underdrive pulley!!! anyone got em yet.

[dieyoung17]

Recently my 350z IDLER pully went bad so I was looking on EBAY for 350z pulleys, I came across these Light weight aluminum racing underdrive pulleys for 350z. All 3 for like 80 bucks. The idler pulley itself cost 88+ in dealership. Im kind of skeptical about this...The seller claims that due to less weight of the pulleys more HP will be gained, Plus shorter belts have to be used, since the aluminum pulleys are smaller then the stock pulley. So I was wondering instead of buying just the idler pulley for like 90 bucks, why not just buy these pulleys for less then 90. What do you guys think?/say. thanks

[brickyardz]

Your looking at 2 completely different things. The idler pulley is usually the one putting tention on your belt. If that is bad and needs to be replaced you should get it done. Getting an underdrive pulley set will not include an idler pulley.

The underdrive pulley set you mentioned replaces the crank, altenator and water pump pullies. It is true that by making them lighter than stock you have less weight on the crank and it does increase HP. Underdriving the other pullies (making their diameter smaller than stock) does also add some hp but can cause problems if you have aftermarket stereo equipment that is sucking a lot of power. The under driving will produce less power at lower rpms because the altenator isn't turning as fast.

Most of the power gains are in the lightened crank pulley. One day I plan to add these but you can also get a set with all standard sized pullies, no under driving, so stock belt size is maintained and you don't have power issues. The amount of hp you gain from underdriving is minimal so my choice, when I do it, will be to maintain stock size pulley and just get lighter ones.

[BonesZ33]

^^ great info brickyard

[Zzoned]

I got unorthodox racing pulleys....kick ass i love em

[BonesZ33]

Originally Posted by Zzoned

I got unorthodox racing pulleys....kick ass i love em

feel any difference? is it worth the $$?? thanks man

[dieyoung17]

Originally Posted by brickyardz

Your looking at 2 completely different things. The idler pulley is usually the one putting tention on your belt. If that is bad and needs to be replaced you should get it done. Getting an underdrive pulley set will not include an idler pulley.

The underdrive pulley set you mentioned replaces the crank, altenator and water pump pullies. It is true that by making them lighter than stock you have less weight on the crank and it does increase HP. Underdriving the other pullies (making their diameter smaller than stock) does also add some hp but can cause problems if you have aftermarket stereo equipment that is sucking a lot of power. The under driving will produce less power at lower rpms because the altenator isn't turning as fast.

Most of the power gains are in the lightened crank pulley. One day I plan to add these but you can also get a set with all standard sized pullies, no under driving, so stock belt size is maintained and you don't have power issues. The amount of hp you gain from underdriving is minimal so my choice, when I do it, will be to maintain stock size pulley and just get lighter ones.

IM sorry but what do you mean by 2 different thinggs?? the idler pulley is just a pulley itself, and the z has a total 3 pulleys,,plz correct me im wrong. the auction is also offering 3 pulleys.

[Zzoned]

The butt dyno says hell ya lol just my complaint is that for some reason when my headlights are on and my heater at the same time...or ac.....the god damn thing squeeks like the tensioner if messin up but also everyonce in a while my stupid belt squeels to....ive only notticed it about a year after i put it all together

[Zilverbullet]

i was in the market for the unorthodox pulleys also, think im gonna get them after i do my clutch and flywheel but what brick was saying that the kits only come with the crank, alternator, and water pump pulley the idler isnt included, from all the kits that i ever looked at those 3 were the only ones that were included

[BonesZ33]

Originally Posted by dieyoung17

IM sorry but what do you mean by 2 different thinggs?? the idler pulley is just a pulley itself, and the z has a total 3 pulleys,,plz correct me im wrong. the auction is also offering 3 pulleys.

the puley set replaced 3 pulleys... the alternator pulley, the water pump pulley, and than the crank pulley... the idler pulley is is a whole nother pulley by itself... its purpose is to bring the belt in a different direction and on some cars it is used to tighten the belt so there is tension on it

it is a pulley by iself and isn't attached to anything.. the kits you are looking at woudln't fix the problem you have.. you need a new idler pulley..

