tegwin
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| posted on 28/12/07 at 11:30 PM |
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Another silly moment....Front engine rear gearbox?
Just another one of those questions that bounces around in my head from time to time..
You hear some car manufacturors talking about mounting the engine up front and the gearbox in the boot to give perfect weight distribution etc....
Presumably this means that you have to have a stonking great propshaft spinning at engine speed linking the engine to the gearbox...
Now my crazy question is this: Could it be done safely and cost effectivley in a kit car?
Something like the VAG 2.6 V6 and a transaxle?
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oadamo
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| posted on 28/12/07 at 11:35 PM |
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it could be done but the clutch would be a pain to sort out.
adam
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worX
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| posted on 28/12/07 at 11:41 PM |
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You can always supercharge the 2.5 Porsche engine (relatively) easily. And it lives in the 944 in the same configuration that you already want -
Engine front and Gearbox rear!
Steve
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oadamo
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| posted on 29/12/07 at 12:14 AM |
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quote:
Originally posted by worX
You can always supercharge the 2.5 Porsche engine (relatively) easily. And it lives in the 944 in the same configuration that you already want -
Engine front and Gearbox rear!
Steve
i didnt even no that there was cars out there with that sort of setup.
adam
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dave-69isit
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| posted on 29/12/07 at 12:33 AM |
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alfa juileta
had same arangment
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Jesus-Ninja
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| posted on 29/12/07 at 12:45 AM |
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quote:
Originally posted by tegwin
Presumably this means that you have to have a stonking great propshaft spinning at engine speed linking the engine to the gearbox...
In this arrangement it's known as a torque tube. Typically one tube spinning inside another.
As commented. 944, 968 etc have this set up.
I know chuff all about 7-esque cars, but surely the idea of the chassis design is that it puts the drivers weight over the rear wheels, the engine
inside the front axle, and consequwntly the gearbox lies somewhere in the middle anyway, so weight distribution should be much closer to 50 / 50
anyway.
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iank
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| posted on 29/12/07 at 12:53 AM |
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Volvo 300 series (340, 360) also has the same arrangement (also had a de-dion axle).
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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Volvorsport
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| posted on 29/12/07 at 01:06 AM |
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volvo 340 with de dion (heavy) , arse sits right on the gearbox , needs a wider chassis , beleive me i tried this .
you could try adapting a transaxle gearbox by taking the bellhousing off , which is what i was going to do - why go to all that bother , make it mid
engined !!!
www.dbsmotorsport.co.uk
getting dirty under a bus
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kb58
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| posted on 29/12/07 at 02:11 AM |
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I believe Porsche 944 did that, along with Chevy Corvettes.
Mid-engine Locost - http://www.midlana.com
And the book - http://www.lulu.com/shop/kurt-bilinski/midlana/paperback/product-21330662.html
Kimini - a tube-frame, carbon shell, Honda Prelude VTEC mid-engine Mini: http://www.kimini.com
And its book -
http://www.lulu.com/shop/kurt-bilinski/kimini-how-to-design-and-build-a-mid-engine-sports-car-from-scratch/paperback/product-4858803.html
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onzarob
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| posted on 29/12/07 at 07:29 AM |
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Alfa 75 and Z1 has the gearbox in the back as well 
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zilspeed
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| posted on 29/12/07 at 09:16 AM |
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You will find a build using an Alfa transaxle on the ESTfield website. They do state quite clearly that it was necessary to raise the seating position
to accomodate the bellhousing.
That's a killer for me - in a seven, the seat must be as low as possible or you've completely compromised the whole car.
(That said, I am err 'big boned', so ignore the bit above.)
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Volvorsport
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| posted on 29/12/07 at 10:45 AM |
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ferrari 275 also .
www.dbsmotorsport.co.uk
getting dirty under a bus
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t.j.
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| posted on 29/12/07 at 11:57 AM |
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alfa had also the diskbrakes bolted on to the gear-box to reduce the unsprung weight.
volvo 340 did it with the gear-box in the rear. but mostly there was a cvt in it.
