lightened flywheel?

Author
Discussion

Andy70

Original Poster:

1,301 posts

166 months

Tuesday 15th March 2022
quotequote all
would a lightweight flywheel in a NC 2.0L mx5 work well? I'm sort of aware of the pros and cons of these, cons being in some cars/engine sizes the revs can drop too much possibly and stall, more so in bigger engines, is that right? but I've heard they are better in smaller engines, therefore is a 2litre engine small enough? I know they reduce torque a bit too, so would that be noticeable? (bare in mind the car would be tuned somewhat too) tell me if I'm taking crap and I'll shut up ;-) thanks for any help

Evoluzione

10,345 posts

250 months

Tuesday 22nd March 2022
quotequote all
They don't reduce torque, that's crap.
The advantages of a lighter FW are at their greatest in first gear, they are at their least in top gear.
A car fitted with one will be more difficult to set off in and accelerate quicker.
It isn't a lot, let me know if you want to buy one.

pewe

662 posts

226 months

Thursday 31st March 2022
quotequote all
On my s/charged Mk1 1.6 I've ended up with a 5kg flywheel (v c.8kg standard IIRC).
Previously I went for a 4.2kg which is about as light as you can go.
Suffice to say it wasn't in there long as it was very shunty when off throttle on over-run.
Revs would also drop dramatically with load on the alternator i.e headlights, heater blower & windscreen wipers all on.
I'm not saying this will apply to yours but giving it as an example of not going too light.
Suffice to say that pickup in first is pretty good!
HTH. Cheers, Pewe

Andy70

Original Poster:

1,301 posts

166 months

Thursday 31st March 2022
quotequote all
pewe said:
On my s/charged Mk1 1.6 I've ended up with a 5kg flywheel (v c.8kg standard IIRC).
Previously I went for a 4.2kg which is about as light as you can go.
Suffice to say it wasn't in there long as it was very shunty when off throttle on over-run.
Revs would also drop dramatically with load on the alternator i.e headlights, heater blower & windscreen wipers all on.
I'm not saying this will apply to yours but giving it as an example of not going too light.
Suffice to say that pickup in first is pretty good!
HTH. Cheers, Pewe
basically then somewhere in between, i'll try and remember that, thanks


markcoopers

626 posts

200 months

Wednesday 13th April 2022
quotequote all
Hum.....It is not quite as easy as that. As a general rule the points about the engine gaining and loosing revs faster is correct, but where the weight is in the flywheel is important, more so the lighter the wheel. So directly comparing 4.5 vs 5.5Kg wheels when they are different construction is perhaps not the way to make the choice. By rights you should look to the whole clutch and flywheel package for a weight rather than just single components but I digress.

If you have a forced induction/intend to, then a larger surface area and a switch to the 1.8 sized flywheel and clutch may be the solution you need. if staying N/A, then a 1.6 flywheel will be fine.

For me at least I will only purchase a "light flywheel" from someone like TTV as I know the quality I am getting. I once saw the results of a "lightened flywheel" and was amazed the bloke still had his legs. they do a 3.6 or something like that 1.6 wheel that on a ITB'ed car on standalone ECU and good mapping suited the car perfectly.....but it was not a daily driver. If it was a daily I may well leave this mod alone.