To get or not to get a aftermarket Pulley kit?!?!?!?

[TracOwner]

It's time to replace my current pulleys and I was wondering if it's a good idea to get one of those aftermarket pulley kits (non OEM). I know that a lightweight crank pulley should give me +5hp or so but I've heard that putting it on increases the chances of crankwalk.

So once again, the question is: To get or not to get an aftermarket pulley kit?

If it's ok to get it, which ones should I get? Unorthodox, AEM, OBX.........?

 

[Fb90gsT]

Stay with OEM. Dont mess with aftermarket pulleys.

 

[TracOwner]

Why not?

 

[DSMjrv]

i have a light weight crank pully and they suck... u dont feel any extra power... and the car becomes easier to stall... no momentum on the motor...

and all the other pullys with smaller diameter whatever... are kinda bad for ## car...

 

[IHeartTurbo]

http://www.bmwplanet.com/phpbb/viewtopic.php?t=25284&sid=fa32aa2045bb4227d82a74a6a3a6a458

and the car becomes easier to stall... no momentum on the motor...

Wrong. The crank pulley doesn't do anything like that. The flywheel could, but definitely not the crank pulley. The reason for going with aftermarket pulleys is mainly not because of the weight, but because it will spin all the accesories slower, reducing their load on the engine.

 

[halligoo]

I wouldn't recommend dinking with the pulleys if you use your car as a daily driver. Some mods were just meant for racing and this fits that category. It isn't worth the risk of the potential crank damage. Stick with the OEM stuff and you won't be kicking yourself in the butt up the road.

 

[EvolvingGST]

I wouldn't recommend dinking with the pulleys if you use your car as a daily driver. Some mods were just meant for racing and this fits that category. It isn't worth the risk of the potential crank damage. Stick with the OEM stuff and you won't be kicking yourself in the butt up the road.

I agree plus there are better mods for the price and just not worth the caution.

 

[TracOwner]

I wouldn't recommend dinking with the pulleys if you use your car as a daily driver. Some mods were just meant for racing and this fits that category. It isn't worth the risk of the potential crank damage. Stick with the OEM stuff and you won't be kicking yourself in the butt up the road.

But shouldn't this reduce the risk of crank damage.......I mean it reduces the load on the engine so.....

 

[oldman]

But shouldn't this reduce the risk of crank damage.......I mean it reduces the load on the engine so.....

Nope. http://www.dsmtuners.com/forums/showthread.php?t=198897

 

[Denji]

Torsional Vibration (Natural Frequency)

Every time a cylinder fires, the force twists the crankshaft. When the cylinder stops firing the force ceases to act and the crankshaft starts to return to the untwisted position. However, the crankshaft will overshoot and begin to twist in the opposite direction, and then back again. Though this back-and-forth twisting motion decays over a number of repetitions due to internal friction, the frequency of vibration remains unique to the particular crankshaft.

This motion is complicated in the case of a crankshaft because the amplitude of the vibration varies along the shaft. The crankshaft will experience torsional vibrations of the greatest amplitude at the point furthest from the flywheel or load (i.e. pulley location)This information was supplied by Steve Dinan (BMW GURU). Although it's not a DSM it's still universal.

above taken from boostcreep's post on this subject -link---->http://www.dsmtuners.com/forums/showthread.php?t=173340&highlight=lightweight+pulley


*the lack of the dampener on the aluminum crank pulley is what makes this dangerous, as you may know the stock one is dampened, to help deal with some of this vibration described above. Also, some say that the aluminum aftermarket ones are not balanced to oem specs.

 

[Mist3r Spool]

IMO, pulleys are just cosmetic. Some under-drive accessory pulleys will give your a pony or two but that's all. I don't think the price justifies the result. I would definitely stay away from aluminum crank pulleys, they have been proven to lead to uneven bearing wear and crankwalk. If you must have an upgraded pulleys and crank pulley, make sure that the crank pulley has a dampener. The only company out there that fabricates such a product (that I am aware of) is www.fluidampr.com . They claim to have a product coming out within the next week for the 4G63-T.

 

[TracOwner]

Ok, I guess I'll just get another OEM pulley instead. Thx for the info.