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Driveshafts for RWD transaxle

Matthew Spielberg
 

A friend is working an a dyno for low power engines and needs an driveshaft to go between, say, a Sports 800 engine and the newly acquired dyno. Needs to be balanced to a gnats posterior.

Any suggestions? Thinking Porsche 924 or early Pontiac Tempest with rear transaxle.

Or a front wheel drive CV shaft with a slip joint.

Any insights?

Sent from my IBM Selectric

adrian cockcroft
 

On Sun, Mar 22, 2020 at 12:49 PM Matthew Spielberg <mspielberg@...> wrote:
A friend is working an a dyno for low power engines and needs an driveshaft to go between, say, a Sports 800 engine and the newly acquired dyno. Needs to be balanced to a gnats posterior.

Any suggestions? Thinking Porsche 924 or early Pontiac Tempest with rear transaxle.

Or a front wheel drive CV shaft with a slip joint.

Any insights?

Sent from my IBM Selectric



Matthew Spielberg
 

Needs to be able to handle up to 100HP at some 6000 RPM.  Should I call my Citroen dealer to check on availability?

On 3/22/2020 1:39 PM, adrian cockcroft wrote:
I think you should use a Citroen SM auxiliary drive shaft, to be suitably arcane about it. 

Here’s a picture 

Cheers Adrian 

On Sun, Mar 22, 2020 at 12:49 PM Matthew Spielberg <mspielberg@...> wrote:
A friend is working an a dyno for low power engines and needs an driveshaft to go between, say, a Sports 800 engine and the newly acquired dyno. Needs to be balanced to a gnats posterior.

Any suggestions? Thinking Porsche 924 or early Pontiac Tempest with rear transaxle.

Or a front wheel drive CV shaft with a slip joint.

Any insights?

Sent from my IBM Selectric



-- 
Matthew M Spielberg
21855 Redwood Road
Castro Valley, CA 94546
(510) 886-5751
(209) 586-0250

Ken Nelson
 

Rear wheel driveshafts turn much faster than FWD ones, ad they're going into the reduction gear of the differential.  So - I'm not sure I'd trust any FWD shaft vs a RWD shaft and Ujoints.  

Ken

On Sun, Mar 22, 2020 at 12:49 PM Matthew Spielberg <mspielberg@...> wrote:
A friend is working an a dyno for low power engines and needs an driveshaft to go between, say, a Sports 800 engine and the newly acquired dyno. Needs to be balanced to a gnats posterior.

Any suggestions? Thinking Porsche 924 or early Pontiac Tempest with rear transaxle.

Or a front wheel drive CV shaft with a slip joint.

Any insights?

Sent from my IBM Selectric



adrian cockcroft
 

The SM aux runs at high revs but doesn’t transmit much power. 

Maybe look for a driveshaft from an old car with a rear gearbox like a Porsche 924-944 since they run the driveshaft at engine speed. 

Adrian


On Sun, Mar 22, 2020 at 5:48 PM Ken Nelson <citbuff@...> wrote:
Rear wheel driveshafts turn much faster than FWD ones, ad they're going into the reduction gear of the differential.  So - I'm not sure I'd trust any FWD shaft vs a RWD shaft and Ujoints.  

Ken

On Sun, Mar 22, 2020 at 12:49 PM Matthew Spielberg <mspielberg@...> wrote:
A friend is working an a dyno for low power engines and needs an driveshaft to go between, say, a Sports 800 engine and the newly acquired dyno. Needs to be balanced to a gnats posterior.

Any suggestions? Thinking Porsche 924 or early Pontiac Tempest with rear transaxle.

Or a front wheel drive CV shaft with a slip joint.

Any insights?

Sent from my IBM Selectric



Fred Cisin
 

How about the "SADS" from a Previa?
It takes engine RPM to drive alternator, AC, water pump, etc.
The couplings go bad, but some people are using BMW driveshaft couplers.

On Sun, 22 Mar 2020, adrian cockcroft wrote:

The SM aux runs at high revs but doesn’t transmit much power.

Maybe look for a driveshaft from an old car with a rear gearbox like a
Porsche 924-944 since they run the driveshaft at engine speed.

Adrian


On Sun, Mar 22, 2020 at 5:48 PM Ken Nelson <citbuff@...> wrote:

Rear wheel driveshafts turn much faster than FWD ones, ad they're going
into the reduction gear of the differential. So - I'm not sure I'd trust
any FWD shaft vs a RWD shaft and Ujoints.

Ken

On Sun, Mar 22, 2020 at 12:49 PM Matthew Spielberg <
mspielberg@...> wrote:

A friend is working an a dyno for low power engines and needs an
driveshaft to go between, say, a Sports 800 engine and the newly acquired
dyno. Needs to be balanced to a gnats posterior.

Any suggestions? Thinking Porsche 924 or early Pontiac Tempest with rear
transaxle.

Or a front wheel drive CV shaft with a slip joint.

Any insights?

Sent from my IBM Selectric

Christopher Freitas
 

Lots of cars are using CV joints on rear wheel drive driveshafts - including lots of high HP muscle cars.   The joints are basically the same as used on half axles but the boots are different and the angles they operate are less.   

Driveshafts spin faster than engine speed when the tranny is in overdrive. 

I've got a set of Porsche 944 lobro CVs installed on a driveshaft for the last 2 years without any issues.  It spins up to 4500 rpm in that application.  Engine is about 90HP.

On Sun, Mar 22, 2020, 6:49 PM Fred Cisin <cisin@...> wrote:
How about the "SADS" from a Previa?
It takes engine RPM to drive alternator, AC, water pump, etc.
The couplings go bad, but some people are using BMW driveshaft couplers.


On Sun, 22 Mar 2020, adrian cockcroft wrote:

> The SM aux runs at high revs but doesn’t transmit much power.
>
> Maybe look for a driveshaft from an old car with a rear gearbox like a
> Porsche 924-944 since they run the driveshaft at engine speed.
>
> Adrian
>
>
> On Sun, Mar 22, 2020 at 5:48 PM Ken Nelson <citbuff@...> wrote:
>
>> Rear wheel driveshafts turn much faster than FWD ones, ad they're going
>> into the reduction gear of the differential.  So - I'm not sure I'd trust
>> any FWD shaft vs a RWD shaft and Ujoints.
>>
>> Ken
>>
>> On Sun, Mar 22, 2020 at 12:49 PM Matthew Spielberg <
>> mspielberg@...> wrote:
>>
>>> A friend is working an a dyno for low power engines and needs an
>>> driveshaft to go between, say, a Sports 800 engine and the newly acquired
>>> dyno. Needs to be balanced to a gnats posterior.
>>>
>>> Any suggestions? Thinking Porsche 924 or early Pontiac Tempest with rear
>>> transaxle.
>>>
>>> Or a front wheel drive CV shaft with a slip joint.
>>>
>>> Any insights?
>>>
>>> Sent from my IBM Selectric



Christopher Freitas
 

Should have mentioned I am using a VW thing axle as the shaft - it was the right length for my needs.

CVs allow for some in/out length movement also - so no slip joint is needed as long as you have things reasonably aligned.