# Clutch Advice



## grip911 (Dec 14, 2011)

My stage 3+ by spec has a solid disc on a springed center and works pretty good. stage 3 and up should be fine for what you need.


----------



## TheSGC (Nov 15, 2007)

I have a Stage 4 Clutch in my Civic and I find it works great.

http://2001-civic-ev.blogspot.com/2012/08/transmission-removal.html

It's definitely more difficult than the stock clutch, but after a while you get used to it and I only use it for shifting. I don't walk lopsided, but my left leg is definitely stronger than my right one now!


----------



## dtbaker (Jan 5, 2008)

hhhmmmm, I've had no troubles (yet=5000 miles) with stage 1 Exedy in my Miata w/ Warp9/zilla/156v.


----------



## Roy Von Rogers (Mar 21, 2009)

I have been thinking for some time about using a clutch for an electric motor. It seems to me were adapting from an ice type clutch and trying to make it work for a different animal that has a lot more torque.

It seems we need to take whats done in a lock up type torque converter and adapt the same strategy. 

Why couldnt we make a clutch that locks up in to the teeth of the flywheel, right at the end of total clutch release. ??

Roy


----------



## Lordwacky (Jan 28, 2009)

The Torque holding aspects are relatively straight forward and fairly easy to determine.

I'm mostly interested in the drive ability aspects, I'm mostly interested in the sprung vs unstrung question. 

Does anyone have experience with an unsprung disk? How much whiplash can I expect when changing the gears?


----------



## Lordwacky (Jan 28, 2009)

dtbaker said:


> hhhmmmm, I've had no troubles (yet=5000 miles) with stage 1 Exedy in my Miata w/ Warp9/zilla/156v.


I had ~4500 miles on my stage 1 (slightly upgraded from OEM) Exedy. I have essentially the same set up that you do, [email protected] w/ Warp 9. 
But in the Mk1 MR2, So I'm probably heavier.

I would imagine all comes down to how you drive, I drive pretty gently and have only "pushed it" small handful of times. When I pushed it I could feel the clutch slip a little so in retrospect I should have known I was marginal with my setup.

Long story short, I wouldn't be surprised if you'll be doing a clutch R&R in the next 5k miles.


----------



## Lordwacky (Jan 28, 2009)

Roy Von Rogers said:


> I have been thinking for some time about using a clutch for an electric motor. It seems to me were adapting from an ice type clutch and trying to make it work for a different animal that has a lot more torque.
> 
> It seems we need to take whats done in a lock up type torque converter and adapt the same strategy.
> 
> ...


I'm sure we could, in fact I wouldn't be surprised is some out there already has. If you disengaged it while moving you would need a syncro so there wasn't a mashing of teeth, just like a manual transmission.

The problem comes into the practicality of delevopling a hold new setup, when there are already mass produced options out there that are more time and cost affective.


----------



## Roy Von Rogers (Mar 21, 2009)

No the clutch would engage first, then the lock up. the clutch would be the syncro, the lockup would be moving at the same speed as clutch. But I guess you could sense the clutch and flywheel, and if they are the same rpm, lock it electrically.


Roy


----------



## mizlplix (May 1, 2011)

It takes the same torque to move your car with an ICE or electric power.

(sounds like crap?)

You are limited as to the torque required by car weight, road surface and tire traction. None of which are changed by power plant selection and will be limited by the weakest link in the power trane. Usually the tire contact traction.

Most standard clutches that will motivate your car will be fine with electric power unless you change one or more of those items.

Like.....put on a 12" slick. But a 2,800# clutch will still handle most EV motors even then.

Exotic is not always good.

If you want to use a standard clutch set up, have the starter gear removed, the o.d. Turned down as much as possible, have it thinned a bunch to lighten it up. You do not need all of that thermal mass or rotational inertia either. You are starting out with the clutch engaged, it is not slipping to build heat....

You are merely using it to make shifting faster.

Miz


----------



## Roy Von Rogers (Mar 21, 2009)

Torque is not the same torque, unless you quantify when it occurs.


Roy


----------



## elevatorguy (Jul 26, 2007)

Stock clutch, 165 volts, 1000 amps, warp 9 2800# car I think it slipped a bit with full throttle in 3rd from dead stop, otherwise no issues.
I beat on it pretty hard and it holds up


----------



## Lordwacky (Jan 28, 2009)

mizlplix said:


> It takes the same torque to move your car with an ICE or electric power.
> 
> (sounds like crap?)
> 
> ...



You are correct the torque on the drive shaft required to move an electric and ICE car of the same mass and at the same acceleration will be the same. That's a simple applicaiton of newtons second law and I think we all understand that. But what you are forgetting is that torque on the flywheel will not necessarily be the same in an ICE because most people do not use 1st, most will start in 2nd or third, which means that the torque on the fly wheel/pressure plate will be higher because the mechanical advantage of the transmission is less. 

This is also coupled with the difference that the clutch on an ICE is feathered in and the peak torque isn't usualy applied until the car has started rolling making the transition smoother. While in an electric car, max torque occurs @ 0 rpm and the clutch is already fully engaged, but the car is not moving, that puts a lot of stress on the pressure plate/flywheel interface.

If I was starting in first all the time my clutch probably would have lasted longer than it did, but I wasn't. I really don't want to have to use "granny gear" unless I need to travel at slow speeds or I'm starting on a steep hill. because it can be a bit jerky.

So unless your car had a very strong OEM clutch setup to begin with you should consider upgrading


----------



## grip911 (Dec 14, 2011)

very well explained


----------



## electro wrks (Mar 5, 2012)

The problem is that most ICE clutch pressure plates have a flyweight feature built in that increases the pressure on the clutch(and its torque transmitting capacity) as the rpm increases. Here's a description for diaphragm type pressure plates: 

http://www.motoiq.com/MagazineArtic...h-Part-One-The-Pressure-Plate-Get-a-Grip.aspx

This is great for an ICE where the torque starts at near 0 and increases as the RPM increases. Most electric motors have just the opposite torque characteristics and clutch requirements.


----------



## onegreenev (May 18, 2012)

Not sure where you get that from. I have used stock and done just fine but if you have any decent performance and start in 3rd gear then you should have a pretty stout pressure plate setup. If you can get a dual plate pressure plate it will give you lots of holding power with little more than stock pedal pressure. If not get at least a level 3 race setup or even a level 4. If you have hydraulic for your clutch don't worry about it being a stiff clutch. Or just keep your foot off the throttle and be easy with your ride.


----------



## evmetro (Apr 9, 2012)

I found that with much more torque available, my stock clutch would slip in any gear, so I upgraded to a bigger diameter puck style disc and pressure plate. The springs on the pressure plate made the pedal a little stiffer, and the friction pucks don't blend very well. If I was running DC, there would be no problem, but with AC, the regen makes it rough when I let the pedal back out as I am slowing down. I have to be quick.. For DC with no regen, the pucks would not present a problem at all.


----------



## onegreenev (May 18, 2012)

> ......but with AC, the regen makes it rough when I let the pedal back out as I am slowing down. I have to be quick.....


I don't understand the need to feather or disengage the clutch when slowing down? Unless you happen to be downshifting.


----------

