Lightening the flywheel

[oldroydsr4]

Hi all,

Im in the middle of a turbo conversion and while i have every thing out i want to get as many jobs done as possible.

When finished im aiming for approx 350bhp (fly),

I'm just wondering whether it would be worth having the flywheel lightened,

Whats your opinions, is there as much to gain incomparison to N/A.

cheers

[oakey]

http://www.e30zone.net/modules.php?name ... t=flywheel
have a look thrrough this. im sure someone said somewhere about a lightened flywheel reducing the lag on a F/I motor

[jaistanley]

Well, if the engine can spin up faster it follows more gas will reach the impellor quicker so I guess that's true.

Don't mix up lag and boost threshold though, you'll reach the boost threshold earlier but the absolute lag (typically 0.5 seconds) shouldn't change. It's the time it takes to spin the turbine and pressurise the system (inlet and exhaust manifold), not as people think the time it takes to boost after pressing the throttle at low rpm and the engine having to wind up..

Lightening the flywheel is a good idea though. It'll improve throttle response and will make the engine feel a lot more responsive.

I'd be concerned about lightening a std flywheel very far though for safety reasons. They can let go at high rpm. Either get it lightened only a little by a decent firm,or go find an aluminium 'race' flywheel for the job.

Jai

[oldroydsr4]

Sounds good, what sort of price are the ali flywheels.

Also how much can be removed from the m20 flywheel safely?

Iv just read the other thread on them exploding, it sounds scary.

Id like a responsive car but id prefer my legs.

[jaistanley]

Flywheels exploding is a possibility but it's pretty rare. Decent machine shops will know the limit and if you're not using the car for competition and revving it's nuts off all the time you'd probably be fine.

The aluminium wheels are a touch expensive you see. I was looking for one for my S50 engine but out of my price range at the moment at around £500 ish I think.

Jai

[oldroydsr4]

The car is intended for track days and ring trips etc, but as the limiter is approx 6500rpm it shouldn't be reving its tits off.

iv just checked you can get a ali m20 fly for £300ish, but ligthening approx 60.

should i just leave it?

[jaistanley]

Hmmmm.. I would for now.

£60 isn't bad though.

Put it on your list of upgrades and do it oneday when your clutch gives in.... Thats what I think I'll do. Plus the M20 has a lighter flywheel already than many of the beemer engines.

Where did you see the Ally one for £300?

Jai

[oldroydsr4]

JB racing. i think they cater for the s50 to.

[DanThe]

If you want an M20 flywheel lightening send Templ8e30 a pm, he has machined some meat of mine and ive just got it back, its a very professional finish, better than standard in fact

I would post some pics but my camera is in for repair

[oldroydsr4]

Danthe, how much did he charge.

Pics would be cool.

Whats your opinion on the flywheels failing

cheers

[DanThe]

Send him a pm mate, he had a few tooling problems with mine so he's the man in the know.
TBH im not worried at all about it coming apart.

I should be getting my camera back in the next few days so I will post some pics up soon as