Lightweight Aluminum Crank Pulleys

[jirkipi]

Like I said earlier this topic could be discussed 'til the cows some home. From endless hours and miles of testing these units. There have been no problems to report at all. My LW crank pulley on the A4 1.8T has given me nothing but pure driving pleasure since the install some 4.5 years ago and 300,000km on the clock. And this unit has even better driveability than the A4. Smoother acceleration, better throttle response, pulls harder to redline, and is increasing the life of my accesories.
Just because it's not an OE Audi part, doesn't mean the quality and function isn't there.

example:

Why change your suspension?
Pros: For looks and cornering.
Cons: More and quicker wear on suspension components

Why get a bigger turbo or chip?
Pros: Because it's fun
Cons: More heat in the engine, replacing the clutch every year, more wear on your driveshafts

This would have more ill effects (long term) on your car than swapping the harmonic balancer anyday.

Bottom line...I have used LW crank pulleys on all my cars in the past 12, and not one has resulted in complete devastation. I understand this mod may be a bit new to some of you guys, but why would you knock something when you haven't tried it out or even seen it for that matter. I wouldn't try and pawn something off on anyone, especially someone driving a piece of Audi history.
My pulleys work, and work well.

It's your call guys, if you want one give me a shout!

[jirkipi]

At least 99% of the cars out there have some type of a harmonic balancer on the crank. I never said that all cars have a dual mass flywheel either.
This pulley wasn't made for all cars, just the ones mentioned in my original post. The dual mass flywheel takes up 99% of the harmonics in the crank.

[4WheelDrifter]

If the stock pulley is balanced in its own right, independant from the crank, then I can't see a problem with replacing it with another balanced pulley. So what if the pulley happens to be lighter?
How many people balance their crank when they change their clutch?
I'd have one, if I could afford it.

[robo]

so if you have single mass alloy flywheel you cant use this pulley then, or
if I do total rebuild and everything gets re-balanced would that be OK?

Sorry but this is bit too much information for me after long day
cheers

[RSCoupe]

My question is: What did Audi Sport do. They spent millions of dollars developing their racing IL5s, with every trick in the book to make them lighter and more powerful. Plus they could rebuild them every race. So, what did they do? If they had a pulley with the harmonic balancer built in, there was a d@mn good reason for it. And if you think you have thought of something that they didn't, you're kidding yourself.

[aelred]

I think what Steve H is trying to say is and I agree that there is nothing wrong with your pulleys, the point is if you are using such a LW pulley it will be used by some one trying to lighten the rotating mass of the moving components of the engine for power, response etc. and usually it will be done at rebuild and balancing point and I see nothing wrong with it. When manufactures balance engines is done to a much greater tollerance than a reputable engine balancer, parts can be up to 5 grms in tollerarnce in a mass production engine. When you have your engine balanced this tollerance goes down to within 1/2 grm.
The 5 cylinder engine is difficult to balance and there are only very few people that can do this. The crank, front pulley and flywheel are balanced together, 50% of the weight of the piston with rings, bearings and rods are added to the crank. If i had an engine fully balanced I would not change any of the balanced components in order to loose some weight. I have lightned flywheels by a lot and I will be honest the last one was miles out in respect of balancing I think it was 30 if not 50 grms, (this was not the original flywheel and proves the point) you should have seen the crank with pulley balanced trying to jump out of the balancing bed and that was only at 600rpm.

The five cylinder engine is balanced using a 50% factor, that is what Audi recommend is best for the multiplane crank. If the engine was balanced to a 0% factor life will be simpler as you could have all parts individully balanced (like on a single plane crank)therefore if you change items like the front pulley as long as it was balanced to a 0% factor it would not matter.
In dual mass flywheels the front pulley usually is not the harmonic damper, the flywheel is.
I personally do not see the point of changing the front pulley because is passed its sale by date, by this time the engine is probably out of date as well and probably a LW pulley will make little difference any how.
I would use one of these LW pulleys on a fresh build engine that is ready to be balanced.

