Boxter S 6 spd gearbox
- Thread starter molleur
- Start date
According to this site Mosler MT900 S - Supercars.net the Mosler MT900 uses a Modified Getrag G50 6-Speed. I don’t think that’s the same trans in the Boxter S
Haven't tried it but.........
It's very much in my mind for a sub-400nm application.
I'm not too comfortable taking it much higher than that, but there's more than one chassis/engine combination that would suit it very nicely....
It's very much in my mind for a sub-400nm application.
I'm not too comfortable taking it much higher than that, but there's more than one chassis/engine combination that would suit it very nicely....
My thoughts are that in a few years time a lot more people will be using these than right now.
With the number of Boxsters and Caymans coming off the production lines its very difficult to imagine that they're not going inevitably be used a lot.
Whether with mods they can surplant the G50 is questionable but I struggle to see why you'd go for a UN1 these days with availability / price there is on these Porsche units.
They have as far as I can tell the same bolt patern etc as the G86 (5 speed) which is the unit I have, currently finding off an the self adaptor kit for my Lex V8 to G86 install has been impossible so its getting done in one off mode. I'm sure at some point though the market will catch up and kits will become available.
With the number of Boxsters and Caymans coming off the production lines its very difficult to imagine that they're not going inevitably be used a lot.
Whether with mods they can surplant the G50 is questionable but I struggle to see why you'd go for a UN1 these days with availability / price there is on these Porsche units.
They have as far as I can tell the same bolt patern etc as the G86 (5 speed) which is the unit I have, currently finding off an the self adaptor kit for my Lex V8 to G86 install has been impossible so its getting done in one off mode. I'm sure at some point though the market will catch up and kits will become available.
Doug, agreed, that looks like an appealing transaxle for all sorts of mid-engine applications, and, I bet you're right in that such use will become more common. Question for you - where did you source the adapter kit you have for the G86? Kennedy or ??
Thanks.
Thanks.
The adaption "kit" I'm using came from my own over active imagination.
FlatChat has the drawings to do the adaptor plate and I'll be sending him the flywheel drawings once I'm covinced I've got that right too.
So he'll be the guy to talk to on that front. Given the bath the Aussie $ just taken they should look cheap from a USA perspective.
FlatChat has the drawings to do the adaptor plate and I'll be sending him the flywheel drawings once I'm covinced I've got that right too.
So he'll be the guy to talk to on that front. Given the bath the Aussie $ just taken they should look cheap from a USA perspective.
For the catalogue hounds - the G86 is the 5 speed, as mentioned, while the 6 speed, from the Boxter S, is the G96.
I happened to see a Boxter S on the back of a truck a few weeks ago - unfortunately it had taken a massive centre punch in the rear:stunned: so I was no longer interested...:sad:
I happened to see a Boxter S on the back of a truck a few weeks ago - unfortunately it had taken a massive centre punch in the rear:stunned: so I was no longer interested...:sad:
Isn't the Boxster S box a varient of the 01X used in Audi/Vw/Seat/Skoda cars?
I believe that both th G86 and G96 have Audi equivalents, but I haven't been able to find a reference to post. Anybody have one?
Seems I had my wires crossed about the part numbers & installations too. See here;
http://www.gt40s.com/forum/gt40-tech-powertrain-transaxles/22599-porsche-g50-g96.html
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G86 is a closer variant to the common audi boxes you guys use. G96 six Speed is a MERWD rendition of the 996 gearboxes. Bigger gear widths, LSD options, stronger casing. However both can be fitted. Boxster guys have been swapping in the S box in place of the five speed on the older cars with nothing more than clutch/axle/linkage swaps. G96 bell pattern is different(few additional fastening points, but still bolts using common bolt locations over 85% of the pattern. Similar to bolting Sti Suby six speed into the older five speed cars(IE 2.5RS).......six speed has 3 more bolt locations that are used on the newer engine cases, but still share 6 common bolt locations and the two drifts/dowels for alignment and securing..
Of the two, get the S box. In the Porsche community the five speed is proven for a good 300-350ftlbs before things start flexing. S box/cayman box is good for 450-500ftlbs in a ~2200lb vehicle with ease. Many modded Caymans and Boxster S's coming close to pushing that power for extended durations, and they've got some fat on top of our weights here. Over that and you need to look into metal treatments to the gearset and main/pinion shafts.
