underdrive pulleys?

[SilvRBullT8]

ok so i bet this has already been brought up but i was curious....are they really worth it and if so which ones are the best??????

[fadedSTi]

ok so i bet this has already been brought up but i was curious....are they really worth it and if so which ones are the best??????


i have the gfb ones and im pretty happy with them. not bad for the pricing and install. i had mine done at mastro

[SilvRBullT8]

what kinda power gains??????

[fadedSTi]

what kinda power gains??????

maybe a couple hp. it mainly helps you get through the gears alot quicker. you get to your peak power alot quicker.

[BrewPuBeaver]

personally i would go with a lightenD pully. there really isnt a need for under driven ones.

perrin makes some great ones that a few of my buddies have and they like them a lot.

[Alberto411]

maybe a couple hp. it mainly helps you get through the gears alot quicker. you get to your peak power alot quicker.

Exactly.
From what I've read online debating lightened vs. underdriven pulleys....
I hear that there are some re-charging issues with underdriven or smaller diameter pulleys. The economical alternative would be the lightened, but not underdriven, crankshaft pulley. The price ranges from $90-$150 and they can be a couple pounds lighter, but the same diameter which also lets you keep the stock belts, because the underdriven pulleys by nature will need a new set of belts.

-AL-

[BrewPuBeaver]

i forget the specific ratio of rotainal mass. but for evey lb you take off it is over 5whp.

and i know the Perrin is 5 lbs lighter.

[fadedSTi]

Exactly.
From what I've read online debating lightened vs. underdriven pulleys....
I hear that there are some re-charging issues with underdriven or smaller diameter pulleys. The economical alternative would be the lightened, but not underdriven, crankshaft pulley. The price ranges from $90-$150 and they can be a couple pounds lighter, but the same diameter which also lets you keep the stock belts, because the underdriven pulleys by nature will need a new set of belts.

-AL-

no issues with mine. been almost a year. they do come with new belts.

[lstepnio]

I had one of these installed on my '02 WRX and I honestly wouldn't say it was worth the money or effort. I never purchased one for my '04 STi based on my experience with the '02. I just wouldn't recommend it unless maybe maybe if the part was freebee.

[SilvRBullT8]

i was thinkin about goin with the 3 piece unorthodox set. anyone heard anything????

[Alberto411]

no issues with mine. been almost a year. they do come with new belts.

Good stuff. Yeah, most reputable sets like the GFB, etc. should come with new belts. I think most AEM sets also come with new belts. Just watch out for the eBay types ones that do not.

I've also heard that a lightened crankshaft pulley may throw a CEL at high RPMs because it throws off the crank-position-sensor.

Here is some info on the Unorthodox set. I wish I could say I was familiar with it myself or at the very least knew someone who had it on their car.

Unorthodox Racing Ultra Street Set pulleys. Come with a Crank Pulley, Alternator Pulley, and Power Steering pulley. Made of lightweight Premium 6061-T6 billet aluminum to ensure consistency of the material's strength and balance. CNC machined to .001". This is the complete Street pulley set that consist of the Ultra S crank pulley as well as all of the Ultra A accessory pulleys for each application. An average of 10 to 18 HP and 10 to 20 lbs.-ft. gains with these pulleys. Higher gains can be realized on modified engines. Power gains are obtained in two ways. First, and most important, is the weight loss. An average of 2.7 HP is gained from every pound lost off the crank shaft. With the lighter accessory pulleys, as much as 15% to 30% more power can be found. 85% of these gains are from weight loss. The rest of the gains are from underdriving, which accounts for about 15% of the total gains. Underdriving is not pushed for two main reasons. The main reason is to keep charging systems, air conditioning, power steering, and water pumps moving fast enough for every day driving. Second, not much horsepower is gained from extreme underdriving. Most of the underdriving is done with the crank pulley, not the accessory pulleys. This is done so maximize weight loss can be achieved at the crank where most of the horsepower gains are found. Available in natural polished aluminum as well as black, red, and blue anodizing.

http://www.rallysportdirect.com/shop/images/unorthodoxpulleysblack.jpg

*LINK* (http://www.rallysportdirect.com/shop/product_info.php/cPath/21_25_29_45/products_id/807)

[xFactor]

My experience with the UR 3 pulley kit was not too fun. The crank pulley was straight forward, and the alternator needed the touch of an impact gun, but the ps pulley was seriously aggravating. It required a puller, and I had to yank the radiator because it was cheaper than accidentally buying a new one. Then you broil the new spindlel in the oven for a half hour (no joke) and quickly and safely slide it on and let it cool.

Just do the crank pulley. I installed these in two stages, and the difference was not really worth the effort, and I'm all about worthless effort! There was a little voltage drop at idle with the under driven crank pulley, and not much of a voltage change with the aluminuim alternator pulley. It's noticeable rolling up into the driveway at night though the headlights.

The factory crank pulley is 11 pounds of cast iron porkiness, an aluminium one, 2 pounds. That right there helped the most.

Save the money and go for the crank pulley.
Have fun..

later, x

[SilvRBullT8]

cool thanx man

[M249SAW]

We have had no reports of all cylinder misfire codes from our GFB pulleys.

From what Ive seen on WRXs you only run into charging problems with an underdrive pulley when you go over the 1000watt range with car audio.

02 Wrxs had a stepped power steering pump shaft that made replacing those pulleys a PITA.

[HKSWRX]

I had one of these installed on my '02 WRX and I honestly wouldn't say it was worth the money or effort. I never purchased one for my '04 STi based on my experience with the '02. I just wouldn't recommend it unless maybe maybe if the part was freebee.

I agree, I wouldn't spend the money for the GFB's again if I had the chance, it made no difference, and it makes a wierd belt noise.