[jirkipi]

That's a good question. I would love to know if they used the stock harmonic balancer. My guess is that they did not.
I'm not the first or the last person to think of making a LW crank pulley for the 5cyl. motor and never said I was. You think they thought of everything 25 years ago...there is nothing they would have done differently with todays technology. Please, you are the one that's kidding himself!
Either way you look at it all engines work pretty much the exact same way, the 5cyl. is no more special than a 4cyl. or V6
Do some research into how many race team (touring cars / GT) still use the stock pulleys on their motors.
NONE!

My question is: What did Audi Sport do. They spent millions of dollars developing their racing IL5s, with every trick in the book to make them lighter and more powerful. Plus they could rebuild them every race. So, what did they do? If they had a pulley with the harmonic balancer built in, there was a d@mn good reason for it. And if you think you have thought of something that they didn't, you're kidding yourself.

[jirkipi]

I wonder why nobody harps on you for running an Aluminum LW Flywheel. You took your stock 20+lb. steel flywheel and replaced it with an 9+lbs aluminum flywheel. According to Steve, you should have had your crank balanced
I have never heard of anything more ridiculous in my life!
The pulley doesn't require much balancing since it is being machine on a lathe, and not cast. We have been making Aerospace parts for jet engines for over 35 years, and very little is needed to 0+/- balance these very critical parts.

so if you have single mass alloy flywheel you cant use this pulley then, or
if I do total rebuild and everything gets re-balanced would that be OK?

Sorry but this is bit too much information for me after long day
cheers

[SteveH]

I wonder why nobody harps on you for running an Aluminum LW Flywheel. You took your stock 20+lb. steel flywheel and replaced it with an 9+lbs aluminum flywheel. According to Steve, you should have had your crank balanced
I have never heard of anything more ridiculous in my life!
The pulley doesn't require much balancing since it is being machine on a lathe, and not cast. We have been making Aerospace parts for jet engines for over 35 years, and very little is needed to 0+/- balance these very critical parts.

You obviously know a great deal about the balance factors on the 5 cyl motor. You appear to have missed the point, nobody has suggested your pulleys are out of zero balance.

[Fat Audi 80]

: popcorn smiley :

[porkkis]

Guys, think this through before buying!

I wouldn't want to spoil anyones business but IMO this is not the way to lighten rotating masses on a 5cyl. 4cyl -> no probs!

[S2central.net]

Ah yes - buyer beware on these. I'm no expert on 5-cyl dynamic balancing - but I know enough to say that it is an engineering task that I would only entrust to the most experienced machine shop with proven knowledge of our oddball engines.

I'm not against use of exotic / lightweight materials as they can make for a sweeter revving engine - but only when the appropriate dynamic balancing is performed by an expert in the art.

Paul

[Erikb]

I am busy with collecting parts for my rebuilt. For this rebuilt i bought new rods and I am looking for new pistons and a flywheel(probably the one jeffers sells). When I have all parts it will be balanced. I am thinking of buying such a LW flywheel together with the flywheel you will lose a lot of weight. But what will this gain and will it still idle ok?

[CHEN]

Thought i would throw my oar in, in my opinion you could change the pulley wheel for a lightweight on and in truth you probably wouldnt notice a difference. However I do side with SteveH must of us here would rather a job done properly! Fact is; you change either flywheel or crank pulley for a non-genuine part (like for like wont make a difference) the only true way to be confident that everything is in harmony is to check the balancing

[jirkipi]

It will idle just fine with the two components. One thing with the LW aluminum flywheel though...you will get a little bit of vibration at idle which is felt through the shift knob. You will not 'gain' HP/Torque, but you will not lose nowhere near as much when power gets transferred from the crank to the wheels!!! Think about it you will have freed up at least 90+% off the crank. Your car will rev almost as as freely as a 1000cc motorbike

Paul

I am busy with collecting parts for my rebuilt. For this rebuilt i bought new rods and I am looking for new pistons and a flywheel(probably the one jeffers sells). When I have all parts it will be balanced. I am thinking of buying such a LW flywheel together with the flywheel you will lose a lot of weight. But what will this gain and will it still idle ok?