jmac72187

I have heard a lot about underdrive pulleys getting some more power out of cars. But I have a few questiosn about them.

Will they make any power difference if the accessories like heat are off anyway? I don't usually use AC or heat.

How hard are they to install for a newbie like me?

04BlueGT

1) Yes. Besides, heat does not tax the engine like AC anyway. The compressor only runs with AC and defrost. Heat is just a byproduct of the motors friction and combustion. Using the heat does not sap horsepower.

2) Easy to install. Here is a link to the write up I did a while back. https://mustangforums.com/fb.asp?m=2144008

bumpinwheels95

ne one maybe about how much power should come with those? i heard btween 2-6 rwhp but i dunnno seems high but is that right>

97targa

Actually using heat helps take away heat from the motor!! The first thing you should do if your engine is overheating is turn your heat on high to help cool down the motor(an old trick). But underdrive pullies don't do anythin really unless you have a tune for them. I personally don't use them because I like my A/C when I use it and want it to be Cold not Cool. Another thing is the alternator, I need energy to feed my stereo equiptment, so if you have a stereo you'll need your alternator. It will drop from 130 to 105 or if yours is a 99-04 mustang it will go from 110amps to 85. The waterpump pullley blocks the way of the alternator bolt, so if you burn up your alternator you'll have to take off your waterpump pulley to do so! Also if your looking to do timing gears, which why people don't use a programmer is besides me, but if you do plan to use them, your going to have to get Steeda U/D pulleys, because you can't use piggybacking U/D pulleys with them!

bumpinwheels95

so ur saying if u get pullies u wont have a/c and ur altenator will decrease power? that doesnt make sense can u explain further

xxkazp3rxx

Ok, I had Pullies in my 2v before I sold it. It DOES NOT, and I repeat DOES NOT affect the way your car runs, as far as your a/c, heat or anything. Whoever said "they will not add anything unless it's tuned" is completely wrong. The way the pullies work is that they don't "add" horsepower... they free it up. . With pulleys you're just not having as much drivetrain loss for horsepower. The average gains range between 3-8rwhp, (Yes, i've seen dyno's in the shop after the pulleys)... that depends on how much you've done to your car as far as power goes. A 500rwhp car thats making (550-575hp at the motor) will have more gain from pullies then a car that has 225rwhp and 260 at the engine.

As far as install goes, it's not to difficult, just make sure you have a puller for the crank pulley and an impact wrench to get the bolts loose. If you have access to a lift, i'd use that access. It was just easier once the car was lifted on mine... besides i dont like getting underneath cars with stands/jacks... lol kinda freaks me out :P

EDIT: Alternator power, it's concievable that it might cause a loss in power, but i never experianced any in my car. Then again, I can see someone that has ricer lights, and (2) 15" subs in the back with 4 amps having issues with it. If you've really not changed anything electrical i don't forsee any problems you'd have.

bumpinwheels95

thats what i thought im sure if u have a tune to go with the instillation of the pullies it will help benfit the hp more but he said it will only ad hp if u got a tune ( i have a tuner so im not worried)

good post kazp

wes ley n the G T

Yea man, you dont need a tune for any type of pullies besides new supercharger pullies. For underdrive pulleys, no tune is needed. As Kazp said, they "free up" horsepower from less parasitic loss.