Discussion
The G50/52 is your man although, and as you probably know, has an LSD (and a larger crown wheel) but they are rare. It is also woth noting that if the motor you intend to use makes big torque low in the RPM range, even this may be marginal. Folk will tell you that any G50 is unburstable but this is not so. There are also a few firms in the States that supply uprated parts but being as the word Porsche is involved, they aint cheap.
As far as I know, the G50/50 is known to be the strongest built G50. It´s the gear box which was used in the 1989 911 turbo. The 1989 911 Turbo supplied 300 (german) HP, 432,4 NM (about 318,9 lb-ft) Torque and 1989 weighted 1335 kg. A GTR is around 1000kg, so 335kg less, that benefits you...The second thing on your side is, that our germany engineers have the character to always engineer something twice as strong as it is needed. That might have smth. to do with the TÜV authority... :-) That means, it is for sure, that a G50/50 is capable of handle more than 320 lb-ft...But the more you go up, the closer you get to the limit..and if you exceed it you may find yourself dancing a waltz at 150 mp/h....
Why don´t you think about a G64/51, the gearbox which was used in the 993 Turbo, which supplied up to 430 HP (was a tuning kit Porsche offered ex factory) with a 560 NM (413 lb-ft). The car weighted 1500 kg...so 500 kg more than a GTR....So I think this Gear box is much closer to the forces you going to put on it.... It´s a 4wd, but can be changed to a 2wd quite easily....For more Info see my thread from Aug 4th "G64/51, 993 Porsche TT Gear Box in an GTR ?" here in the Forum....
Concerning the audi gear boxes: All really powerful audi cars are only delivered with automatic transmission, for ex. the S8...Each of these cars was a quattro (4wd) ! . The only cars with man. trans. are the 4 S and RS cars. The strongest of them is/was the RS4 with a 420 HP and 430 NM (like the 930 Turbo mentioned above)...This cars have a 6-Speed man.trans. but 4WD...So I don´t think you´ll find a Audi gearbox which suits your needs!
Why don´t you think about a G64/51, the gearbox which was used in the 993 Turbo, which supplied up to 430 HP (was a tuning kit Porsche offered ex factory) with a 560 NM (413 lb-ft). The car weighted 1500 kg...so 500 kg more than a GTR....So I think this Gear box is much closer to the forces you going to put on it.... It´s a 4wd, but can be changed to a 2wd quite easily....For more Info see my thread from Aug 4th "G64/51, 993 Porsche TT Gear Box in an GTR ?" here in the Forum....
Concerning the audi gear boxes: All really powerful audi cars are only delivered with automatic transmission, for ex. the S8...Each of these cars was a quattro (4wd) ! . The only cars with man. trans. are the 4 S and RS cars. The strongest of them is/was the RS4 with a 420 HP and 430 NM (like the 930 Turbo mentioned above)...This cars have a 6-Speed man.trans. but 4WD...So I don´t think you´ll find a Audi gearbox which suits your needs!
Thanks, much appreciated. I only thought of the G50/50 as it seems to be quite popular. The G64/51 seems a better bet.
How much do I need to pay top get these and where from ? There's a number of companies advertising second hand spares but as was said above, the word Porsche seems to mean more expensive than is perhaps justified. My engine will rev out at 7500 or so and will be turbocharged so the stock gear ratios/final drive will probably be OK.
I looked at the Hewland web site and they had a number of transaxles that would take 600 lb ft but when I saw the prices, I thought they were quoting the price for 5 or 6 to a crate, not 1 !
How much do I need to pay top get these and where from ? There's a number of companies advertising second hand spares but as was said above, the word Porsche seems to mean more expensive than is perhaps justified. My engine will rev out at 7500 or so and will be turbocharged so the stock gear ratios/final drive will probably be OK.
I looked at the Hewland web site and they had a number of transaxles that would take 600 lb ft but when I saw the prices, I thought they were quoting the price for 5 or 6 to a crate, not 1 !
It is not a quite easy thing to get a G64/51. Here in germany a used but perfectly working G64/51 would be around 4-6000 Euro (5.1k to 7.7k $). The conversion should be around 2k-3k $. Conversions are done by f.e. Bobby Heart at California Motorsports, Bob Watson Racing at Middle Aston , Banbury , Powerhaus II...They don´t just do conversions, they also have the gear boxes.... . A further hint would be www.quaife.co.uk/catalogue/page58.htm but hey, thats 9.999 GBP (18.8k $ :-))), a sequential 6-Speed, quite unburstable.... A german porsche dealer offered me a Carrera GT gear box, 6 Speed, "used" to 612HP....he wanted ca. 8k $ for it....if you want, I can get you a contact....
lvjost said:
A further hint would be www.quaife.co.uk/catalogue/page58.htm but hey, thats 9.999 GBP (18.8k $ :-))), a sequential 6-Speed, quite unburstable....
