lightened flywheels - where to get one from?

vwmk3jon · January 06, 2009, 06:41:45 PM

Missed out on the one Pete had up for sale and i'd like to change afew more bits and pieces on my car to get the bhp up abit.

Any ideas where to buy one from now PSD has ceased trading?

breadman · January 06, 2009, 07:29:55 PM

Jon, you don't need to buy a lightened flywheel, although specific racing lightweight ones are available - at a premium! Their life span isn't the same as an O.E. part either.
Any decent engine machine shop will be able to lighten your existing one. Looking at the back of the flywheel, material is removed from inside the outer "hub" part of the flywheel, adjacent to the ring gear land.
Obviously you shouldn't remove too much material because it can weaken the structure of the flywheel itself. However, the machine shop should (hopefully!) have plenty of experience in this type of work and know what is a "safe" amount to machine off.
Last time I had one done they only charged me 1 hour labour - £30 or so IIRC?
It won't make any extra power having it done, but it does help the engine rev up quicker improving throttle response and reducing the rotating mass.

Robin · January 06, 2009, 09:32:39 PM

PeteG40 has one for sale.

PeteG40 · January 06, 2009, 10:06:33 PM

its sold

Dont forget they need to be balanced on a crank too - if unbalanced will shake the shit out of the engine

pete

hayesey · January 06, 2009, 10:51:55 PM

they need to be balanced but it doesn't have to be done on the crank (although in an ideal world you'd get the whole assembly balanced as one). PSD just used to supply the flywheels ready to bolt on.

PeteG40 · January 06, 2009, 10:55:37 PM

yeah but they balanced em on a stock crank, which was better than not... or was steve telling porkies?

giorgio · January 06, 2009, 11:45:25 PM

Quote from: PeteG40 on January 06, 2009, 10:55:37 PM
yeah but they balanced em on a stock crank, which was better than not... or was steve telling porkies?

in retrospect probably the later

hayesey · January 07, 2009, 09:23:27 AM

Are you sure VW assembled the whole crank and flywheel and balanced it as a whole? For every single engine they made?

It's the ideal situation but I doubt it was done at the factory and also, who does that after changing a clutch? A new cover plate and clutch plate adds to the rotating mass too and can upset the balance as much as a flywheel.

PeteG40 · January 07, 2009, 09:54:03 AM

well vag probably didnt - but then they probably designed them uniformly enough to not need balancing, as clutches would be i dare say. But skimming some metal off the back of a flywheel might upset its original balance....

Not saying it would if done uniformly, but it might.

hayesey · January 07, 2009, 10:36:11 AM

yeah the engineering shop should certainly balance the flywheel when they've done it but I don't think it's necessary to get the whole crankshaft assy balanced which is what I thought you were saying.

The cranks are balanced individually from the factory, there are drilled holes in the counter balances where they've taken metal out to balance it.

PeteG40 · January 07, 2009, 12:41:41 PM

i was saying balance on a crank - apparently psd used to... i dunno i'm an engineering newbie

hayesey · January 07, 2009, 01:06:20 PM

psd never asked me to send them my crankshaft when I bought a flywheel from them. Totally pointless doing it on another crankshaft.

PeteG40 · January 07, 2009, 01:07:42 PM

unless each std crankshaft was same balance..

hayesey · January 07, 2009, 01:45:28 PM

well they are all supposed to be balanced so should be the same but there will be tolerance levels meaning small differences between different ones, and then take wear into account.

PeteG40 · January 07, 2009, 02:00:45 PM

oh well at least we had a debate about it

haha