing. I have a 300 watt rms pioneer amp, kenwood head, infinity kappas, and I used the stereo when I wanted to, and I never had a problem with charging. However when I was at the track and I left my a/c fan on while the car was sitting, I noticed it pulled the battery voltage down a little, but that was when the fan was running for about three hours all together between 5 runs. After this I made sure I charged my battery up some, but its not a big deal. With the racing underdrive set, the car has full charge at 1450 rpm, and for me thats just under normal cruising. I would also recommend that you buy a voltmeter if you get the racing set, it helps to monitor the battery. I believe the website for ASP is www.aspracing.com , check them out, I was thouroughly impressed with the cnc quality of there parts. The racing set is also made per order, so you may have to wait longer to recieve them.

 

get the march pulley set... it's worth it IMO

 

i have the jet power pullies and i did notice a torque difference. and my cooling never changed at all. i dont recommend changing your water pump pully. just the crank and alt should be fine. if your running an 85-87 take off your a/c and smog pump belt for more power all in all for a 100bucks pullies are a deal