Lightweight flywheels

t-tony

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There was a member on here who went this route with his M44 1.9 to get shut of the DMF. He had it made himself but never got round to fitting it as he went abroad working.He was going to have it fitted for him but he left the forum under a bit of a cloud before it happened.

Tony.
 

Pingu

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Consider instead, if people just need to lose some weight,
far better and much cheaper.......=))
If you are thinking that a lightweight flywheel is just about losing mass, you really don't understand the concept.

Two flywheels could weigh the same, but accelerate at different rates.

A "lightened" flywheel is all about designing the flywheel so that it can accelerate faster. It is nothing to do with the mass of the flywheel. It is all about moving mass towards the centre.

Start at 1:03. Both of these have the same mass...

 

Pingu

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Did it make a noticeable difference?
Yes.

Remember that you are making TWO changes to the design. One is lightening the flywheel and the other is removing the damping provided by the DMF.

A lightened flywheel is one of the biggest changes that you can do to allow a car to accelerate faster.

The downside is the replacement of the DMF with a solid flywheel means that ALL the engine vibrations are transferred to the gearbox WITHOUT damping - so your gearbox will rattle. Mine isn't too bad, but it is noticeable when parked next to another.

Ideally, there would be a lightened DMF available - but there isn't.
 

Dino D

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There are a lot of e36 328 with this type of mod and I believe they are identical box to the Z3 so looking at those might yield more options than a ‘Z3’ specific item.

I believe the e34 M5 set up is a good replacement for a 328 and a popular mod.
I cannot remember exactly the deal but I think it’s give the benefits with less of the drawbacks.
Nonetheless it’s on my eBay watchlist =)):
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/372194520369

I’m sure I’ve also read about using a 325 clutch kit which only needs a small bit of machining to work on these. Nothing wrong with my clutch, even after 130ish k miles but no harm in researching just in case eh?:whistle:
 

Pingu

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it was a joke, professor..... =))
Most people who think about lightened flywheels as saving weight, it is more like an ice skater pulling their arms in so that they can spin faster.:thumbsup:

The lightened flywheel that I fitted has around 13% less MMI than standard. This is my thread from "over the road"...https://www.zroadster.net/forum/viewtopic.php?t=42001

This doesn't mean that the car can accelerate 13% faster, it just means that the clutch can accelerate 13% faster - but every little helps:)
 

Pingu

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Nothing wrong with my clutch, even after 130ish k miles but no harm in researching just in case eh?:whistle:
That's exactly what I do. I wait until something needs to be replaced and then replace it with a better part. A standard clutch is £500, a lightened clutch is £850, so it's only £350 to upgrade:D
 

machine monkey

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I have a UUC kit in mine. I haven’t done many miles. But I haven’t noticed any extra rattles. It revs so quickly now it great. For me it’s transformed the m54 in my car from a quality saloon car engine. Into a sports car engine.

It’s much more of a leg workout though. I tend to take it out of gear st the lights now instead of leaving it in gear!
 
C

cameron.white

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It's not just lightness but also the fact that you are going from a dual mass flywheel to a solid single mass one.

so, far i realized. but may be it can be wrong perception.
 

Pingu

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It's not just lightness but also the fact that you are going from a dual mass flywheel to a solid single mass one.

so, far i realized. but may be it can be wrong perception.
A DMF is a very good system for the average driver. It dampens the power delivery from the engine to the gearbox. This means that poor clutch operation can be made smoother. It also means that the pulses from the engine can be dampened, thus allowing the gearbox internals to be lighter.

The downside is that a DMF has a high mass moment of inertia (MMI) because it is effectively two flywheels.

A better compromise would be a clutch similar to a motorbike clutch (several sandwiched clutch plates in a very small MMI package). If it's good enough for Formula One, it should be good enough for good enough for us. The downside would be wear rate. Would you be willing to change a clutch every 5,000 miles for the extra performance? I would if the performance was worth it.

Swings and roundabouts.
 

the Nefyn cat

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If it was as easy as the average motorcycle clutch to change it wouldn't be a problem. But it wouldn't be that easy without a drastic change to the basic car layout. Anybody else ever changed a clutch on some of the older Vauxhalls where you could pull the primary shaft out of the clutch completely and then drop the clutch itself out of the bellhousing? Damn clever idea, which is probably why they seemed to drop the idea.
 

t-tony

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Very true mate, change a clutch in 45 minutes. Mind you I could do a Chrysler Alpine clutch in an hour, or a gearbox swap in 20 minutes (in a car showroom, on a main street, 3 cars back from the window).;)

Tony.
 

Pingu

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Quik Fit would be chuffed t'bits if they went for the multi-plate option:). The thing is that it would only be viable for high performance cars whose owners can tolerate the gearbox noise, clutch "characteristics" and general lumpiness. It wouldn't be a very refined vehicle - but I'd love it :D. Mine accelerates too fast for the tyres in the wet now - God knows what it would be like with a super-light clutch.

I've never seen the primary shaft idea, but it sounds like a good one.
 
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