I've spoken to Quaife about these, and they were very hesitant to suggest their suitability for a Chevy powered Ultima. Most of the stuff they do only has BHP ratings, never a torque rating which is more relevant.
I have a G50/21, 6 speed with a Quaife ATB LSD, and apart from a few sticky shifts courtesy of the long rod shifter mechanism it's fine.
As you all probably know by now, Peter Knight built my motor and when I first made his acquaintance he had not long finished building the motor for the Blower Motorsports Ultima that never really seemed to get of the ground and was recently sold at auction at a fraction of the build cost. Well, here's the rub, apparently said Quaife type sequential box was fitted to this project but was quite often the weak point in the reliability stakes race wise. By the time Blower decided for one reason or another to chuck it in, Quaife had sorted the box. This is only here say of course, but in theory, Quaife has done the R & D on the box to be able to say it is O.K. for a given torque spec. (or so one would imagine).
my g50/50 built by powerhauseII www.phii.net is standing up to 530lbs at the rear wheels. give roger at call they have build several boxes for ultima.
mark
mark
In essence G what you say is indeed correct apart from the fact that;
1/ They are at this precise moment in time putting said box through evaluation and so it is not yet available for general release
2/ At this stage they will not give an exact torque handling figure but are saying it 'should' handle 600ftlbs+
3/ It is likely to cost 7/8K depending on spec. (LSD, internal oil pump etc.)
4/ It will be 6 speed although you may be able to have it as a 5 but it will cost the same
5/ It is fully sequential
6/ At the moment it weighs 80kg but they should be able to get this down to 70/75 by the time it goes into production
7/ You can specify any ratios you fancy (within reason) as they intend to make batches of popular gear sets as and when they are asked for them, and it will be included in the cost
Should be available in about 3 months.
1/ They are at this precise moment in time putting said box through evaluation and so it is not yet available for general release
2/ At this stage they will not give an exact torque handling figure but are saying it 'should' handle 600ftlbs+
3/ It is likely to cost 7/8K depending on spec. (LSD, internal oil pump etc.)
4/ It will be 6 speed although you may be able to have it as a 5 but it will cost the same
5/ It is fully sequential
6/ At the moment it weighs 80kg but they should be able to get this down to 70/75 by the time it goes into production
7/ You can specify any ratios you fancy (within reason) as they intend to make batches of popular gear sets as and when they are asked for them, and it will be included in the cost
Should be available in about 3 months.
That's the standard price from the Porker parts importers over here for that box (G96/88?).
Ulimacz has one in his - or did, with a 3rd party sequential converter, he says it's fine except for a jumpy 2nd? gear which is a common fault apparantly.
Also, if it's from a GT3, then it'll probably be geared for a revy NA porker motor, so not so good if your redline is sub 6k rpm.
This is what you really want, althought it's somewhere around 2x the price of that Porker box...
www.gearfox.co.uk/transmissions.html
Ulimacz has one in his - or did, with a 3rd party sequential converter, he says it's fine except for a jumpy 2nd? gear which is a common fault apparantly.
Also, if it's from a GT3, then it'll probably be geared for a revy NA porker motor, so not so good if your redline is sub 6k rpm.
This is what you really want, althought it's somewhere around 2x the price of that Porker box...
www.gearfox.co.uk/transmissions.html
look at my post several posts up, I really do feel this may be the way to go. My G50 03 re built and totally re geared with all the kit from Powerhaus cost approx 6/6.5K including the original box so I don't think 7/8K for a 6 speed sequential box with your own choice of ratios is a million miles away.
GTWayne said:
look at my post several posts up, I really do feel this may be the way to go. My G50 03 re built and totally re geared with all the kit from Powerhaus cost approx 6/6.5K including the original box so I don't think 7/8K for a 6 speed sequential box with your own choice of ratios is a million miles away.
Especially if the miracle box that you are talking about could let you use a cheaper clutch, ring gear, starter and could do away with the need for an adaptor plate. Factor these into the cost when comparing them to the Porsche parts and the price may come down a bit
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