Underdrive pulleys [ merged 1/6/07]

[larryd]

Worth it or not? I'm thinking of going with the AEM tru-power pulley kit. Anyone used them?

 

[syrushcw]

2 questions. First do you still have that risk if you use accessorie lightened pulleys or is that only a crank pulley thing? Second I've read in a thread bout a year ago t hat there is a lightened dampened crank pulley does anyone know who manufactures it?

 

[clockworktoy]

If i were you i would throw that pulley in your garage or sell it, ive seen people post horror stories when they use unbalanced pulleys.

 

[syrushcw]

My engine was actually balanced with this pulley at the machine when I got all the work done.

 

[1992awdlaser]

It's is not about the assembly being balanced. It is more for when the crank twists due to the power stroke. The pulleys like water pump or power steering won't cause the problem like a solid crank puley.

 

[4g63Powered]

First do you still have that risk if you use accessorie lightened pulleys or is that only a crank pulley thing?

Alot of the lightened accessory pulleys are also underdriven, which is something else to look out for.

 

[folly6767]

Don't bother installing it, not worth the risk. Sell it to some tool on E-bay.

 

[weegee411]

I'm planning to purchase an underdrive crank pulley for my 7 bolt (yeah I know not smart for long run) but I have a DD. Has anyone installed an Ebay underdrive and how good does the car perform after being installed? Or is unorthodox the way to go?

 

[Spoolin18]

I would save the money and spend it on something worth while, unless you're decked out with goodies as it is. Plus its hard on everything.

 

[snowborder714]

Is this for a turbo or N/T?

I can't speak for the N/T application, but that'd be a bad idea if it's a turbo. It's called a harmonic dampener for a reason. Please do a search for this and you'll find out why using a solid metal pulley is a bad idea.

 

[rEclipserGST]

I'm planning to purchase an underdrive crank pulley for my 7 bolt (yeah I know not smart for long run) but I have a DD. Has anyone installed an Ebay underdrive and how good does the car perform after being installed? Or is unorthodox the way to go?

Research more before you buy that. Its lighter weight. Which means it in turn, puts more stress on the other components that are revolving around the belt. Basically it will break other things in due time. You have to upgrade a few of those cranks/pulleys/etc. if you want to go that route. Use the search button. Search for a kit. Or just go with a Fluidampner.

 

[nlzn]

A lightweight aluminum pulley that is balanced with the assembly can be a good addition to a drag car.

For a DD search some here, I'm sure you can find some bottom end horror stories that have resulted.

 

[weegee411]

I was planning on doing the whole system I was just wondering if ebay with a crank pulley is the way to go with a turbo application. but I heard from a reputable shop in Colorado Springs that leaving it stock causes more stress on the bearings of the pulleys because of the extra weight.

 

[Spoolin18]

Yea dude, you're just asking for it if you use that pulley. It will unbalance your crank, which in turn will cause internal damage.

 

[weegee411]

wait ok so if I have less weight on one side of the crank and its not balanced evenly it will wear more of the internals on the passenger side?

I'm sure more than a couple ppl have installed it and have seen no problems, is it like a random problem like crankwalk which you always hear about but hardly ever actually see?

 

[Spoolin18]

Its none of my buisness, but why are you wanting to use it? The risk far outweighs the gains.

 

[weegee411]

Its a weekend driver for the track and some night driving. I have pretty done everything else. but wouldnt boosting more have the same wear?

 

[Spoolin18]

To some degree=) but if the bottom end is unbalanced, it leads to enevitable bottom end failure

I just don't see doing it at all unless you have alot of cash on hand. You would be lucky to pick up a few H.P, I doubt it would help your times. I WOULD NEVER DO IT. But good luck with whatever you do.

 

[FMFGSX]

Like everyone else is saying do a quick search. You'll some pictures of crankshafts that have snapped in half. I had a Megan Racing UDP for a while, didn't really notice any gains. Once I found that more and more people were having to replace motors because of it, I quickly went back to a balanced pulley. As for the rest of the pulley system there will be no harm in swapping everything else out.

 

[weegee411]

Yeah and boosting more actually goes through the head and piping etc so theres more risk there. Im installing the underdrive either way. It makes more sense to install the underdrive system and see 30 more horses and blow a bottom end then boost 5 more lbs and n risk head, turbo, etc. I was just wondering who's installed an ebay one and how good they ar balanced

I did a search and saw one story and other people saying they noticed a gain and havent had problems with installing the underdrive and no problems with crank on a 2g

 

[snowborder714]

Well, then install it and keep us updated on how everything holds up.

 

[weegee411]

will do boss. Ebay underdrive and unorthodox accessory pulleys

 

[snowborder714]

Just keep in mind, with it being underdrive, it'll drive all of your belt accessories slower than the stock rate.

 

[slowgsr]

run a fluidamper if your going to change it man.. Heck, underdrive pulley's will make no noticeable difference on your engine as far as power is concerned, life will be shortened.

 

[T is for TURBO]

Yeah and boosting more actually goes through the head and piping etc so theres more risk there. Im installing the underdrive either way. It makes more sense to install the underdrive system and see 30 more horses and blow a bottom end then boost 5 more lbs and n risk head, turbo, etc. I was just wondering who's installed an ebay one and how good they ar balanced

I did a search and saw one story and other people saying they noticed a gain and havent had problems with installing the underdrive and no problems with crank on a 2g

Yeah, and all of the bearing material that will be floating around in your oil system because of your newly unbalanced crank shaft isn't going to reek havoc on your head, turbo, ect.

Also, ONE story should not be enough persuasion to do something, especially when you have a grip of people advising against it.

But, do what you want. It's your car.

 

[dsm8883]

Yeah and boosting more actually goes through the head and piping etc so theres more risk there. Im installing the underdrive either way. It makes more sense to install the underdrive system and see 30 more horses and blow a bottom end then boost 5 more lbs and n risk head, turbo, etc. I was just wondering who's installed an ebay one and how good they ar balanced

I did a search and saw one story and other people saying they noticed a gain and havent had problems with installing the underdrive and no problems with crank on a 2g

30 hp sounds great to me, hell i am going to drain all of my oil out and try and get 5 HP. instal a junk crank pulley on your car but buy a honda first