Rattle my teeth out or drive like gran? Flywheel conundrum
 

Dear sirs and madams,

I've got a 2003 WRX PPP (265bhp) and use it around town most of the time – I'm going to get an Exedy pinkbox/organic clutch and am thinking about fitting a delightful 6kg flywheel while I'm at it.

However, I've read all the related threads on the whole of the interweb, and there seems to be totally split opinion on flywheels :Suspiciou. Has anyone who drives like a normal sedate slow person 90% of the time (but who would like better throttle response) moved from stock to lightweight flywheel?

I drive like a normal human with kids in the car all day, but thrash it and launch it to death like an electric unicorn after sundown; is the lighter flywheel going to increase wear on the rest of the drivetrain, increase noise in the cabin and generally be more of an effort to keep it from stalling at the lights..?! Pulling away slowly without stalling at what, 2,000rpm? 3,000? I normally launch at 4,500rpm - will it be more like 5,000? 6,000?!?!

I should add, it is a lovely car, and when it becomes legal to have two wives, the Subaru will surely move into our bedroom and I shall love it and caress it like the dirty beast it is.

With very kind regards,
Samuel.

EDIT: If you're looking into a similar thing, I did it in the end, here's the conclusion: https://www.scoobynet.com/drivetrain...-findings.html

.

Just get the existing flywheel skimmed (or exchange for pre-skimmed) for the new clutch. It's not a competition car. You could regret the possible rougher idle, clutch judder, easier stalling, geartrain rattle etc, etc. Not the best mod for a road car.

JohnD

My AP organic clutch and exeddy flywheel are fine together, maybe another 200 rpm to pull off, but you soon get used to it.

I'm no physics master but i'd of thought the lighter flywheel would mean less load, on the engine at least, which could possibly mean increased load on the drivetrain as more juice coming from the engine and less of a cushion from the lighter flywheel.:wonder:

It is however IMO one of the best mods you can do for responsiveness, i'll be chucking mine into my blob wrx ppp soon.;)

^ Thanks for the responses, but they sort of cancel out... as ditchmyster owns a car with a lighter flywheel I'll take his word for it - 200rpm difference? Is that all? What exxedy flywheel do you have? Cheers.

i found i had to drive in a lower gear when i fitted my lightened flywheel, e.g. forget pottering about at 30mph in fourth (or even third).

The car felt unhappy under 2500rpm IMO.

I think it's a 6kg but i'm not 100%, but it is important to match the clutch, Iv'e heard the exeddy pink box doesn't go to well with any lightend flywheel and is a judder monster.

Someone I trust said recently the AP organic is the way to go, but I already had mine so it just confirmed my choice.

Fashions come and go on here and the exeddy pink box is in fashion at the moment, when I did mine the AP organic was the one and I have no complaints.;)

Just to add for balance, this was on my STI Type r running 320bhp and was mapped with it on, so I think that may make some difference, but i'll be fitting it to my Blob soon as it's only done 10k and the Blobs clutch has seen better days @92k

I swapped my fidanza light fly for a standard one. Not only did I prefer the way the car drove but it also rid me of the common vibration/rumble on rundown.

Well done matty.

So that's the OP head fcuked then.:lol1:

Choices, choices.:lol1:

:lol1:

Do they actually have any effect on performance?

Less rotational mass if that's a word, :lol1:

Basically yes.:lol1:

As with most things performance car related "less is more".;)

Made a significant difference in my opinion, was very noticeable the motor spun up a lot quicker and more responsive, you basically get more of what the engine has to offer sooner because it's not working so hard to turn itself, standard flywheel is around 11kg ah fink :wonder: well worth 300 sheets IMO good performance mod for little outlay, my type r is a toy though so never spent much time in traffic, but as stated above you need to make sure both work well together, some clutch flywheel combo's don't work well together.

Thanks guys, I'm convinced to stick with 10kg - it's not mapped with the new clutch/flywheel, nor is a lightened flywheel going to sit well with the pinkbox, and if I'm keeping it above 2.5krpm I have a feeling the gearing's going to die from jittering and the fuel consumption's going to jump up.

I'll stick to hovis and bovril and make do with unleashing the thunder in the boring old standard explosion of wonderment.

Ta! :)

How very poetic! Sensible thing to do - Errr...I think!

JohnD

I had an ACT Streetlite flywheel on a previous car, chosen because it wasnt too light, there was a very noticable improvement in the midrange, the car accelerated quite a bit faster.

I did stall it a few times in the first few days but got used to it quite quickly.

Only downside was an increase in noise, not too much, but decelerating at low rpms caused a chugging type noise, not something that will drive you mad though, and definately not noticable if you have the radio on.

Another noise was when the engine was really hot, there was a slight clatter, that disappeared as soon as you put the clutch in. I did have a ACT clutch fitted at the same time though.

I had no judder at all.

For me it was worth doing, and I will be going for the same combo as soon as the clutch on my present car starts to slip.

Unless you use the car on track, the cost of a lightened flywheel is wasted.
The lower moment of inertia will allow the engine to gain revs quicker, but hardly a major factor on a road car.

IMHO

dunx

P.S. I have a Exedy Hyper single with it's lightened flywheel and it's just easier to stall.....

I run a RCM light weigh flywheel with a AP clutch and all works fine with no judder or stall's.

For the cost of the flywheel while the gearbox is off its a worthwhile upgrade.

I had an Exedy Pink clutch fitted to my 5spd along with a 6Kg lightened OE flywheel off the top of my head and it was fecking shocking.

Stunk to high hell in traffic, rattled the car half to death when moving off every time and I can't remember what else but I loathed it.

Lasted less than a week before I went back to a normal flywheel and I will have to try one in another car before I am every convinced to gamble it again!

I have a 6kg and helix clutch and I think it is a worthwhile mod,it does rev freer and had no problems on my 5 speed and now in a 6 speed. It was easier to stall at first and it does not like low rev's in a high gear but you can still potter around in 4th or 5th. Plus I think my old one weight over 13kg, all the little thing add up to make a fast car :).

First off, I'm not an expert on this subject but I do have some common sense and a basic knowledge of physics.

Whilst I can understand that an engine will rev more freely with a lightweight flywheel when it is not engaged to the rest of the car I can't believe that, on a road car, you will notice a sensible difference when you have around 1.5 Tn to dilute the acceleration effect of 4 or 5 Kg of lightening.

Of course, if your aim is to sit at traffic lights blipping the throttle....:norty:

Just to provide a conclusion, I went for lightweight in the end - here's what it was like >>> https://www.scoobynet.com/drivetrain...-findings.html