Boxster 2.5 gearbox
- Thread starter Adrian427
- Start date
Scott would know more than most given his work with these types of 'boxes but I would guess that the Boxster transaxle is as strong as the audi 016 - neither of which is particularly strong. The 016 was designed to work with sub 200hp audis from the 80s and the Boxster transaxle was designed to work with 200-225hp porsches in the late 90s. Both of these are somewhat light-duty for a basic SBF with 250 - 300hp. However, there are lots of guys here using 016s fairly reliably with mild SBFs although I expect most are not doing a lot of drop clutch burn outs...
I believe that in Europe, the 012 (Boxster) transaxles are (or were) used behind the Audi A8 V8 motor. That of course is not an endorsement of it's strength, but apparently it is adequate for the task. It would be nice to get some feedback from someone that uses one for their V8 application and perhaps we just might get some, as there's interest looming in the Chevy LS1/Boxster (5 speed) engine swap.
Andy
Andy
Nope all V8 manual transmission were either a beefed up 016 or 01E. The 012 was used in the V6 and 4 cylinder applications.
Don't get me wrong the 012 is a good transmission but it will not survive behind an LS1. The gear widths are too small and the mainshaft and output shaft only have two bearings supporing them, versus 3 for the 01E/01X.
I see all this about what will and what will not work. I think it comes down to the driving habits and use of the engine/trans combo. Putting a 400hp V8 on a Audi 012 might not last too long doing 0-60 or 1/4 mile runs but could go many many miles on city streets. A bit more info on the application is needed to make good recomendations. I saw a V8 on a VW bug trans that went about 10k miles but its new owner only made it part way down the drag strip. But considering this is a GT40 site, putting around getting groceries is not what we want to do.
I am going to use a 012 (G86-00) behind my Lexus V8 apparently the box is rated to 380nm which is close to what the engine is quoted as stock to produce (probably generous). On the other hand my car will be at least 500lb lighter than a Boxster. So I expect it to survive well enough. If it fails I'll buy another one as they're cheap and try to improve the situation.
Looking at this I see some G50's were rated as low as 300nm so which ones are better than the 012?
I also see people doing upgrades such as oil coolers etc on their trans to get them to hold together. What would preclude this sort of thing also being done for the 012? I intend to fit an oil temp guage to mine to start with at least so have some idea whats going on in there.
check out post 20 & 23 on this thread.
Looking at this I see some G50's were rated as low as 300nm so which ones are better than the 012?
I also see people doing upgrades such as oil coolers etc on their trans to get them to hold together. What would preclude this sort of thing also being done for the 012? I intend to fit an oil temp guage to mine to start with at least so have some idea whats going on in there.
check out post 20 & 23 on this thread.
Worst case scenario it fails, you just put a Boxster S 6 speed in it. Much stronger and suited gearbox than the five.
All critical dimensions are the same except for a little extra length, and mounting/spacing is the same. I think the 6 lacks two bolt provisions that the five speed has, but is still adaptable.One thing I did forget to mention is that you'll probably start seeing the surplus of boxster gearboxes on the net(ebay, surplus sites, etc) start to get smaller. The new Spec Boxster class, and soon to be Spec Cayman class in SCCA racing means people are going to be buying up gearboxes for spares.
Still going to be far more available than G50's or audi's, but will dwindle a bit none the less, especially the six speeds.
Still going to be far more available than G50's or audi's, but will dwindle a bit none the less, especially the six speeds.
Worst case scenario it fails, you just put a Boxster S 6 speed in it. Much stronger and suited gearbox than the five.
Adam,
The only real difference in the 6 speed Boxster, is that weird one o'clock starter position. If your adapter plate uses the four o'clock Boxster 5 speed (012) starter position and pocket, then they would not interchange, AFAIK. It mostly depends on how the adapter plate is configured; it is possible though.
Right, Audi 01E (same pattern as 012). Left, Boxster 6 speed
Andy
Attachments
you're right, I did forget about that too
One of the missing bolt/dowel provisions I mentioned is actually up by the 6 speed starter.Neat trick about the 6 speed is the bellhousing can be machined/welded to put the starter over the gearbox instead of the engine. Requires a reverse rotating starter though. I have a few pictures of someone who did this on another kit car or sand rail. I'll dig them up here.
Off the top of my head no, but I have the guts of a blown one kicking around the shop somewhere. I'll try to remember to take a look for it on Monday and get that info for you.
Worst case scenario it fails, you just put a Boxster S 6 speed in it. Much stronger and suited gearbox than the five.
Boxer six, My thoughts exactly.
I think these might be the input shaft dims being looked for?
Yes, that they most certainly are! There you go Andy....Boxster S 6 speed input shaft 15/16" diameter @ 23 spline.
Good thinking Doug
