993 Gearbox in 964.

[Ian Bloxsom]

Has anyone ever fitted a 993, 6 speed gearbox into a 964 and converted a Carrera 4 into a 2 at the same time.
If so what are the pit falls and timescales involved?
I'm just interested as if my gearbox was to give up the ghost then a 6 speed may be a benifit. To be honest to convert to 2 wheel drive may not be an option in my case as I like the added security of the the 4 wheel drive. Any comments would be welcome.
Thanks.

 

[Dave Wilkinson]

Ian,

I've certainly seen mention on Rennlist of a 993 6-speed gearbox being installed in a 964, but the conversion to RWD might be a bit more complicated. It's the bits you'd have to remove that would likely be a problem because the front drive shaft, differential and half shafts would all have to go. That would almost certainly mean that the front hubs would have to change as well - and then there's the electronics. How would the PDAS system cope with the diff locks??

I'm guessing a 993 C4 gearbox might be an easier switch but it would still leave you a problem with the electronics because the 993 uses a viscous coupling in the centre diff so I'm guessing the traction control will be entirely different.

Whenever the C4 yo C2 conversion comes up the recommendation is always "don't do it". I don't think the 993 gearbox makes it any easier.

Regards

Dave

 

[carreraboy]

Not recommended by 964RS guys who have done it...... how that translates to a C2/4 hmmmm

 

[Steve Brookes]

Personally I think the 5 speed on the 964 is just right. I rarely use 5th as it is (don't really do any cruising in the 964) and find the engine so tractable that I can't see the need for an extra gear lower down to keep it on the boil.

 

[carreraboy]

Maybe get RS Ratios just perfect for Spa .... seriously 993 Box in a 964 only heard negative reports from RS guys speak to Phil Schyns on this forum he should know ....

 

[chrism964]

Adrian Streather says (in his book) it's not worth it without a considerable power increase.

 

[carreraboy]

And torque which the 993 has ....

 

[Alexander_Drobik]

I looked at this in some detail years ago. Can be done but it won't help much. With 305bhp on my car it was still not worth doing - I would have better success with changing the gear ratios - may lose 15-20 mph top speed (as if we can always go over 150 in the uk) but it would close the ratios further down the range.

On track the only time I wished for really close gearing is going through the chicanes: 2 being too high and 3 too low. On other parts it was rare to have the wrong gear - sometimes I would hold the engine at 6800 knowing I could have an extra 300-500 in an ideal world - but I am sure with a six speed I would find other gaps. On track with 993's I never saw an advantage, and unless a 993 was modified, never worried about overtaking them - always did.

So - my take - improve the power, and change the ratios first. The only other advantage for a six speed would be to have an overdrive for the motorway ;-)

 

[nathan 1981 930 G50]

Well, I know of a 3.6 964t that has had a 993 4WD system fitted. It was also articled in 911 & PW.
Anyway, the chap who had it done sold the car, bought a 993tt and has that converted to RWD...

I know this is of no help... []