Underdrive pully

compaqpunch · #1 12-27-2005, 10:05 PM

Does anyone know if this is as good as the $200 ones on 3sx?http://cgi.ebay.com/ebaymotors/UNDER...QQcmdZViewItem

94StealthTT · #2 12-27-2005, 10:29 PM

This is a good quality pulley. The OBX underdrive pulley works great but it does slow down the accessories. I had a problem with my alternator. It slowed it down so that sometimes the car died when I used a lot of electronics. It has improved since I got a new battery. I am also getting an overdrive pulley for the alternator to compensate for the underdrive.

Mikelb · #3 12-28-2005, 12:23 PM

I'd be careful... I hear that the underdrives (some of them, cheap ones) don't have harmonic balancers in them... they can really throw your crankshaft off, and destroy your engine... I decided I didn't wanna chance it...

compaqpunch · #4 12-28-2005, 12:31 PM

anyone else got an idea?

Mikelb · #5 12-28-2005, 01:16 PM

ok, from thinking a/b it... 3sx sells theirs for a decent price... considering... they're not much smaller than stock size (doesn't underdrive things) but they weigh a lot less... therefore, less rotating mass... I think that would be the best way to go... b/c running the smaller, u'd be in danger of losing precious oil pressure, water pressure... etc... I'd say, lightening up all that rotating mass is oe helluva way to make a car faster, lighter rims, lightweight flywheel, lightened pulleys... etc...

Think a/b it like this... rims, no body wants to go smaller...but they want faster...
the ud pulley is the same concept...
Don't go smaller (if anything, bigger)... the smaller rims would get u off the line faster, b/c the car has less to get you off the line, but to get you as fast as the stock size, they'd have to turn faster (ie. the loss of rotation to the altenator, pumps)... but larger wheels will get you off the line slower, unless you get lightweight wheels... then there's less force needed to turn the wheels, therefore quicker take-off and the wheels don't have to turn as fast to propel the car at the same speed as stock wheels...

Sry I rambled... but that's my $.02

Stealthee · #6 12-28-2005, 04:45 PM

Quote:

Originally Posted by Mikelb

I'd be careful... I hear that the underdrives (some of them, cheap ones) don't have harmonic balancers in them... they can really throw your crankshaft off, and destroy your engine... I decided I didn't wanna chance it...

There is ZERO proof that the lack of a balancer caused damage to engines. There is a greater chance of getting damage caused because the rubber falls apart and the pulley seperates.

94StealthTT · #7 12-28-2005, 05:40 PM

The underdrive pulley wont slow down the oil pump or the water pump because they are driven off the timing belt so dont worry about that. I had the same worries you had when I got my pulley. I looked into it first and I did not find any thing going wrong with them. No one really had problems with them so I decided to get one. There is not much of a harmonic balancer in it anyway and I have had no problems. The Ebay pulleys are so much cheaper too.

Mikelb · #8 12-29-2005, 07:14 AM

Quote:

Originally Posted by 94StealthTT

The underdrive pulley wont slow down the oil pump or the water pump because they are driven off the timing belt so dont worry about that. I had the same worries you had when I got my pulley. I looked into it first and I did not find any thing going wrong with them. No one really had problems with them so I decided to get one. There is not much of a harmonic balancer in it anyway and I have had no problems. The Ebay pulleys are so much cheaper too.

True, I really shoulda thought a/b that comment b4 I made it (water/oil pumps)... well, that's cool... I guess if I were gonna do it, I'd still try to stay near stock size, but that's really up to if ya wanna by that overdrive pulley for the altenator... sry u guys, I haven't had enough sleep lately to think clearly...

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