Lightening the Flywheel....

[DDtB]

hmmmm.... lots to think about ... (i'll try and read Robin's maths again when i don't have a bottle of chianti inside me! )

Basically gearbox is going to be off the car in a couple of weeks and I'm just looking at what else is worth doing at the same time... like flywheel, manifolds, clutch etc. etc. etc.


*hic*

Dave.

[campbell]

Always nice to have the maffs laid out for us. Thanks Doctor Robin!!!

I had thought about this a while ago, but since not yet had reason to have the 'box out, never went anywhere with it.

I also thought about a CR box, but for same reason, never progressed. Plus I like listening to Radio Scotland on the m-way and this is just do-able with about 2.9k rpm dialled in (=70mph in case anyone had any doubts...). CR box makes it more like 3.4k rpm which is a bit resonant. Albeit the car will doubtless feel more eager.

Anyway, I digress. As usual.

Leave it alone Dave

[hiscot]

on an elise there is no disadvantage you should get slightly quicker acceleration in first less advantage in 2nd ect ect however the engine will spin up faster and does make for crisper gear changes but dont forget we are only talking approx 2kg but at least its right at the outer edge of the flywheel and that has the most effect ( its not just the overall rotational mass loss but where from )
to make a huge difference you would require a smaller diameter clutch , the std cover is very heavy
Steve B has a converted race 7.25 clutch and hellex alloy flywheel that weighs 6kg in total this according to himself gives a acceleration advantage in first of minus 60kg mass , a good advantage for a sprint / hill car
all the vhpd ( exige , 340 and s1 190 ) engines had the ptp flywheel , there was reports of poor fit and balance but again how balanced is a std clutch , i have not found any problems with my low 7200 rpm limit
you will not have any stalling problems or other downsides with the ptp flywheel and for the cost of a s/h one ( see dan ) i would fit it with a new clutch and bearing

[robin]

If you do fit a lightweight one it might make sense to get it rebalanced with your existing clutch cover.

Cheers,
Robin

[Dominic]

I have had a couple of cars with lighweight flywheels. They do rev more freely, but are more easily stalled. You do however get use to it, and quickly the stalling is not an issue. I always found it amusing in my Clio whenever anyone else had a shot of it; they'd always take 3 attempts to get off the mark without stalling. Go for it, it will give the car a more racy character

[philthy]

I felt massive difference with both evos I put light flywheels on, does make it easier to stall, esp with paddle clutches

[Corranga]

I always found it amusing in my Clio whenever anyone else had a shot of it; they'd always take 3 attempts to get off the mark without stalling. Go for it, it will give the car a more racy character

Poll skewed towards good idea by me solely because I like this and this

Chris

[thinfourth]

The downside

If it ain't done well and carefully by someone who knows what they are up to you have just made a very nice bomb


There is a sh*t of energy in a flywheel and if it goes pop its leaving the bellhousing and ain't stopping until it hits something very hard or runs out of energy