GT3 gearbox into 964/993?
05-18-2017, 02:09 PM
#17
But the GT3 'box has the correct hole pattern so no adaptor plate needed right?
Wouldn't have thought the 996TT would be close. Also doesn't the starter motor mount differently so would require a lot of head scratching.
I've kicked the idea of adapting a 996/997 box to mount onto a 964 engine but it's a big task!
Wouldn't have thought the 996TT would be close. Also doesn't the starter motor mount differently so would require a lot of head scratching.
I've kicked the idea of adapting a 996/997 box to mount onto a 964 engine but it's a big task!
05-18-2017, 06:55 PM
#18
Race Car
i looked at it at length today ...
to my inexperienced/hopeful eyes and a straight edge:
1. 997/3 box is narrower, shorter in general by 3-5cm so those are easier problems to solve than if it were bigger
2. There is enough room where the shifter cables attach on the RHS of the box for the shifter despite the 964 rear suspension point (much easier in 993 )etc.. - I hope I'm right about that as that's key
3. The front gbox mount on the 7 box is different to the 64 as it is 45 deg angle but an adapter 'wedge' can't be hard to make to take up the space ...
4. didn't look at the drive shafts but imagine they'll need to be changed too i.e. not insig additional cost .. true?
5. the 7 trans oil cooler can be 'remoted' if there isn't space and that's nice to have even if the car only delivers 320hp
6. you need the 996/7 cup car cables (ideally) and the gt3 shifter (needs to be cut down to fit the tunnel; nice place to make a CAE type base for the shifter)
7. the ratios for the 7 box shd be even shorter on the 964 with its smaller circumfrence tire I think so even a non cup 7 ratio box should be preferable espec. if it's running the 4.0 R&Pinion instead of the G50/03 3.44
8. didn't look at the starter and the slave cylinder mounting ... i guess the later is non-issue beyond changing pipe length/finding a mount ... not sure re the starter
any comments or questions or thoughts? thanks!
and yes a 993 RS box with Guard Transmission steel synchros for $6k would be gladly accepted
Matt
to my inexperienced/hopeful eyes and a straight edge:
1. 997/3 box is narrower, shorter in general by 3-5cm so those are easier problems to solve than if it were bigger
2. There is enough room where the shifter cables attach on the RHS of the box for the shifter despite the 964 rear suspension point (much easier in 993 )etc.. - I hope I'm right about that as that's key
3. The front gbox mount on the 7 box is different to the 64 as it is 45 deg angle but an adapter 'wedge' can't be hard to make to take up the space ...
4. didn't look at the drive shafts but imagine they'll need to be changed too i.e. not insig additional cost .. true?
5. the 7 trans oil cooler can be 'remoted' if there isn't space and that's nice to have even if the car only delivers 320hp
6. you need the 996/7 cup car cables (ideally) and the gt3 shifter (needs to be cut down to fit the tunnel; nice place to make a CAE type base for the shifter)
7. the ratios for the 7 box shd be even shorter on the 964 with its smaller circumfrence tire I think so even a non cup 7 ratio box should be preferable espec. if it's running the 4.0 R&Pinion instead of the G50/03 3.44
8. didn't look at the starter and the slave cylinder mounting ... i guess the later is non-issue beyond changing pipe length/finding a mount ... not sure re the starter
any comments or questions or thoughts? thanks!
and yes a 993 RS box with Guard Transmission steel synchros for $6k would be gladly accepted
Matt
05-18-2017, 11:43 PM
#19
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I could've sworn 9M or someone else had done this successfully with a CAE shifter since this thread was originally started in '08. I'll have to look for that thread. Anyway, I'm in the market for a short gear 6mt upgrade so I will be following this thread.
05-22-2017, 02:08 AM
#20
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apologies for the ancient thread bump ... Colin or anyone else - done this into a 3.8 964 yet?
I just measured the two boxes - from engine edge of bellhousing to front edge of box (where the rod is on the 964) and surprisingly the GT3 box seems to be 30mm shorter ie 964 gbox = 790mm and GT3 box 760mm.
I just measured the two boxes - from engine edge of bellhousing to front edge of box (where the rod is on the 964) and surprisingly the GT3 box seems to be 30mm shorter ie 964 gbox = 790mm and GT3 box 760mm.
https://rennlist.com/forums/964-foru...latform-6.html
https://rennlist.com/forums/964-foru...atform-15.html
https://rennlist.com/forums/964-foru...atform-34.html
https://rennlist.com/forums/964-foru...atform-37.html
Thanks,
Dave
05-22-2017, 09:31 AM
#21
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Thanks Dave, you beat me to it.
Yes, it can be done. No it's not easy:
Relocate handbrake tubes, graft in GT3 gear lever support, manufacture custom cables, re-angle selector lever on gearbox, make new brackets, etc.....
Yes, it can be done. No it's not easy:
Relocate handbrake tubes, graft in GT3 gear lever support, manufacture custom cables, re-angle selector lever on gearbox, make new brackets, etc.....
05-22-2017, 02:37 PM
#22
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05-22-2017, 02:56 PM
#23
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The transmission is mentioned. See post #223 in the first link.
https://rennlist.com/forums/964-foru...orm-6.html#223
https://rennlist.com/forums/964-foru...orm-6.html#223
05-22-2017, 02:57 PM
#24
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05-22-2017, 03:38 PM
#25
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^^ sweet! AIRCON doing enough?
found this answer using an alt search approach - thanks!
Thanks Rob - for some reason when I click the link it takes me to post 103 .. must be some setting I've got wrong - will find that manually. (edit: using 'search thread: gearbox' works perfectly)
where I found 223 ... https://rennlist.com/forums/964-foru...atform-12.html
found this answer using an alt search approach - thanks!
The GT3 gearbox, gearchange and ABS are a hit. The gear ratios from the GT3RS are pretty much perfect even for the temporary 7000rpm limit 964RS engine and the Cup cable equipped gearchange is certainly a benefit to the 993RS rod change as there is no movement of the gate when changing gear under high lateral G. Shame that the same could not have been said about our 964 gearknob which flexed under load, so that will definitely have to be reviewed. My subjective view of the GT3 ABS system is that it has a faster response than the 933RS system. It is almost imperceptible in use, you cannot feel anything through the brake pedal even when hard trail braking up to the apex of a chicane, so that's also allayed any concern over the front suspension scrub radius change from the radically wider track (scrub radius is the offset of the pivot centreline of the front strut with the contact centre of the tyre).
where I found 223 ... https://rennlist.com/forums/964-foru...atform-12.html
Last edited by HiWind; 05-22-2017 at 04:06 PM.
05-22-2017, 10:40 PM
#26
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So, since we're on the subject... how much bigger are those new fangled 7 speed manuals? A short 1-6 plus a highway gear would be a dream. I'm guessing its an entirely impractical application.
