Flywheel weight reduction?

Iamzod

Iamzod

Iamzod

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I've been looking online via google for answers but i'm getting mixed answers so thought i'd try here.

I will shortly be in a position where the flywheel is out of my car and was considering getting a bit of weight removed to make the engine rev a bit more freely however i'm not sure what to make of the answers I've got as to wether or not it's a good modification to make. I've read everything ranging from it makes a car horrible to drive to it totally transforms the car, read comments like it reduces torque output or releases more BHP.

Does anyone have any feedback from actual experience?
 
Ever wished the engine had less rotational inertia? If not, don't bother, it will make the car trickier to drive in traffic and you will need better rev matching/timing during shifting. If will have no effect on torque, perhaps marginally more bhp will make it to the wheels.
 
I did this years ago, well company rebuilding my engine did.

It definately made the revs drop off quick when you declutched, and felt slightly better on pickup.

Was it worth it, practically impossible to say but its a quick cheap job, just dont go too silly. Think I lost about 30% by weight.

What was interesting was that the flywheel when pulled off wasn't that well balanced so even if you don't have any/much removed its worth asking them to check how good it is.

Its supposed to make the engine feel smoother but the cam profile I had was so extreme with a high intake outake overlap I would never have known.

My advice was from Holday/Coltec racing, trusted them to give honest advice.
 
Clarkey said:
Ever wished the engine had less rotational inertia?
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I've never driven it with that particular engine fitted, in fact the flywheel is from a different variant of the engine fitted to another car, it's a BOA Cosworth V6 but as they were all auto's i'll need to use a Capri/Sierra 2.8 Flywheel.
 
It can give a noticeable improvement in acceleration in the lower gears. It doesn't change the engines torque or bhp, but with less mass in the flywheel to accelerate, more power can be used to accelerate the car.

The amount you can safely remove from a standard cast iron flywheel is unlikely to cause driveability or idle issues. Remove too much metal, or metal from the wrong area and your flywheel will turn into a fragmentation grenade, so ensure you get someone who knows what they are doing to do the machining.

An ultra light steel or aluminium/steel flywheel can cause a rough idle and makes the engine a lot easier to stall, as well as making it pick up very quickly.
 
Ok, kind of goes without saying I would think. An unbalanced fly will knacker up your bottom end bearings and significantly increase the risk of it becoming detached and cutting off your feet too right?
 
Clarkey said:
Ok, kind of goes without saying I would think. An unbalanced fly will knacker up your bottom end bearings and significantly increase the risk of it becoming detached and cutting off your feet too right?
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No idea but you were being the smart arse taking part of a statement out of context and saying its the opposite.

When being balanced I also had to supply the clutch as it was balanced together.
 
Tom_ed1987 said:
I would never fit one to a car you drive on the road normally, only if it were a fun car for ragging about on sunny days.
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That's exactly what it's for, I don't mind a bit of a rough idle.

I'm not wanting to take massive amounts off and if I do get it done it will be by someone that knows what they are doing, I just wanted to know about the effects before I get it done and then not like what I've done.

Does it effect where the power is in the rev range at all?
 
It will just transfer the energy faster thats all.

It will feel "revvier" if its extreme enough, assuming its well balanced it will in theory be smoother.

Being lighter it will as said drop off speed faster as well.

Think of tying a 1kg weight to a long piece of string and spinning it round, then do the same with a 2kg weight. The 2kg will accelerate slower but will also contain more energy and slow slower as well when you stop providing force.

It wont add or subtract torque and BHP it will just transfer those forces more directly.
 
Had one on mine and it made a nice difference. Much more responsive, revved nice and freely. Didn't notice anything bad as a result to be honest.
 
Not on a daily driver no, as said it makes the it trickier to drive and not as smooth.
 
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