Mid Engine AWD, Front Gearbox?
Discussion
I know this has been covered before but has anyone successfully done it or seen it done running the transaxle in front of the engine?
All that I can think of is the Audi R8 & Lambos which use the Oerlikon Graziano gearbox, but the stock gearing is crap sadly for a relatively low-revving engine.
A little background, tube chassis build, Lexus 4.3 V8 (future twin turbo) so Porsche trans would have been the go-to but they're both rare and expensive.
Doing this the gearbox choice is broader and cheaper, although I admit i know little about running a transfer case and separate diff (as far as suitable choice goes, for a road/track car with potentially over 600whp)
Despite being somewhat heavier, the mass of the drivetrain would be considerably better centered (bear in mind a standard transaxle has some 90% of its mass behind the axle!)
I figure it could be configured as a RWD only setup initially, then add on a diff, propshaft and front diff.
for this out of curiosity...
All that I can think of is the Audi R8 & Lambos which use the Oerlikon Graziano gearbox, but the stock gearing is crap sadly for a relatively low-revving engine.
A little background, tube chassis build, Lexus 4.3 V8 (future twin turbo) so Porsche trans would have been the go-to but they're both rare and expensive.
Doing this the gearbox choice is broader and cheaper, although I admit i know little about running a transfer case and separate diff (as far as suitable choice goes, for a road/track car with potentially over 600whp)
Despite being somewhat heavier, the mass of the drivetrain would be considerably better centered (bear in mind a standard transaxle has some 90% of its mass behind the axle!)
I figure it could be configured as a RWD only setup initially, then add on a diff, propshaft and front diff.
for this out of curiosity...
Could easilly be changed by inverting the diffs or yeah swapping front rear although I have no ideas yet in which I'd use.
Porsche box gets used all the time, the gearbox is both upside down and the wrong way around, giving 4/5/6 forward gears etc as normal. The trouble is a good one is £7k+. Most transaxles are either too weak, the wrong way up (driveshafts under the input shaft which would put the engine undesirably high) or just crazy money.
BMW gearboxes are getting popular for UZ-FE conversions for being cheap and strong, and they're surprisingly compact too, which led me to start considering this layout again
Porsche box gets used all the time, the gearbox is both upside down and the wrong way around, giving 4/5/6 forward gears etc as normal. The trouble is a good one is £7k+. Most transaxles are either too weak, the wrong way up (driveshafts under the input shaft which would put the engine undesirably high) or just crazy money.
BMW gearboxes are getting popular for UZ-FE conversions for being cheap and strong, and they're surprisingly compact too, which led me to start considering this layout again
The off road boys have been doing this for donkeys! Way back in the early 90's we were building buggies with rear mounted RV8s, pointing forwards, running a saloon car box, and a short prop to the xfer case under the front bulkhead, and a prop all the way back to the rear diff, using axles with the centres cut out and flipped.
The issue in a small car is always that the big bell housing is right where the occupants butts need to be, rather than where their feet are, which forces a wide apart seating layout.
Andy Burtons PugCossy had similar layout, as did the metro 6R4 of course:
The issue in a small car is always that the big bell housing is right where the occupants butts need to be, rather than where their feet are, which forces a wide apart seating layout.
Andy Burtons PugCossy had similar layout, as did the metro 6R4 of course:
stevieturbo said:
chuntington101 said:
Are there any cheaper gearboxes like the GTRs that would incorporate a gearbox, transfer case and front diff in a single unit? Would make the install a little easier regarding the passenger area.
GTR's do not do thatIt you ran it in the opposite orientation It would still require the gearbox to be in the way but would be where a normal gearbox would be on a front engined RWD car.
chuntington101 said:
The new ones do it the other way around. Engine front and gearbox, centre diff, etc. in the rear.
It you ran it in the opposite orientation It would still require the gearbox to be in the way but would be where a normal gearbox would be on a front engined RWD car.
New GTR's run a rear transaxle type arrangement. But they still require a front diff. They are also inherently RWD with a clutch pack to send drive to the front. So not really a centre diff in the usual sense.It you ran it in the opposite orientation It would still require the gearbox to be in the way but would be where a normal gearbox would be on a front engined RWD car.
To try and reverse one of those would be a lot of work.
Older GTR's are much like his drawing, old Fords etc etc
early countach did this.
http://craigsteffen.net/blog/car/2012/04/images/lt...
and diablo vt added the front drive
http://www.lambocars.com/images/diablo/diavt5.jpg
http://craigsteffen.net/blog/car/2012/04/images/lt...
and diablo vt added the front drive
http://www.lambocars.com/images/diablo/diavt5.jpg
Toltec said:
Yes, holy thread reboot batman.
Weird idea, if you took a transverse engine and gear box and turned it longitudinally could you feed the output shafts to additional differentials at the front and rear?
This is sort of the concept of what the Peugeot 205-T16 did - basically a mid/rear mounted transverse 4-cylinder engine with an adapted transaxle-type gearbox also mounted transversely which used its "left" and "right" differential outputs to go to the front and rear differentials (if I recall correctly).Weird idea, if you took a transverse engine and gear box and turned it longitudinally could you feed the output shafts to additional differentials at the front and rear?
Group B had a few interesting ideas, the Ford RS200 was mid/rear longtitudinal engine driving a gearbox at the front of the car which then drove back to the rear differential. The theory was it was good for weight distribution.
Toltec said:
Yes, holy thread reboot batman.
Weird idea, if you took a transverse engine and gear box and turned it longitudinally could you feed the output shafts to additional differentials at the front and rear?
Yes, if you wanted to build a rock crawler you could do exactly that. With two lots of final drive reductions it won't be so good for anything fast, unless you can find front and rear diffs with 1:1 ratios.Weird idea, if you took a transverse engine and gear box and turned it longitudinally could you feed the output shafts to additional differentials at the front and rear?
Toltec said:
Weird idea, if you took a transverse engine and gear box and turned it longitudinally could you feed the output shafts to additional differentials at the front and rear?
Lohr FL500 - French military vehicle. In production and service in the 70s.2cv engine and box, turned 90deg. One driveshaft going for'ard, one aft'ard.
They're quite a lot of fun to drive. There's a centre difflock - belts off each output shaft to a layshaft, which is then pulled taut to "lock"...
Edited by TooMany2cvs on Friday 3rd August 15:51
Mr2Mike said:
Toltec said:
Yes, holy thread reboot batman.
Weird idea, if you took a transverse engine and gear box and turned it longitudinally could you feed the output shafts to additional differentials at the front and rear?
Yes, if you wanted to build a rock crawler you could do exactly that. With two lots of final drive reductions it won't be so good for anything fast, unless you can find front and rear diffs with 1:1 ratios.Weird idea, if you took a transverse engine and gear box and turned it longitudinally could you feed the output shafts to additional differentials at the front and rear?
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