# Flywheel...needed?



## Ace_bridger (Nov 22, 2011)

I have a Mk2 Golf Ev which still has the original flywheel.

My questions is: Can I do away with the flywheel?

It's primary job is to add some rotary inertia to help smooth the pulsing power delivery of a ICE and secondary job to mate with the starter motor...neither of which are required on an EV.

Does the flywheel play a part in linking the drive from the motor to the gearbox? If it does then removing uneccessary mass from it would help the EV performance?

It must take a lot of power to spin the flywheel detracting from the car's acceleration. OK, you recover most of this energy but I'd rather not do it.

Thoughts welcomed.

Cheers,

Adam


----------



## skooler (Mar 26, 2011)

Hi Adam,

It also has a third job in giving the clutch something to push against - so it is needed if you using a clutch.

Depends if you want a clutch or not?

I lightened mine to about a third its original weight by running it on a lathe, removing the ring gear etc.

In hindsite I'd of replaced it with an aluminium one and lathed that down instead! 

There are a few pictures in my build thread if that helps?

As you say, its not needed to smooth out an engine output adding rotary enertia etc.

Cheers,

Mike


----------



## Woodsmith (Jun 5, 2008)

If you are keeping a clutch then the flywheel becomes a part of that as one of the friction surfaces.

If you are doing without the clutch then there is no need for the flywheel and you just need a splined coupler, made from the old clutch plate centre and a taperlock onto the motor shaft.


----------



## TEV (Nov 25, 2011)

If you keep the clutch system you need it, if you do a clutchless connection you don't need it.


----------



## Ace_bridger (Nov 22, 2011)

Thanks everyone. All clutch components are in the car and are working as far as I know but I do not have the cable connected as yet as I want to run clutchless if at all possible. Mainly because the cable runs straight through where one of batteries sits which is a pain.

So really, once I'm street legal and have had a clutch free testing session I can remove all of that weight and unecessary rotary weight to maximise my chances of beating Skooler's RX-8 at Santa Pod next year!!


----------



## Woodsmith (Jun 5, 2008)

Ace_bridger said:


> So really, once I'm street legal and have had a clutch free testing session I can remove all of that weight and unecessary rotary weight to maximise my chances of beating Skooler's RX-8 at Santa Pod next year!!


Yep, that would be the easiest way. Once you are legal you can then get on with the stuff _you_ want to do.


----------



## skooler (Mar 26, 2011)

Ace_bridger said:


> So really, once I'm street legal and have had a clutch free testing session I can remove all of that weight and unecessary rotary weight to maximise my chances of beating Skooler's RX-8 at Santa Pod next year!!


You've got no chance!

In all seriousness though.... you probably about 2/3rds my cars weight with roughly the same power.


----------



## Woodsmith (Jun 5, 2008)

I wonder what my tractor's time would be at Santa Pod?


----------



## Ace_bridger (Nov 22, 2011)

...sounding like a worried man there Mr Skooler!!!  Wait 'til I get my lithium up-grade...in 20 years!!!



skooler said:


> You've got no chance!
> 
> In all seriousness though.... you probably about 2/3rds my cars weight with roughly the same power.


----------



## Ace_bridger (Nov 22, 2011)

Woodsmith said:


> Yep, that would be the easiest way. Once you are legal you can then get on with the stuff _you_ want to do.


On my road test I had some mechanical noise, like something was rubbing on each motor revolution. I'm in three minds whether to just leave it and get legal and deal with it after, strip the car apart and remedy before MOT or strip car apart, remedy and remove the clutch and flywheel.


I've bought an Impreza engined T3 VW camper for my wife which needs some Isofix bars fitting for the nippers so I think I'll do that this weekend and try to remedy the mechanical noise on the Golf. My wife is taking the kids away to the outlaws so I have a big chunk of time to get stuff done!


----------



## EVfun (Mar 14, 2010)

Ace_bridger said:


> So really, once I'm street legal and have had a clutch free testing session I can remove all of that weight and unecessary rotary weight to maximise my chances of beating Skooler's RX-8 at Santa Pod next year!!


Shifting clutchless with the flywheel and clutch installed will be quite a bit slower than shifting clutchless with a small diameter and light weight motor shaft coupler. Either way, you don't generally go clutchless to win races (unless you have so much power you ditch the tranny too.)


----------



## Caps18 (Jun 8, 2008)

http://waynesev.com/ev/motor2trans.html

I am interested in knowing what was done here... Did he remove all of the outside metal on these and still use the clutch and shifter normally? It would save the weight, and save the $350 aluminum flywheel part.


----------



## Woodsmith (Jun 5, 2008)

Caps18 said:


> http://waynesev.com/ev/motor2trans.html
> 
> I am interested in knowing what was done here... Did he remove all of the outside metal on these and still use the clutch and shifter normally? It would save the weight, and save the $350 aluminum flywheel part.


The flywheel is already bolted to a coupler that fits it to the motor shaft and it may have originally been used with a working clutch.

Looks like he cut the flywheel down and machined it down to only what was needed to bolt it to the clutch centre he removed from the friction material.

There would be no working clutch in this case.


----------

