Light Weight Pulleys

[carew]

Could any1 tell me please how much do these parts weigh as standard?

Alternator Pulley?
Crank Pulley?
Power steering pulley?

Also could any1 tell me what bhp increase i would get for going for the light weight versions.

Thanks

 

[Willie]

This was tried on a LC with no benifit

Sorry can't tell you the weight differences

 

[carew]

Thanks for the reply mate.

I was just wondering because i saw the kit on the ecs website. Thought i could change them over while my cambelt gets sorted.

 

[karlosR]

i think i recall reading a post by bill (badger5) about the pulleys actually having an adverse affect on performance................ i could be wrong though

 

[Cupra Kev]

I know Issam at INA was saying that the crank-pulley shouldn't be replaced with a lightweight one, but the others were fine to replace - the crank pully is harmonically balanced or something which if replaced with a lightweight one on forced induction cars negatively affects performance - I'll try to find the thread that has this

 

[Cupra Kev]

Found it - http://www.seatcupra.net/forums/showpost.php?p=1968624&postcount=12

 

[carew]

I know Issam at INA was saying that the crank-pulley shouldn't be replaced with a lightweight one, but the others were fine to replace - the crank pully is harmonically balanced or something which if replaced with a lightweight one on forced induction cars negatively affects performance - I'll try to find the thread that has this

Thanks for bringing that up. So would replacing the other 2 improve the performance?

 

[Nautilus]

I revive this thread since I'm interested myself in the issue

The car is going to have the 60,000 kms (~37,000 miles) inspection at a stealership in about one month. Since it has made 4 years in March, the cam belt and water pump are to be inspected as well for signs of damage or wear - if they are in perfect condition I will change them around the 100,000 km mark.

As there will be some fumbling around the main crankshaft pulley, it's an opportunity to replace it with something better if available.

Crankshaft pulley is iron, weighs about 1.6kg (~3.5lbs) and according to people around the net it does incorporate a rubber harmonic damper.

This is how it looks (a Golf Mk4 version but still a 1.8T):

I for one fail to see the rubber ring which would do the harmonic balancer job...

This is a damaged one from a longitudinal 1.8T (an A4) and the rubber ring can be seen:

Aftermarket options:

Lightweight (not underdrive!) aluminium pulleys from ECS, Craven or other manufacturer. They do not incorporate a rubber harmonic balancer and weigh around 0.3-0.4 kg (0.66-0.88 lbs)

Fluidampr viscous-damping pulley from Fluidampr. This is how it works:

http://www.fluidampr.com/HOWITWORKS.htm

The 1.8T version weighs 6 lbs or 2.7 kg

From reviews we find out also that Fluidampr dampens the vibrations and helps the smoothness when revving up under open throttle almost to Rolls-Royce levels, or at least this is how it performed on large V6s and V8s.

On the other side, for torquey engines like a chipped 1.8T there is said lightweight pulleys are not suitable, the crankshaft twist would quickly wear out the bearings and previous to that engine smooth running would suffer. Tests made by members of this forum had proven there is no horsepower gain at all.

However, Fluidampr is heavy, 70% heavier than stock pulley. The basic idea behind lightweight pulleys was to free horsepower wasted by parasitic drag.

Will a Fluidampr decrease available crank hp and by how much?

Or crank hp would not be affected enough to feel the difference?

I'm talking first and fore most to people who had tried at least one of them or they are skilled in engineering or both. Balancing a high-revving engine is a very delicate job subject to great risks.

Thank you

Regards,

~Nautilus

PS this message has been edited after digging some info on lightweight pulleys

 

[crack5111]

ive just brought and fitted some lightweight pulleys. can say that i have noticed nothing.just wondering weather i should take them off if the crankshaft pulley should not be replaced or just take off the c/s pulley and leave the other two fitted?

 

[Shaunyboy]

Heres what can happen with a C/S pulley

http://www.seatcupra.net/forums/showthread.php?t=208928

 

[ibizacupra]

only a fool fits a lightweight pulley to the crank given what I have posted can happen as a consequence

 

[Shaunyboy]

In my eyes you dont need them on a turbo car, there more suited to N/A engines. The whole point is to reduce rotational mass allowing the engine to spin more freely, just changing the power steering and alternator pulley will no nothing to performance, as it still has a heavy dual mass on the otherside of the crank, so your hardly reducing the rotational mass. IMO spend your money else where.

 

[Willie]

Bill, even with the power your running do you still have the OEM pulleys?

 

[ibizacupra]

Bill, even with the power your running do you still have the OEM pulleys?

yes, stock pulleys, aside from crank pulley where i use a fluid damper one now
9000rpm, 35psi boost, >600bhp

 

[Willie]

Thats good enough for me then, cheers

 

[ibizacupra]

potentially an underdrive pulley on the alternator if I have voltage issues from overcharging or bearing issues on them, but no problems yet so fingers crossed its all good.

 

[crack5111]

only a fool fits a lightweight pulley to the crank given what I have posted can happen as a consequence

fair comment.
well if i had read ur post then i wouldnt have brought them in the 1st place. i only brought them as they were a cheap mod to see if they actually made any difference. but now i think i'll be taking them off.
just a quick question tho is my c/s pulley still dampered even though it does not have a rubber ring cheers (ibiza cupra )

 

[Nautilus]

Fitted a Fluidampr today to replace the stock crankshaft pulley.

Part no. 551201, for all 1.8T engines with 06A blocks and 4 bolt holes.

Provider: USP Motorsport

Cost: delivered and fitted, about 500 EUR.

Time to fit: about 1 hour if the car has to be raised on jacks, maybe 30-45 minutes if it can be raised by an elevator (very lowered LCRs on 19-20" wheels beware).

Differences from stock pulley: much heavier than stock pulley, much tighter fit over the crankshaft main bolt. Stock pulley could be removed by hand, Fluidampr needed a hammer tap to go the full way in.

Safety: Loctite on the 4 bolts, diagonal tightening by hand, diagonal final tightening by air drill.

Road test results:

+ much smoother idle (practically, even over the Powerflex dogbone mount and TT subframe mounts, the engine could not be felt running, had to look at the tachometer to be sure it runs);
+ slightly smoother engagement of the A/C compressor;
+ much smoother disengagement of the same A/C compressor;
+ much smoother acceleration at peak torque rpm (3000 to 4500 rpm in 3rd gear, WOT);
+ much less vibration transmitted into chassis at peak power rpm (5000-5500 rpm in 3rd gear, WOT);

- had no time and money to test on a dyno to see if it gives the ~3% hp increase other users reported;
- there is some small amount of vibration which escapes undamped at high rpm. It is smooth in operation, but not Rolls-Royce-like smooth.

~Nautilus

 

[Ronin225]

I'm glad you rate these fluidamprs highly as i decided to order one for my stroker build so will update when i fit mine too

 

[grahams81]

Hhhhmmm might have to get one too, suppose its piece of mind and im running a SMF aswell.