Lightweight Aluminium Flywheel

[markjh]

My 986 feels like it is (over)due a clutch, probably flywheel and associated bits and pieces too- approaching 130k miles and never been changed as far as I can tell. Clutch has got heavier recently, although it's not slipping. External signs of what I believe is a slight RMS leak, and will be checking IMS too. 

My question is has anyone fitted one of the Single mass Lightweight Aluminium flywheels, I'm looking at the Design 911 one, if so what are your thoughts? I never 'track' the car, road use only, and other family members use the car so it needs to be drivable on a run to the shops. 

I saw a YT video where someone had put one in their 996 and he was enthusiastically talking about how the car revved more freely, which would be great, but not so great if it makes the car virtually undriveable at low speeds.

Many thanks.

[½cwt]

The drive train will likely be less refined losing the damping effect of the dual mass and also it will likely become much more easy to stall at low revs when manoeuvring and in slow traffic.  What do you want to achieve?

I ditched a lightweight flywheel with twin plate clutch on an import Impreza and went back to OE spec as it was a PITA.

Edited October 10, 2023 by ½cwt

[edc]

@map is one of the only active members with a light weight flywheel. Given your use of doesn't sound like it will be a good option for you. Sounds like you want usability rather than 'focussed'. 

[markjh]

I'm wanting to achieve a crisper response and for the engine to rev more freely, but not at the expense of the car being very difficult to drive at low speeds.

I've only driven a  BMW that had the DMF replaced with a solid flywheel, and in traffic it was terrible, but it was the owners track day car so it suited him.

If possible I was looking to get someone's opinion who has paid for one of these to be fitted and see what their real world experience is, rather than be influenced entirely by a YT video where you are never sure what commercial deal has gone on.

Here's  996 You Tube Video the bit about the clutch starts at around 22 minutes. 

 

[edc]

If you want a snappier throttle response then consider a remap as that will generally include adjustment to the throttle request maps. For better revving at the top end get some sports manifolds and perhaps some sports cats. 

[map]

9 hours ago, edc said:

@map is one of the only active members with a light weight flywheel. Given your use of doesn't sound like it will be a good option for you. Sounds like you want usability rather than 'focussed'. 

Yep - I have one and am convinced of their value in my use case. I use mine as a daily driver which has been commuted in London, tracked, Euro-toured and pootled to the max.

The oft mentioned willingness to stall isn’t a factor for me because the map was amended to manage that possibility. It’s important to bear in mind that this was part of wider changes to the car that included a full dyno mapping session.

At idle, with the clutch released and in neutral the car sounds like a bag of spanners being shaken - I like this but you may not.

There are suggestions that the lighter flywheel may damage the rotating assemblies because of harmonic vibration and the like.  Whether or not you’re OK with that possibility only you can decide. I am but then I have developed a pretty high threshold to this sort of thing.

I’m inclined to agree with the suggestion of a proper remap to allow the engine’s responsiveness by altering the throttle map 👇

9 hours ago, edc said:

If you want a snappier throttle response then consider a remap as that will generally include adjustment to the throttle request maps.

 

[T911UK]

Great on track or fast road use, no good for family shopping trips! Dont do it.

[MickH]

There are other things you can do that will not affect the usability of the car.  Saying that if my clutch went I would deffo up rate both Fly and clutch

 

Remap as mentioned

Underdrive pulley kit

Bigger plenum and TB

Exhaust

Induction kit 

etc etc

[Patt]

Cheapest and easiest way to "wake up" a 986 is the larger throttle body.  Even better if you get a re-map to compliment it.

I have had lightweight flywheels before and had no issues daily driving the car, however I also had the mapping adjusted shortly afterwards.

[ATM]

I have a LWFW in this. Its easy to live with once you get used to it. When I drive my standard 986 I find myself blipping the throttle a lot when pulling away in first because I'm still driving in LWFW mode. Which is obviously totally unnecessary. You can pull off in the standard car without any throttle and it won't stall. It definitely makes the car feel more lively but when I first got it I found it annoying. Go figure. Although the blurb I got with the car mentions a light weight clutch too so I can't be sure about that.