Worked with Ryan @ GBOX a few months back to get a dummy G86 case for mockup here(got the cases), but soon ditched that plan of attack in favor of a locked out AWD Suby 6 speed to take the punishment once I found G86 failures above 300ftlbs were quite common(gear tooth breakage). Suby 6 good for 500wheel with a front LSD upgrade, 7-800 if upgradced to PPG gearset(dog)
-Adam Hennessy
R247 Motorsports
Of the two, get the S box. In the Porsche community the five speed is proven for a good 300-350ftlbs before things start flexing. S box/cayman box is good for 450-500ftlbs in a ~2200lb vehicle with ease. Many modded Caymans and Boxster S's coming close to pushing that power for extended durations, and they've got some fat on top of our weights here. Over that and you need to look into metal treatments to the gearset and main/pinion shafts.
Worked with Ryan @ GBOX a few months back to get a dummy G86 case for mockup here(got the cases), but soon ditched that plan of attack in favor of a locked out AWD Suby 6 speed to take the punishment once I found G86 failures above 300ftlbs were quite common(gear tooth breakage). Suby 6 good for 500wheel with a front LSD upgrade, 7-800 if upgradced to PPG gearset(dog)
-Adam Hennessy
R247 Motorsports
Wow, the G96 box sounds like a solid piece of engineering for handling decent torque. Does anyone know of availability of an adapter plate that might work for SBF (Flatchat??)? This just might be a better box (sub 500ft/lbs tq) with greater parts availability than the ZF.
Correctly so. G96 doesn't quite have the "legroom" in the first few gears like the turbo variants of the G50 and 996 turbo boxes(tt, GT2, etc).
There is another issue with the boxster and boxster S gearbox to take not of. These are indeed variants of the G96 street gearbox, and as such suffer from the same weakness in the dogrings on first and second gear. If someone decides to go this direct, be very careful of 1st and 2nd gear shifts up and down.
I have not heard of geartooth breakage in applications over 300, but I know for sure that the dogs are very shallow and can be easily damaged if you are not careful.
We have a couple of things that we can do to help with the issue, and I have a 6 speed gearbox from a boxster S here if someone is in need of one.
Be careful all in getting a used gearbox from one of these. I can pretty much guarantee that the first and second gears will be damaged to some extent. These are not outragious to fix but take that into account with you purchase price.
Hope that this helps.
Erik Johnson
Carquip Sales
(303) 443-1343 ext 2 work
(720) 980-9407 cell
I have not heard of geartooth breakage in applications over 300, but I know for sure that the dogs are very shallow and can be easily damaged if you are not careful.
We have a couple of things that we can do to help with the issue, and I have a 6 speed gearbox from a boxster S here if someone is in need of one.
Be careful all in getting a used gearbox from one of these. I can pretty much guarantee that the first and second gears will be damaged to some extent. These are not outragious to fix but take that into account with you purchase price.
Hope that this helps.
Erik Johnson
Carquip Sales
(303) 443-1343 ext 2 work
(720) 980-9407 cell
Oh one more thing, the Mosler cars do not use this gearbox, I know as our company built the gearboxes for the Mosler cars for a bit of time. They used GT3 gearboxes that we modified quite a bit.
FYI Erik
FYI Erik
Erik,
How does this box compare to the Audi 01X?
How does this box compare to the Audi 01X?
I am running 385 hp (320 torque) in my Boxster (911 997 X-51 Engine) with no problems. I upgraded the clutch to a Sachs Sport. I track the car often with no problems.
Guys on Caymanclub also turbocharge the 3.4L with an upgraded clutch - no failures so far. ( I think that they are making in the high 400's for hp).
Mike
Guys on Caymanclub also turbocharge the 3.4L with an upgraded clutch - no failures so far. ( I think that they are making in the high 400's for hp).
Mike
Erik, your are correct and I am mistaken. I meant to say dog teeth and not gear teeth. they are the culprit in failures in higher hp setups.
I personally have not toyed with cryo treatments, nor shot/laser peening, on any G86 variants as of yet. I'd be interested in seeing what may become of the problems if such treatments are applied to the G86 internals. I've utilized these processes(not so much the laser peening though) in many other avenues with good success. Might prove a worthy option here to stave off gearbox damage in the upper limits of the torque holding capabilities of the internals
