Real ineresting thread this.
I decided to do a bit more research so googled for 'bmw M1 ZF gearbox', and unearthed this old post on the pantera forum:
[ QUOTE ]
Pantera East has signed an exclusive contract to provide Pantera owners =
with Transaxle Ring Gears ("cruise" ratio of 3.77 prox) in 9310 material =
(better than even the original). Gearset will be pre-lapped (run-in) =
and engraved with setup information for correct installation. As you =
may know current Retail price for ZF Ring Gears is close to $3,000. Our =
price will be $1950. However if we can get deposits for 20 pieces we =
could do $1600 ($350 savings from an already drastically reduced =
price). Hurry, once the order is completed we will not be able to =
increase production to get a better price.
Also available will be an overdirve 5th gear (.655). Made from 9310 =
material and guaranteed perfect (some factory gears have been showing up =
out of round, making for some hellatious racket. Current retail price =
is $1,300-1,500. Our price will be $995. However, if we can get =
deposits for 20 pieces we could do $890 (an additional $105 savings).=20
Feed back is appreciated. Remember time is limited to finished =
production. Order yours today. Only $500 holds one or both.
One more thing! A very limited quantity of NOS BMW M1 gearboxes have =
been located and purchased ready for sale. As you know this transaxle =
is the latest version of the ZF type "-2" updated by ZF to BMW =
specifications. Improved syncros (smoother shifting), stronger bullet =
proof case (gusseted for added strength in critical locations), CV =
output flanges (makes an especially simple and low cost conversion to CV =
drive axles, etc. are a few of the benefits. Perfect for ultra high =
performance GT40 conversions and can be used in a Pantera by "flipping" =
the Ring & Pinion. Cost "less than half of what you'd expect". =
Inquire!
Marino
[/ QUOTE ]
Note that Marino states this late -2 box is "Perfect for ultra high performance GT40 conversions"
Heres another from http://realbig.com/detomaso/1999-04/500.html :
[ QUOTE ]
> I've also heard the M-1 case is stronger, although we
already know from Jr Wilson the early case will take 900 horsepower, so whats
the use?
>>>Dash-1 gearbox cases as well as some Dash-2 cases suffer a chronic
weakness in cars that subject them to high horsepower and high load factors.
Eventually the case fatigues and right at the junction where the flat top of
the case angles up to meet the bellhousing, a crack develops, which then
heaves all the oil overboard and quickly toasts the internals.
This is NOT a factor for street-driven Panteras, just all-out race cars with
mega-power and beaten hard. Junior was relatively gentle with his gearboxes
because all he ever did was accellerate to speed and then keep it there.
Road course use, banging up and down gears again and again is what does 'em
in. In fact, didn't John Parsons blow up his ZF case that way?
The M-1 case is substantially stronger due to massive webbing being cast into
this weak spot. Essentially bulletproof, and somewhat essential for any
600+horsepower dedicated track car.
[/ QUOTE ]
Maybe it is worth looking for on of these boxes that have the extra strengthening ??
Oh, and the search also pulled up a post from Ross about his ZF ratio swapping I'd missed /ubbthreads/images/graemlins/wink.gif
http://www.gt40s.com/ubbthreads/showflat.php/Cat/0/Number/47267/an/0/page/0
I decided to do a bit more research so googled for 'bmw M1 ZF gearbox', and unearthed this old post on the pantera forum:
[ QUOTE ]
Pantera East has signed an exclusive contract to provide Pantera owners =
with Transaxle Ring Gears ("cruise" ratio of 3.77 prox) in 9310 material =
(better than even the original). Gearset will be pre-lapped (run-in) =
and engraved with setup information for correct installation. As you =
may know current Retail price for ZF Ring Gears is close to $3,000. Our =
price will be $1950. However if we can get deposits for 20 pieces we =
could do $1600 ($350 savings from an already drastically reduced =
price). Hurry, once the order is completed we will not be able to =
increase production to get a better price.
Also available will be an overdirve 5th gear (.655). Made from 9310 =
material and guaranteed perfect (some factory gears have been showing up =
out of round, making for some hellatious racket. Current retail price =
is $1,300-1,500. Our price will be $995. However, if we can get =
deposits for 20 pieces we could do $890 (an additional $105 savings).=20
Feed back is appreciated. Remember time is limited to finished =
production. Order yours today. Only $500 holds one or both.
One more thing! A very limited quantity of NOS BMW M1 gearboxes have =
been located and purchased ready for sale. As you know this transaxle =
is the latest version of the ZF type "-2" updated by ZF to BMW =
specifications. Improved syncros (smoother shifting), stronger bullet =
proof case (gusseted for added strength in critical locations), CV =
output flanges (makes an especially simple and low cost conversion to CV =
drive axles, etc. are a few of the benefits. Perfect for ultra high =
performance GT40 conversions and can be used in a Pantera by "flipping" =
the Ring & Pinion. Cost "less than half of what you'd expect". =
Inquire!
Marino
[/ QUOTE ]
Note that Marino states this late -2 box is "Perfect for ultra high performance GT40 conversions"
Heres another from http://realbig.com/detomaso/1999-04/500.html :
[ QUOTE ]
> I've also heard the M-1 case is stronger, although we
already know from Jr Wilson the early case will take 900 horsepower, so whats
the use?
>>>Dash-1 gearbox cases as well as some Dash-2 cases suffer a chronic
weakness in cars that subject them to high horsepower and high load factors.
Eventually the case fatigues and right at the junction where the flat top of
the case angles up to meet the bellhousing, a crack develops, which then
heaves all the oil overboard and quickly toasts the internals.
This is NOT a factor for street-driven Panteras, just all-out race cars with
mega-power and beaten hard. Junior was relatively gentle with his gearboxes
because all he ever did was accellerate to speed and then keep it there.
Road course use, banging up and down gears again and again is what does 'em
in. In fact, didn't John Parsons blow up his ZF case that way?
The M-1 case is substantially stronger due to massive webbing being cast into
this weak spot. Essentially bulletproof, and somewhat essential for any
600+horsepower dedicated track car.
[/ QUOTE ]
Maybe it is worth looking for on of these boxes that have the extra strengthening ??
Oh, and the search also pulled up a post from Ross about his ZF ratio swapping I'd missed /ubbthreads/images/graemlins/wink.gif
http://www.gt40s.com/ubbthreads/showflat.php/Cat/0/Number/47267/an/0/page/0