Underdrive pulleys?

**v2rocket** · 08-30-2006, 09:44 PM

anyone using these? are they really worth all the hype or am i better off spending my money on another upgrade part?

thanks in advance for a response

**Euro** · 08-30-2006 09:44 PM

**chrish01** · 08-30-2006, 10:13 PM

depends, wanna buy my unused, brand new eurosport underdrive pulley

though, its for a gti.

engines are designed very meticulously and balanced as such. you will be putting more stress on the engine than i feel its worth. especially if you are going BT.

however, i have one if anyone wants to buy it =P

**Ivan** · 08-31-2006, 03:14 AM

Underdrive pullys are one of the last things you want to do. .

Like a CD ignition or something unless vws have a crap ignition, but you get the idea.

**cynicalgeek** · 08-31-2006, 07:14 AM

Guess it depends on what you expect. The gains aren't enough for the butt dyno to really notice it much. I do like the improved response - the M3 definitely winds up quicker.

**iflyM3** · 10-27-2006, 04:43 PM

it all depends on what kind of car...on E36 M3's they are not that great. Their good if your building a track car and want to get every bit of torque you can from your engine. i wouldn't recommend getting a "lightened" underdrive (power) pulley for the crankshaft as it can mess up the harmonic engine balancer. for BMW's i would leave it to Rogue Engineering...
http://www.rogueengineering.com/Merc...tegory_Code=PP

as far as a quicker response, i would go with a lightened flywheel instead...and Active serves up a mean one...
http://activeautowerke.com/drivetrain/main.php

**mitssn** · 10-27-2006, 05:03 PM

Originally Posted by chrish01

depends, wanna buy my unused, brand new eurosport underdrive pulley

though, its for a gti.

engines are designed very meticulously and balanced as such. you will be putting more stress on the engine than i feel its worth. especially if you are going BT.

however, i have one if anyone wants to buy it =P

The point of an under drive pulley is to RELEIVE drag from the engine which would result in less "stress" on the engine...

**iflyM3** · 10-27-2006, 05:09 PM

Originally Posted by mitssn

The point of an under drive pulley is to RELEIVE drag from the engine which would result in less "stress" on the engine...

I would have to agree with that one...and if you mess with the crankshaft pulley (undrive it, or lighten it), it has the potential to throw your whole drivetrain off balance and could cost you either your tranny, or worse your engine...depending on the results of the damage. Especially BMW's. I'm not sure about other car's, but i am almost certain that they all have that (physics and such) in common.

when you relieve drag from the engine, that's where you find your extra ponies...usually around 5-10. Nothing more, it all depends upon the size of the engine.

..and again, as far as a quicker response...get a lightweight flywheel instead...with my Active Autowerkes Aluminum Lightweight Flywheel for my '95 M3 I feel like my car has lost 500lbs., and it moves into higher RPM's fast as hell...it maintains that high response rate even when i shift....and decelerates on da'fly. A lot more torque available sooner.

**Firefly4322** · 10-28-2006, 12:27 AM

I remember hearing about this from a shop, EIP, I think... They have been known to through your valve train off and mess up your engine. In a 1.8T or VR6....