|
|
|
|
| Author |
|
|
Registered
Join Date: Jun 2001
Location: Mid-Ohio
Posts: 715
|
'73 915 tranny in '84 Carrera?
I have a '73 parts car and an '84 Carrera with at gone tranny.
Is this a plausible Swap? |
||
09-25-2001, 09:14 AM
|
|
|
Registered
Join Date: Dec 1999
Location: TX USA
Posts: 9,804
|
John,
Some will say it is a crazy idea, but it has two distinct advantages related to the gearing change from a 8:31 ring & pinion to 7:31: 1. Acceleration will be better in every gear! 2. Top end will be rpm-limited at approx. 150 mph at redline. 3. Both of the above adds up to more fun, assuming you like to use the gears! You will need to use the speedometer from the '73 as well, which means running a speedo cable through the tunnel since the '73 transaxle does not have provision for the magnetic sender for the electronic speedo. You will have to use the Cv-joints and stub axle from the '73 (different spline count inside the differential carrier) as well, which may involve some machining of the stub axle to fit your aluminum hub carriers. A more expensive and troublesome solution would be to use your '84 915 case and differential carrier, and transfer the contents and nosecone of the '73 transaxle to your aluminum case, giving you a dual speedometer capability ... cable to a '72 thru '74 speedometer or electronic piockup for your later speedo, which would have to be readjusted for the 7:31 ring & pinion. Mixing internal parts also gives you the option of installing the 'shorter' 4th and 5th gears from your '84 915, improving performance even more, at the expense of slightly reduced top end speed! This 'mixed' and more complex option means you have the chance to renew all synchro rings, and any dog teeth, operating sleeves, etc. ... meaning a completely rebuilt transaxle to go back in your car! ------------------ Warren Hall 1973 911S Targa 1992 Dodge Dakota 5.2 4X4 parts hauler |
||
|
09-25-2001, 10:44 AM
|
|
|
Administrator
Join Date: Feb 2000
Location: Los Angeles
Posts: 13,333
|
I have a 73 915 mated to a 93 3.6.
It's a great combination. Approx 150 mph at 6800 redline. I have a pump and an external cooler plumbed in for track use. They say the 915 is reliable up to about 300 hp, although side-stepping the clutch in first is probably not safe. ------------------ Jack Olsen My Rennlist page • My Pelican Gallery page • My Porsche Owners Gallery page |
||
|
09-25-2001, 01:43 PM
|
|
|
Registered
Join Date: Jun 2001
Location: Mid-Ohio
Posts: 715
|
Thank you both.
I'll definitely consider this seriously, Since I have the '73 box just sitting there in good condition. I will keep you updated John |
||
|
09-26-2001, 06:54 AM
|
|
