Aluminium flywheel?

[Pat D]

034 have advised me that they have an issue supplying a steel flywheel and have recommended I use an aluminium instead

The build is a stroker which will be mainly street use and aiming for around 600hp. Any thoughts & experiences with this set up?

[JP]

I'm currently running their aluminium rs2 flywheel with a spec stage 3+ and 255/35/18 Federal 595 track tires on 570hp with a stroker although allreasdy bored with that so waiting for new turbo. Grippy as hell in both wet and dry with no clutch slip so far other than in the initial bedding in process when I took it straight to the race track as I was impatient not actually slipping when launching but in 5/6th on the way there on wot

my friend is running 750+ on his rs4 with an aluminium fidanza flywheel and same stage 3+ clutch.

My only issue to date is although the clutch flywheel combo is a really nice and driveable and feels completely stock it struggles to match engine to box speed at 8000rpm for a quick 1st to 2nd as the rpm drop is so big on our 6 speed box's, all other gears are fine as a smaller rpm drop. Whereas when I had the triple plate clutch on there with an even lighter flywheel it was butterey smooth 1st to 2nd but a pig to drive in any sort of stop start situation.

[Lloyd]

I currently have a SPEC aluminium flywheel fitted to my car.

Technically, it's aluminium with a steel insert for the clutch contact patch. It weighs just 4.5 Kg. To compare, my RS2 dual mass flywheel weighed in at a mighty 14.1 Kg!!!! A standard 3B flywheel is 10.4 kg and these can be safely lightened to 8.8 kg.

The massive difference in rotating weight is immediately obvious whilst driving. When accelerating WOT in second and even third, the car races away like a scalded cat. It makes a big difference. As you go into higher gears the effect is less noticeable.

When down shifting, you can rev match much more easily as a quick blip on the throttle quickly raises the engine's rpm. With the dual mass, it's much slower and harder to do accurately. Clutch feel, is I expect the same as with any single mass flywheel. Much more direct and needing a touch more finesse vs a dual mass to be smooth. I certainly prefer the more direct feel.

On the downside, it's noisier and you feel some minor vibration with the aluminium flywheel vs. to the dual mass. Specifically, around the 2000 rpm mark it's noticeably harsher, you can hear some gearbox chatter (hard to describe) and feel it generally. By 2500 rpm it's almost all gone.

At rest, you can occasionally hear some chatter which stops as soon as you touch the clutch. For a car that is a daily driver and used mostly on the road, I'm not sure that it's the optimum choice for everyone. Steel is after all much better at damping vibration than aluminium.

Unexpectedly, I also found that the point of resonance for a 3" exhaust system dropped significantly from around the 3000 - 3500 rpm mark to the 2000 rpm mark.

Net result, driving around town is not the nice n' smooth quiet experience it once was, with chatter and exhaust focussing at the same point. On the flip side, once out of town, you very rarely hit the noisy spot as RPM is above 2000 rpm.

If your car is a mostly a daily driver, I suspect the best all round compromise is to fit a lightened 3B steel single mass flywheel.

EDIT: Having re-read your aim of building a 600bhp monster, I doubt very much this will be a quiet, refined daily driver so yeah, why not go for an Ally flywheel?

HTH

[Pat D]

Thanks for the input. Think I'll go with the lighter ally flywheel. The car won't be a daily driver so I'm not too fussed if drivabilty is slightly compromised. The clutch I'm recieving is the Spec 3+ with the 5+ dual spring pressure plate. It hopefully won't be too much of a thigh builder

[Jamo]

Why have you gone with a spec clutch? IMO go Sachs or southbend
Too many reported spec clutch failures

[JP]

My Sachs race clutch got annihilated with just 520hp destroyed it and chewed the flywheel. No such issues with the stage 3+.
I personally still think most spec failures are down to people not refacing the existing flywheel so reducing contact area or buying the incorrect product for application. As a stg4 and stg5 handles less power than a 3+

[here2learn]

hello just to let you know there is a steel flywheel. made by company called big daddy they are billet steel. My friend at saxon motorsport recommends them as he uses them on his builds. possiblY contact them look at a group buy as my starter ring gear has detached.

[Pat D]

Why have you gone with a spec clutch? IMO go Sachs or southbend
Too many reported spec clutch failures

I wasn't aware of such failures. I'm hoping I won't have any then
I don't intend on having many redline starts from stand still so hopefully things should be ok.