Does anyone know where i can find the aforementioned product? I looked on the supported vendors and didnt see it, just curious if anyone knows where they are available. Thanks...

 

check out unorthodox they're devloping one for the cobalt

 

...why bother..its not a mustang.

id be very suprised if there were ANY gains at all from getting underdrive pulleys...probably do more harm then good.

 

the add a considerable amount of horsepower to the wheels. Plus i figure, how can lightening the working parts on a car hurt. Just makes them move easier. Less drain on the motor and what not.

 

Z-spec has a light-weight pully for $150 (I think it was $100 last month.) It's not an underdrive though. If you go to Unorthodox's web page, they state that 85% of the power gain comes from the weight savings of their pully, not from the fact that it's a little smaller.

Living in Tampa, I'd think that your a/c is important. I wouldn't want one myself for fear of losing cooling power (living in Louisiana.) All we're driving is the alternator and a/c - no powersteering. If a/c is not on, then all you're driving is the alt., which robs about 3-4 hp from your engine. Slowing it's rotation 20% will save .2 x 4 = .8hp max.

I think you would be looking at less than 1 hp gained by going to underdrive vs a stock size light-weight pully.

IMHO

 

thats the thing though...you WONT add considerable amounts of horsepower to the wheels...the "less drain on the motor" would most likely only be minimal...but the drain on your accessories may be considerable.

new engines are desisgned with efficiency in mind...so the underdrive pulley is probably as efficient as it is going to get.

this sort of "underdrive pulley" stuff was only useful on mustangs and old LT1 engines.

 

because most underdrive pulleys replace the harmonic balancer which helps to quell some of the vibration in the crank. Without this vital peice, the vibrations in the crank can lead to permanent damage including cracking a crankshaft.

 

..and add slack to the drive belt for your supercharger! Underdrive your alternator, and A/C compressor, great idea!

Underdrive pulleys are a waste of money for the 1-2 in horsepower gains. I would like to see a four cylinder dyno gain from an U/P, I wonder from where you are getting your numbers from?

 

Good point!

I've never heard of it cracking a crankshaft, but it will shorten your main bearing life considerably.

 

http://www.rsmracing.com

I think they have one that works for Ecotec's.

 

there was just a very informative thread about this in the 2.2 section, might be useful for those interested in this part to read all of that first.

 

Here is a picture of it:





Here is a description of it:

Lightened Billet Aluminum
Crank Pulley
Designed by Z-Spec as the lightest crank pulley
on the market for quicker revs and better
acceleration.

$150.00.

 

Ummm... cause we're in the 2.4L Ecotec section, and the kid's sig says he has a 2.4L SS.... and we all know how much we don't want to slacken the belt driving our massive superchargers.

 

thanks guys. So the overall consensus is that underdrive pulleys are not worth it. But would you agree that a crankshaft pulley(lightweight) would be a good investment. I read on another forum that the underdrive pulleys add anywhere from 6-8 whp, guess i heard wrong. What kind of difference will the crankshaft pulley make other than throttle response?

 

If you knew that you would reduce the life of your main bearings by half for 3-4hp would you do it?

Plus, if you decide later to add some serious power to the engine like turbo or nitrous, you could suffer a catastrophic crank or main bearing failure.

I plan on keeping my car for a while, so I won't be getting one.

But if it's just a lease that you'll be trading in soon, then it's up to you.

 

honestly i dont know how many ways it can be said...getting pulley's of any kind; be it lightweight, smaller, or both, will probably net you gains that would be so small you wouldnt even notice it if you dyno'ed...actually i bet you would get zero gain from something like this.

save your money...

 

alrighty, thanks guys. Good to know. Prolly wont do it then if it can do so much damage and wont net me decent gains. Appreciate the time you took to fill me in. This is my second car, my first being an 85 lebaron, so im just getting into modding. Since i have a car that isnt threatening to die on me everyday.

 

This is not underdrive, just lightweight

 

Yes, it is a crankshaft pulley. I thought that that's what he was referring to.

 

^^^
Well being that our stock pulley doesnt have an harmonice balancer on it will not hurt anything. If ya'll dont believe me I would love to take a picture of my stock pulley for you, so please everyone quite saying it's going to ruin his bairings because it wont!!! On some car's yes but not our's.

I bought one of the billet light weight pulleys the RSM one and i could notice a little gain and would rev a little faster but nothing crazy.

And as far as an underdrive pulley on our car I think it would be impossible to fit one. Because of the way it is designed you wouldnt be able to fit anything smaller on the block, it is really hard to explain but I will try my best. Where the pulley goes on the shaft there is an raised part on the block and it accctually goes inside of the inside of the pulley and if you were to try and put a smaller puley on it this raised part would acctually hit part of the pulley thus not allowing it to fit. Hope this helped.

 

Very interesting.

 

So then the lighten one will work with out the wear and tear everyone is saying?

 

so this lightened pulley is mine if thats the case, there is no negative effects just some faster reving which is always good

 

unorthodox does a good job with pullies...not reccomended as first mod seeing as it will only net a few horses, but if you want all oyu can get, go for it.

 

The U/D pulleys we carry ASP [ not sure if they have on for the Cobalt's yet] Are all balanced will not CRACK the crank [ Thats ridiculous to say . if something like that happened it was because someone over tightened the Crank bolt] . Please don't misinform people if you have no real knowledge about the products . If they make one for the 2.4 I would bet you would get 6-8 hp to the wheels and a big increase in throttle response. We have seen 11whp on our LS2's . I will find out if they carry on to fit the 2.4 or 2.2 . As far as hurting you accessories it will do the opposite by slowing them down they will last longer . Worst case would be if you didn't change the alt pulley you would go through batteries every 2-3 yrs instead of 5-6 .