mx5cartalk.com

Hello,

Did a quick search and didnt turn up much that was useful. About to change the clutch and gearbox and wanted to get some recommendations regarding Lightweight Flywheel. Looking at these two:

http://www.mx5mania.com.au/product1685.htm
http://www.flyinmiata.com/index.php?deptid=4531&parentid=0&stocknumber=08-26500%20%2010.30

Am I on the right track? Car is used mainly as a daily drive with occasional track use. It is a 98 NB 1.8L.

Cheers!!

Hi SaM,
I have the 10.3 FM flywheel in my car and love it.
Yes it does have a slight noise on back off but nothing to worry about.
I find it revs alot quicker and seems to be better going up hills.
Hope this helps.

John.

One of my favourite mods! I have an NB but I'm running a TODA 1.6 flywheel and clutch to suit. It is only 3.8kg! The 1.6 bits work fine on a 1.8 if you swap them together.

do some research - what benefit is it for a standard road car and if its a good idea why does n't the manufacturer do it? A good start is talk to a clutch fitter or two and ask for some advice without a leading question.

I've got a lightened flywheel on my car, an NB8C, and apart from about 15 mins to get used to it (taking off on steep hills) it is great! Car feels much more lively and responsive.

Mr Morlock wrote:do some research - what benefit is it for a standard road car and if its a good idea why does n't the manufacturer do it? A good start is talk to a clutch fitter or two and ask for some advice without a leading question.

Manufacturers do all sorts of horrible things to flywheels now.........that would be the last thing I took into consideration if looking for a performance upgrade. They are heavy to make things smooth and quiet originally.

Honestly, a lightweight unit is good within reason. My advise, Don't over do it on a road car, it can make them unpleasant. A basic lightweight unit (one better than std) would be ample and make the car more responsive without causing any other issues. If you try and fit the lightest unit possible on a road car it will cause other issues.

Cheers
Woz

Good advise Woz.

Here's a thought, why can't the stock fly be machined/drilled to a lighter spec?

Not worth the trouble?
Safety?
LightWt flys are usually some strong light alloy?

Just something I have always wondered about.

Aussie Stig wrote:Good advise Woz.

Here's a thought, why can't the stock fly be machined/drilled to a lighter spec?

Not worth the trouble?
Safety?
LightWt flys are usually some strong light alloy?

Just something I have always wondered about.

If it's done correctly absolutely no reason at all, in fact my car is fitted with exactly that (athough I now have a moly unit for a later date..... )

The biggest issue with it is that people machine them incorrectly, by over doing it (taking to much off), or machining in the wrong areas (taking strength away from key areas). That is when it becomes a massive safety issue. I have had a flywheel come off a race car, I can assure you it's not pretty.

Great care needs to be taken when carrying out this type of work, but it can be done.

cheers
Woz

yoda7356 wrote:I have the 10.3 FM flywheel in my car and love it. Yes it does have a slight noise on back off but nothing to worry about.

Just out of curiosity, what kind of noise does a lightened flywheel make? Is it like a whining sound?

Smacca wrote:

yoda7356 wrote:I have the 10.3 FM flywheel in my car and love it. Yes it does have a slight noise on back off but nothing to worry about.

Just out of curiosity, what kind of noise does a lightened flywheel make? Is it like a whining sound?

It shouldnt make any noise whatsoever....

Woz

there is a very simple reason why it is not a good plan for a road car and surprised that people do not know- the knowledge has been around for decades. Keep the revs up boys. Lightened flywheels are part of a routine with other mods for racing vehicles which are dríven flat chat. It has absolutely nothing to do with OEMs not getting it right- quite the contrary- they build cars and engines tuned for purpose and Mazda seemed to have got that right with the MX5. PS in the old days it was common practise to machine flywheels to reduce weight.

Mr Morlock wrote:there is a very simple reason why it is not a good plan for a road car and surprised that people do not know- the knowledge has been around for decades. Keep the revs up boys. Lightened flywheels are part of a routine with other mods for racing vehicles which are dríven flat chat. It has absolutely nothing to do with OEMs not getting it right- quite the contrary- they build cars and engines tuned for purpose and Mazda seemed to have got that right with the MX5. PS in the old days it was common practise to machine flywheels to reduce weight.

If the reason is simple please explain?

I don't agree. It has everything to do with OEM being a compromise between smoothness, noise (these days with dual mass units) and performance, alot of things are taken into consideration, and most of it isn't about performance. As with any other area on a motor vehicle.

The std MX5 wheel is very heavy, but as stated earlier it would be the wrong thing to do to put the lightest clutch and flywheel unit you can find in there as drivability would suffer alot. However, a substancial amount of weight can be taken out with very little compromise elsewhere. The cars I have done responded very well to sensible changes.

At the end of the day it's about how you like your car to drive and how responsive you like your engine to be and what you intend to do with it.

Cheers
Woz

i drive my car as a daily and have one of the lightest combos available

if you are worried about a lightweight flywheel in a sports car (insert preferred cliche).

if you want you can come check out my car this weekend.

just pm me if you are interested.

SaM,

I have just done this exact modification on my 99 NB and love it. I Purchased an Exedy combo kit from Goodwin Racing which consisted of a stage 1 heavy duty clutch and exedy lightened flywheel. I did a tonne of research and decide on this kit because it is of good quality and suited for the daily drive. I could have gone for a much lighter flywheel but had heard of issues when it came to heavy traffic. It cost me $714 including freight. I am sure that you could do it cheaper but I actually saved money compared to the kit I was going to purchase in Australia. Brian from Goodwin Racing was great to deal with and my gear arrived in just over a week. My car is definately more responsive and has an extra spring in its step.

Check the price with MX5 Mania (call them up). I found there wasn't as much of a difference as I thought.

I got my clutch and lightened flywheel from Goodwin as well but it wasn't a huge saving.