Lightweight Crank Pully

[th3_f15t]

I have a cam belt change to do on my 6R and wondering if it's worth investing in a lightweight crank pulley at the same time seeing as it'll be exposed and being worked on.

Any reason not to get one?

[Tfsi_Mike]

I've read lightweight ones can have an adverse effect due to not being in sync with the harmonics of the engine.  There was a good read that helped explain it, somewhere.

I fitted the fluidDampr pulley to mine. Not lighter but is supposed to be a performance enhancer.

[AJP]

I think @Shoduchi tried one. IIRC there were potential issues. I'm not sure if he kept it or went back to standard.

[Shoduchi]

I researched and shared my findings in my topic build after being alerted of the potential dangers of fitting the lightweight pulley: http://www.mk5golfgti.co.uk/forum/index.php/topic,95592.405.html.

My final conclusion was this:

After testing more carefully my car now, it's my opinion that the lightweight engine pulley does make a difference. The engine revved quicker from lower RPM with it fitted. Just to share my experience. I don't regret returning to stock since I value more my engine's lifespan.

Its more dangerous to engines that run for long periods near the redline. For daily use without pushing too much the engine I bet the problem wouldn't happen before the end of the lifetime of the car. Since I pretend to go to track days 3-4x/year I won't risk breaking my engine. The OEM pulley has a rubber layer to damp the harmonics of the injection at high rpm.

[pudding]

Someone posted on the TFSI FB group over the weekend it was the best £100 he's spent on the engine.   GFB pulley.   So that's 2 positive reviews so far 

Did you notice any increase in vibrations the guys using GFB and Fluidampr pullies?

I think it would be a bit more beneficial if added to a lightweight flywheel to further reduce rotational mass, but the rattles would do peoples heads in!

I did all that years ago and I thing I noticed as well as quicker throttle response was improved engine braking.

[Shoduchi]

No vibrations that I've noticed. Just quicker accelerations. No significant differences on engine braking, maybe just a bit more than before if you really pay attention to it.

Not damping the injection harmonics and thus not preventing engine damage did my head and decided to return to stock.

[pudding]

No vibrations that I've noticed. Just quicker accelerations. No significant differences on engine braking, maybe just a bit more than before if you really pay attention to it.

Not damping the injection harmonics and thus not preventing engine damage did my head and decided to return to stock.

Although damage may not happen, I think I agree with you in that I would rather have peace of mind than slightly improved throttle response.  It's just one of those bad luck things that would break on the way to work, or on a long road trip 

[Shoduchi]

For whoever didn't check my build topic, I'll leave this link that Dan_FR shared with me, that convinced me that it was better to not risk damaging my engine when revving it to high rpm on my track days: https://www.facebook.com/JNLRacing/posts/1141770932518180.

About OEM crank pulleys:

They are designed to cancel out secondary harmonics from combustion cycle. Remove them and the big end bearings will fail over time especially at high rpm. Will damage journal but not snap/break Forged crank from can engines.

Audrius Bagdonavicius:
If engine will be balanced with light weight pulley, this won't happen.

JNL Racing:
Unfortunately it still will with this particular type of engine and many of the vag range as you can't balance for secondary harmonics from combustion cycle. Look at the 4.2ltr v8 that came in the tvr's. Sit at exactly 80mph on motorway and the crank would snap along a mains journal. Perfectly balanced crank with no harmonic dampener.

[th3_f15t]

All a lot of good information there... I will likely stick with my original plan of fitting the Fluidampr when I totally build my TFSI engine in the future. For now I shall save the money.

[pudding]

Interesting reading on the fluidampr - http://www.golfmk6.com/forums/showthread.php?t=94020

[Shoduchi]

Interesting reading on the fluidampr - http://www.golfmk6.com/forums/showthread.php?t=94020

I've read this when I searched about lightweight crank pulleys. I just didn't like its price...

[Shoduchi]

http://www.akstuning.co.uk/fluidampr/256-fluidampr-engine-damper-20-tfsi.html

£ 382.80

 

[pudding]

Expensive!  What did you think to the +20hp gain from using it?  Seems a bit far fetched to me?!

[Shoduchi]

Expensive!  What did you think to the +20hp gain from using it?  Seems a bit far fetched to me?!

5-20 HP. They say it depends on the global hardware setup. I wouldn't expect that much gain or the power upgrade would justify the almost £ 400. I've spent that on my CAI...

[Shoduchi]

I agree with this comment:

NeoSA:
In my view this product is recommended for anyone who wants 5-10 more HP running K04, or someone that's running a BT setup that wants to protect the engine a bit more.

http://www.golfmk6.com/forums/showthread.php?t=94020&page=17