 

[bally4563]

I think you have had answered it already that other family members use it . If it was just yourself you could potentially live with any misgivings.

[markjh]

Thank you everybody for all the response and input.

I have now read the  @map full thread - too, what a great resource!! (this didn't show up when I searched before posting).

Although I'd love to try the LWFW I'll be sticking with the standard dual mass flywheel, there is no way the rest of the family who drive it would put up with the compromises (sounding like a bag of spanners at idle)..

Thanks again for all the help.

Regards

Mark

[½cwt]

Plenty of other trick that the family can cope with that will give you some of what you are looking for like the throttle body conversion and a re-map that will cost similar money.

[Ninesomething]

On the positive side the rest of the family won't want to drive it.....

Edited October 12, 2023 by JonSta

[pacificjuha]

I have the Aasco LWFW with Sachs sprung clutch plate (that Aasco recommends) adn it does not sound like a bag of spanners... I'd like it to sond like that, but purchased the sprung clutch due to recommendations from Aasco and several others who track tand use the same car on the street.

With equal lenght headers, 200cpi cats and free flow self made back boxes the rpm pick up is fantastic compared to stock 2.7 car. Have not yet done re-mapping, but will probably do so at the spring time (car still have to pass smog test with possible re-mapping...).

I do recommend the set up I have on my car. no issues at all on take off, just slightly more rpm's and let the fun start 😎

[map]

21 hours ago, markjh said:

I have now read the  @map full thread - too, what a great resource!!

@markjh Thank you - appreciate this 👍

In terms of sounding like a bag of spanners: this only happens when the car is idling, in neutral with your foot off the clutch. It doesn’t do it at any other time. That said it’s not for everyone - mrs_map ALWAYS asks if it’s broken…..🤷‍♂️

With regard to revs/pulling away - there’s no need for extra revs or specific clutch technique..

Bear in mind that the LWFW is only one lighter part on my crank assembly.

The pistons and rods are all lighter than factory with the overall weight of rotating parts (flywheel/crank/rods and pistons) over 8kg less (on the scales) in my 3.7 than it is in a 3.2.

With all this 👆in mind the fact that I just drive it is almost certainly down to the much lower rotating mass being managed in the mapping

@pacificjuha the “bag of spanners” seems to be a universal invitation for petrolheads to start a conversation - an unanticipated yet cool consequence of that very distinctive sound.  Your posts on your car always get my attention 👏

[pacificjuha]

2 hours ago, map said:

@markjh Thank you - appreciate this 👍

In terms of sounding like a bag of spanners: this only happens when the car is idling, in neutral with your foot off the clutch. It doesn’t do it at any other time. That said it’s not for everyone - mrs_map ALWAYS asks if it’s broken…..🤷‍♂️

With regard to revs/pulling away - there’s no need for extra revs or specific clutch technique..

Bear in mind that the LWFW is only one lighter part on my crank assembly.

The pistons and rods are all lighter than factory with the overall weight of rotating parts (flywheel/crank/rods and pistons) over 8kg less (on the scales) in my 3.7 than it is in a 3.2.

With all this 👆in mind the fact that I just drive it is almost certainly down to the much lower rotating mass being managed in the mapping

@pacificjuha the “bag of spanners” seems to be a universal invitation for petrolheads to start a conversation - an unanticipated yet cool consequence of that very distinctive sound.  Your posts on your car always get my attention 👏

Thank you @map, I do appreciate your vast knowledge that comes thru your posts always 👌

The 'bag of spanners' is in my opinion a spot on way of discribing the sound when LWFW M96 car idling on neutral gear with solid clutch plate. My friend has 996 GT3 where he has installed a LWFW / solid clutch plate that sounds just like that when idling on neutral gear 😁

[ATM]

