Pantera Transmission

I had the pleasure of a short drive this afternoon in a friend's Pantera. Good 71 vintage car that is in excellent shape.

Nice handling car with reasonable power, not sure about the hp output of this particular car, I'd imagine around 350-400 flywheel with the mods, but the transmission is what got me.

The car has good power but it is largely masked by the tall ratios of the ZF transaxle. Ed indicated the car had a 4.22 diff but the ratio on each gear is really tall, the net effect being a very long-legged car.

So, it will cruise at 90mpg really well but stomping down on it in second gear doesn't produce the neck snapping acceleration you might like to have. Maybe in a 427 I'd be excited though.

Reason I mention it is there is a Pantera tranny on Ebay and unless these things can be re-geared I really wouldn't be all that excited about them. I'm told a new diff is about $4000. Shiting was not bad, but definitely heavier than I expected. For that reason I think the G50, Renault, or Audi/Getrag box is a better fit, at least for the money.

Ron

[ May 24, 2002: Message edited by: R. Earp ]

Let me clairfy - not 90mph in second.

It will cruise all day at 90mph with low revs, but when stomping down on it in say, second gear, it does not produce the neck snapping acceleration one might want because it definitely has long legs. I don't know what second it good for, but I'd reckon at least 75mph I'd guess.

I don't know about the final drive, but the ratios are very close and all tall.

Ron

Hello, !

4:22 was the standard ratio on the Pantera for many years..
Until the 3.77 came in the GT5 or so..
But there were options thou...
Mangusta, GT40 MkI "standard", roadcar, MkIII´s etc.., Pantera´s etc all used the 4:22.
Depending on model year the gear ratios differed.
A 72 up Pantera with the -2 box has alway´s been refered to as having great ratios-.
Many still want´s a higher 5th or CWP change to 3:77 or something.
These boxes, engines are built to drive on torque.
As the GT40 being a Endurance racer, not a sprint car.(at least not intended in the 60s)
MkII´s would not have made it if not torque, relaiability on high "cruising" speed.
No need for snapping shifts as main concern was able to take the torque.
Smaller, lighter and more nimble cars with smaller high revving engines are more suited for sprint or "short legged" tracks..
Like Chevrons, Lola´s etc....
At least talking 60s and 70s cars...
More cornering speed, but hey !... when the straight comes: the M8 Mclarens eat the opposition.
Or when a bunch of heavy V8´s comes on "song" down the start straight !
That´s when i feel adrenalin starts pumping..
Sorry to get off track !
Dreamt away !...

From ZF "Assembly, Maintenance, and Operating Instruction" book, standard ratios are:

for a 4.22 rear
1st gear 2.23
2nd gear 1.47
3rd gear 1.04
4th gear .846
5th gear .705

for a 3.77 rear
1st gear 2.58
2nd gear 1.52
3rd gear 1.04
4th gear .846
5th gear .740

The book also lists a 5.25 rear
1st gear 2.58
2nd gear 1.72
3rd gear 1.09
4th gear .96
5th gear .705

For the 4.22 rear and standard ratios, using a 335/35/17 (26" diameter) rear tire at 6000 rpm, speed calculates to be around 156 mph. 6K in 2nd gear should be about 75 mph.

Dave

I wasn't too far off, the rear tire is about 26.3 inches on this car according to the tape and it seemed good for the 75mph range.

Dave, how do you like the ZF in the ERA car? Weight might help it a lot, as the Panteras are somewhere in the neighborhood of 3100 pounds or more I think.

Ron

I stand corrected. Thank you all for the clarification.

As far as I know 4.22's were a BMW M1 ZF ratio. They could be installed in a Pantera but reportedly make for a rather "short legged" car--tough to imagine 90 MPH (assuming 90 MPG quoted above was a mistake) in second gear w/ 4.22's in a relatively factory original Pantera. I suspect the owner was mistaken. As for the "shiting", I think I may drop a load myself at 90mph in second gear .

Can't answer that yet Ron. The car is still in building phase. My transaxle is a 4.22 with standard ratios. Engine is a Cleveland with 2V heads and EFI. Dyno results had a torque of 385 ft-lb at 3500 with a max of 412 ft-lb and 410 HP. Should make an interesting comparison to a Pantera.

Dave

Ron, we are running a ZF 25-2 gearbox from a BMW M1 Procar in Robins GTD, but the diff has been changed to a 3.77 ratio. We run this car in competition, and it "aint no slouch". We think it has a great, very positive gearchange that we are not frightened off (if you slot it, it goes in!), and the ratios are just fine for the type of driving we do, just one cog higher than the Renaults we have been using. Frank

Add to the last message. Ratios are:- 1,2.42 2,1.61 3,1.14 4,0.846 5,0.704. Diff 3.77 Frank

Hi Guys
This is an interesting thread for me as I have finally decided I have to do something about the ratios in my M1 ZF
Transaxle.Can you picture what it's like to be on the starting grid of a race knowing the guys that you out qualified will get past before the first corner. The reason is in the final drive ratio which at 3.1 makes 1st gear so tall, i have to let the clutch out with about 2000 revs, let it hook up and then accelerate. This is a slooooow start.The other problem is a big drop from 4th to 5th.Take a look at what I've got 1st 2.23 , 2nd 1.61 , 3rd 1.31 ,
4th 1.09 , 5th .740 ring and pinion 3.2.
I've run lots of ratios on my gear calc program and have settled on changing 3rd & 4th ratio and ring and pinion.
So I'm hoping some of you guys like Frank,Gary etc might have what I need.

I need 4.22 ratio ring and pinion 9 teeth on pinion 38 teeth on crown wheel, 1.04 ratio 3rd gear, 0.846 4th gear.Gears from either a /2 pantera box or M1 will be ok.
If anyone can help I would very much appreciate it.

Regards Ross

Ross, sorry I dont have parts, but I may know a man who can, will be in touch, Frank

Frank,
Do you(or anyone else)know anything about the Tecalemit-Jackson fuel injection system that was made in the UK some years ago? I would appreciate any information any one has.
(It's for a big block Ford.
Thanks
Nathan /ubbthreads/images/graemlins/cool.gif /ubbthreads/images/graemlins/cool.gif

I assume RBT can send the parts over. www.rbttrans.com