# Attatch Motor straight to Driveshaft ? Porsche 944



## Woodsmith (Jun 5, 2008)

It should be fine fitting the motor straight to the shaft in the torque tube.
The clutch is with the engine isn't it? It would mean that you will be running without the clutch in that case. Not a major issue as many people run clutchless.


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## JTWeston (Jan 6, 2010)

Woodsmith said:


> It should be fine fitting the motor straight to the shaft in the torque tube.
> The clutch is with the engine isn't it? It would mean that you will be running without the clutch in that case. Not a major issue as many people run clutchless.
> 
> 
> ...


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## Woodsmith (Jun 5, 2008)

I would assume that it would be straight forward but it depends on how the shaft is located in the torque tube and where you want to couple the motor. If you are replacing the ICE with the motor then you are only looking to make an adaptor plate to mount the motor on the bell housing and then the motor can couple using the clutch centre splines.

If you are looking to mount the motor to the transaxle, removing most of the torque tube then that would be much more fiddly to sort out due to space and mountings to the tube and the drive shaft.

My preference would be make the drive end of the motor match the output of the ICE using an adaptor plate and then having the option to keep the clutch. I don't know how well the box will take to clutchless shifting.
With the right motor and battery voltage you may only need to use 2nd and 3rd but that can be sorted out later on.

I have looked at the Porker's transaxle for my MR2 so that I can mount the motor in the large tunnel area where the fuel tank used to be but it was too expensive.


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## electromet (Oct 20, 2009)

JT,

I think your best bet is to use the existing bellhousing as it will give a mounting surface perpendicular to the driveshaft centerline. Since the 944 driveshaft is rigid (i.e. no u-joints at either end) it is absolutely imperative that the motor mounting plate be absolutely perpendicular to the driveshaft. I personally would not want to open up the torque tube to shorten the driveshaft, as I see at least four bearings and a damper in there.

As far as the clutch is concerned, I tend to think that a clutch is a good thing on a car with a remotely mounted gear shift assembly. I've not driven a 924/944, but I have driven 911's, 914's, classic VW's, and Corvairs. The shifting linkages can be described as sloppy at best with any of these cars. Keeping the clutch intact can't help but take some of the guesswork out of shifting.


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## DavidDymaxion (Dec 1, 2008)

The driveshaft spins at motor speed. That additional rotational inertia is going to make clutchless shifting harder to do. I don't know how much is shared with the 911 tranny, but FWIW mine hates shifting clutchless (sometimes can't shift at all), but is easy with the clutch.


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## JTWeston (Jan 6, 2010)

Thats great, thanks to all for the help. This gives me enough info to move forward. I'll be back soon with more questions I'm sure.


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## JTWeston (Jan 6, 2010)

I have been talking to the boys in the workshop and they are concerned about the pressure on the electric motor if i mount it to the clutch ?? They seem to think like I originally did that it would be easier to attatch straight to the driveshaft.? Any more thoughts team??


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## Woodsmith (Jun 5, 2008)

I don't think the clutch pressure will be an issue. Many people run electric motors with a flywheel and clutch and have had no issues around that.

The clutch isn't used as much anyway and it is only momentary, only used to change from, say, 2nd to 3rd as the only gears you will probably need. It is not as if you would sit at the stop light with your foot on the clutch either as the motor will also be stopped.


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## drbulley (Jul 28, 2010)

I'm also starting a 944 conversion. Would be interested in your progress. I basically just got the engine out and haven't chose a drive system yet, AC vs. DC.


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