4 minutes ago, pacificjuha said:

Thank you @map, I do appreciate your vast knowledge that comes thru your posts always 👌

The 'bag of spanners' is in my opinion a spot on way of discribing the sound when LWFW M96 car idling on neutral gear with solid clutch plate. My friend has 996 GT3 where he has installed a LWFW / solid clutch plate that sounds just like that when idling on neutral gear 😁

Yeah I'm not sure I'd say a LWFW is a definite no no.  I was getting frustrated with mine when I first bought the car.  All my driving is mainly inner city urban crawl.  I got used to it.  Sure I do still stall very occasionally.  But who cares.  It is nice when you get used to using it.  The car feels more peppy both on the throttle and also coming off.  I have been practicing my H+T action but I am a mere novice.  I even started dropping into 1st approaching some junctions or lights just to get used to it.  I think it might surprise some people behind me when they realise the car is slowing down a lot without aby brake lights.

 

I guess my point is any competent driver should manage just fine.  When I drive my standard car now with boat anchor Flywheel I find myself thinking it is a bit nanny-ish.

[Patt]

I struggled with the lack of feeling on a dual mass flywheel - often wheel spinning away from junctions and would only know when the roof was down.

The COBB throttle mapping on my 981 takes a lot of the frustration away.

I only really appreciated the difference last weekend when I took out a standard mapped PDK car at Thruxton whilst treating my niece for her birthday.

Even the "instructor" instantly translated my frustration on just the 2nd corner and hit the "fun buttons" and stuck it fully in manual mode (usually neither are selected and you are expected to only use 3rd & 4th gears in auto) If there was a LWFL option for the PDK I would seriously consider it too.  I'm now trying to justify to myself an LSD.

[ATM]

20 minutes ago, Patt said:

I struggled with the lack of feeling on a dual mass flywheel - often wheel spinning away from junctions and would only know when the roof was down.

The COBB throttle mapping on my 981 takes a lot of the frustration away.

I only really appreciated the difference last weekend when I took out a standard mapped PDK car at Thruxton whilst treating my niece for her birthday.

Even the "instructor" instantly translated my frustration on just the 2nd corner and hit the "fun buttons" and stuck it fully in manual mode (usually neither are selected and you are expected to only use 3rd & 4th gears in auto) If there was a LWFL option for the PDK I would seriously consider it too.  I'm now trying to justify to myself an LSD.

I thought PDK cars had a really light flywheel because the engine management does all the rev matching?

[Patt]

I don't follow - the manual also has rev matching and a Dual Mass flywheel.

The PDK picks up quick, but could be better.  If I want a burst of speed I have to drop the cogs as well as the throttle.

Or maybe its just me that needs re-programming....

[½cwt]

10 minutes ago, Patt said:

I don't follow - the manual also has rev matching and a Dual Mass flywheel.

The PDK picks up quick, but could be better.  If I want a burst of speed I have to drop the cogs as well as the throttle.

Or maybe its just me that needs re-programming....

Can't help thinking its the last of these?? 😉  We always want more when chasing performance...

[Patt]

I'm not chasing performance, I'm chasing feel and responsiveness.

[ATM]

57 minutes ago, Patt said:

I don't follow - the manual also has rev matching and a Dual Mass flywheel.

The PDK picks up quick, but could be better.  If I want a burst of speed I have to drop the cogs as well as the throttle.

Or maybe its just me that needs re-programming....

I believe all PDK cars from Porsche have a lightweight flywheel.  No need for Dual mass to smooth out shifts.  This is just for humans driving and switching cogs and using a clutch manually.  If an all automated system then better to have really light flywheel so the engine management can adjust the revs quicker if required.  A PDK can change quicker than any manual.

[map]

18 minutes ago, ATM said:

Dual mass to smooth out shifts

I was under the impression that the dual mass element provided damping to improve refinement - that's part of the reason for the "Bag O Spanners" sound on single piece flywheels (LWFW)

Happy to learn something else.