[BonesZ33]

Originally Posted by Zzoned

The butt dyno says hell ya lol just my complaint is that for some reason when my headlights are on and my heater at the same time...or ac.....the god damn thing squeeks like the tensioner if messin up but also everyonce in a while my stupid belt squeels to....ive only notticed it about a year after i put it all together

what were the numbers hp/tq gains ?? thanks dude

[brickyardz]

Originally Posted by dieyoung17

IM sorry but what do you mean by 2 different thinggs?? the idler pulley is just a pulley itself, and the z has a total 3 pulleys,,plz correct me im wrong. the auction is also offering 3 pulleys.

The Unorthodox Racing 3 piece pulley set comes with a crank, altenator and water pump pulley. Most other 3 piece pulley sets will include the same parts. There is no idler pulley included in the set. The idler pullies apply tenetion to the belt to keep it tight while on the car.

Checking the service manual there appears to be 3 idler pullies. 1 for the AC compressor and 2 on the altenator side. There are 2 belts on the Z. If you have determined your idler pulley is bad make sure you know which one. Buying a pulley set will not solve your problem of replacing your bad idler pulley. You will still need to purchase that seperately. I would also be careful with no name brands here. You are talking about reducing the weight on your crank and if the pulley isn't balanced properly you will get vibrations and other problems as you increase speed.

The bottom line is what your looking to purchase will not provide you with the idler pulley your looking for to fix your problem.

[DChris14]

Originally Posted by dieyoung17

Recently my 350z IDLER pully went bad so I was looking on EBAY for 350z pulleys, I came across these Light weight aluminum racing underdrive pulleys for 350z. All 3 for like 80 bucks. The idler pulley itself cost 88+ in dealership. Im kind of skeptical about this...The seller claims that due to less weight of the pulleys more HP will be gained, Plus shorter belts have to be used, since the aluminum pulleys are smaller then the stock pulley. So I was wondering instead of buying just the idler pulley for like 90 bucks, why not just buy these pulleys for less then 90. What do you guys think?/say. thanks

I bought an undersized pulley which means a smaller crank pulley....... in size that is. Then I ended up buying the Unorthodox Racing STOCK sized pulley 3 piece set. With the undersized pulley attached, the car's Alt pulley was not turning as much, therefore not producing the electric current needed to run the car's AC, etc... NOW if you are tracking your Z then you might want to get the undersized pulley, but if this is your every day car and do a lot of city driving then you definitely want the STOCK sized pulley.

I would take BrickyardZ's word as gospel, he knows his ............ well you get the picture.

[dieyoung17]

alright thanks alot guys, i would stay with stock size, until i find ones that are light weigh and stock size, i would get those.

[RockStar350Z]

Dopes anyone know if they are worth the money tho??

[SuperMiguel]

Unorthodox Racing $400 for about 10hp maybe but i guess when it gets to pullleys is not about the hp is about how fast it rev up

[toby22]

Just ordered a UR underdrive pulley. Hopefully i wont get the problem some are getting with them Cant wait

[SmoothZ]

Man, I've had a light weight pulley for years.... sitting in my garage. I just never got around to installing it. I had one on my 300ZX and loved it. I should really make a concerted effort to put it on this year.

[white350zboy]

I'm going to get a pulley set soon. Either a Stillens set or UR's set.(3 pc) Dont be cheap and only spend like 90bucks. Thats just a quality problem waiting to happen. Good luck man!

[toby22]

I just got the ur underdrive crank pulley used for $50 shipped with the belts. Im not concerned with all that unnecessary bling i just want performance. THe thing that pisses me off is that i might be going F/I this summer (Supercharger) and i wont be able to use the pulley