6 speed gearbox

[Billybod]

Hello again

I've tried a search but I can't find a topic about fitting a 6 speed gearbox from a 968 into a 944 T. It isn't something I'd planned to consider but wondered if it had been done? Would the gearbox withstand any additional hp and torque of a "chipped" turbo?

I do have a slight obsession with ratios having 35 years ago a TR6 with overdrive but found that od 3rd was almost the same as 4th so I had the gearbox on my 1971 TR6 altered with wide ratio gears so that the overdrive still gave me 6 gears but now with 6 appropriate ratios as 3rd had been "slowed down". There is od on 2nd to actually give 7 gears but it is a bit cruel on the mechanicals under full throttle.

Regards

Bill

 

[Lowtimer]

We've discussed this briefly here before, not sure when. I often think it would be nice to have an extra gear to play with, say a 'lower third' and 'upper third', but objectively it is hard to see that it would be beneficial.

I believe the 968 box would be up to it mechanically, but there is extra weight involved, and with a well set up 944T it's hard to see the benefit. Top gear on a 968 box is numerically higher (lower geared) than top gear on a 944 Turbo so you would need to change the final drive as well to raise the top end. The 968 Turbo S and RS had slightly different gear ratios and a tall final drive to get to their 175-ish top speeds. A tuned 944 Turbo runs into the red line in top not much over 160, but outside Germany that's not much of a practical constraint

If I spent lots of time on the autobahn I would probably consider it, but if you have a well set up 944T with a dual-port wastegate then it goes like stink all the way between 2900 and well over 6000 rpm anyway, so there really aren't any torque holes to fill. If you went for a hot cam profile, you might need more ratios but that just isn't necessary for anything up to about 400 bhp plus.

Couple of threads here on Pelican which might be of interest.

http://forums.pelicanparts.com/porsche-924-944-968-technical-forum/98998-968-6-speed-944-turbo.html
http://forums.pelicanparts.com/porsche-924-944-968-technical-forum/94111-968-turbo-question.html

 

[944 man]

Theres a good deal more to change than the transaxle alone, too.

 

[TTM]

ORIGINAL: Billybod
Would the gearbox withstand any additional hp and torque of a "chipped" turbo?

Completely.
Friend had a more-than-"chipped" 944T and had a lot of fun without any issues on the track with the 6 speed gearbox, though he complained from time to time that the gearing was too short for the motorway.