Z28LS1camaroguy

iTrader: (3)

well i searched and didnt find much but im wondering what is the difference between the 25% and 10% underdrive pulley??? and also who sells that pulley tool since im gonna be purchasing the SLP powerbond underdrive pulley and a overdrive alternator pulley to go along with it, and i will be installing myself what are the steps to do it right????

Z28LS1camaroguy

iTrader: (3)

??????

Z28LS1camaroguy

iTrader: (3)

I found this but dont really want to spend money on something i will be using once or twice, any other alternatives to getting the pulley to fit over the snout better???? other than heating in the oven aswell???

bww3588

iTrader: (49)

15 percent............

1slowls1

iTrader: (1)

I would say ones smaller than the other one, i believe summit racing sells the tool but i really shouldnt say that since there not a sponsor here.

Kage

iTrader: (11)

Don't do it, waste of $$$$$.

bww3588

iTrader: (49)

yes the 25 percent underdrive is smaller than the 15 percent. if you have an M6 you may not need the alt overdrive pully, but if you have an A4 you will definately need it.

orangeapeel

iTrader: (18)

I would do the 15 if you plan on DD'ing this car.

bww3588

iTrader: (49)

my bad, i ment 10 percent not 15......sorry. yes Jordan is right, 10 percent would be good for a DD

Z28LS1camaroguy

iTrader: (3)

so i should go with the 10% rather than the 25% underdrive???? im getting the powerbond one and thats the only percents they sell, so what does the 25% and 10% mean exactly????

jmm98LS1

iTrader: (28)

The higher the underdrive percent, the smaller (in diameter) the crankshaft pulley. The smaller the crank pulley, the slower your accessories (alt, a/c, ps, wp) will spin.

Z28LS1camaroguy

iTrader: (3)

so i want 10% percent to free up some power and i will get a overdrive alternator pulley to boost up the volts since i have a system in my car.

bww3588

iTrader: (49)

yes, you can do that or you can get a higher amp alterator to avoid the OD pulley.

Z28LS1camaroguy

iTrader: (3)

where would be the best place to buy a higher amp alternator and what all is needed to install it??? so why do they make the underdrive pulleys if they dont do crap???

bww3588

iTrader: (49)

the UD pulleys do work, but what im saying is get a higher amp alt so you dont have to put an OD pulley on your alt. if you werent running a system in your car, your stock alternator and pulley on the alternator would be fine with a 10 percent UD crank pully. but since your running a system, it probably wont be. so if you get a higher amp alternator, you wont have to put an OD pulley on your alternator to get it to spin faster. to me, putting an OD pulley on the alt is kinda defeting the purpose of an UD pulley on the crank.

Z28LS1camaroguy

iTrader: (3)

but it will be fine either way right??? how much does a higher alternator cost?? and how big of a alternator should i go???

FieroZ34

iTrader: (1)

Don't do an underdrive pulley, bottom line. The poor affects of the pulley are not worth the 5, maybe 10hp you'll gain. Put the money towards something that won't kill your charging system and battery, overheat your car, weaken your A/C system, and God knows what else. GM made the pullies the size they are for a reason.

KurtRardin

iTrader: (11)

I agree. Nickels and dimes worth of HP arent worth the hundreds you'll pay for it. You could pick up a used cam that would throw 40RWHP your way for that kind of money. If it were a $50 mod then yeah, its worth it.

I certainly didnt feel the 11hp the TB airfoil was suppost to add for my ol' LT1, nor did i with the pulleys. Now as I recall you could feel the headers and 4.10 gears, lol. For $200 theres a better performance part that you'll feel.

Kage

iTrader: (11)

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