Please feel free to correct my bad English, i'm still learning. Your Dutch is awfull! :-)
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coozer
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| posted on 29/12/07 at 12:13 PM |
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Aston Martin DB9? Nice big V12
1972 V8 Jago
1980 Z750
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Aico
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| posted on 29/12/07 at 12:47 PM |
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The new GTR Wouldn't a Quaife diff be best? I thought I say one converted into a single seater. It's a diff, but it also has gears in
it etc. Zcars also had one made by a different manufacturer for the Elise Hayabusa conversion. Diff with reverse and gears.
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TheGecko
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| posted on 29/12/07 at 01:26 PM |
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quote:
Originally posted by tegwinPresumably this means that you have to have a stonking great propshaft spinning at engine speed linking the
engine to the gearbox...
Now my crazy question is this: Could it be done safely and cost effectivley in a kit car?
If you think about it, once you put the an average gearbox in 4th or 5th, then the ratio is 1:1 or beyond so the propshaft will be over the
engine speed anyway. As others have said above, plenty of manufacturers have done this, so no big deal in terms of innovation etc.
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matt_claydon
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| posted on 29/12/07 at 02:48 PM |
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The propshaft (torque tube) could be considerably smaller than a normal one as you are only transmitting the engine torque. In a conventional setup
you are transmitting (maximum) the engine torque multiplied by whatever the first gear ratio is. Probably about four times the engine torque.
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speedyxjs
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| posted on 29/12/07 at 06:46 PM |
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quote:
Originally posted by oadamo
it could be done but the clutch would be a pain to sort out.
adam
Shouldnt be too bad if it was hydraulic
How long can i resist the temptation to drop a V8 in?
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thomas4age
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| posted on 29/12/07 at 11:32 PM |
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shaft is then called "torque tube" for some reason, but loads of cars have that.
want something interesting look at the layout of a lambo 4wd (not the hidious offroad)
grtz thomas
If Lucas made guns, Wars wouldn't start either.
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iank
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| posted on 30/12/07 at 12:12 AM |
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quote:
Originally posted by thomas4age
shaft is then called "torque tube" for some reason, but loads of cars have that.
want something interesting look at the layout of a lambo 4wd (not the hidious offroad)
grtz thomas
Don't they do something semi mad like running a prop through the engine block (or was it the sump)?
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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thomas4age
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| posted on 2/1/08 at 07:56 AM |
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Lambo mid engined.
the engine is mounted in the car in reverse position, clutch facing forward, then a more or less normal 4wd gearbox is attached to the engine with the
case and tailhousing in a normal transmissiontunnel,
theres a narrow build transfercase on the rear of the box from where there goes a prop to the front diff, and a prop through the side of the engine
and a part of the sump through the back axle behind the engine, another diff there provides drive to the rear wheels.
The newe lambos use a box with a centered transfercase, the front prop is on the same place as say a T9 has the shaft, but the rear axle has it's
transfer case almost right behind the flywheel this way you can build a smaller tunnel and have more interiour space.
here you can see the torque tube going to the front and on the left side of the bellhousing a protusion sits for the prop to the rear dif, the engine
lies inbetween this box and the rear diff.
 
lamborghini 4x4 gearbox
it's a real clever system and could be copied for midengine kits using very strong transmissions for little money compared to a G50 or such that
you would use in a normal mid engine layout. and is exactly why I asked the dimensions of an MT75 4wd cossie or a T5 box.....
grtz Thomas
[Edited on 2/1/08 by thomas4age]
If Lucas made guns, Wars wouldn't start either.
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crafty
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| posted on 3/1/08 at 01:53 AM |
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Hmm.... Ive just finished an Ultima GTR and have been looking at various layouts for my next project. I'm quite taken with the Audi V8 -
there's a few tasty Ultimas with this engine/trans.
Here's a few pics of various layouts.
Note that if the Audi package were put in a rear engine car, the engine would be hanging out the rear (like the Porsche)
For this reason the Nissan config may work better for a Mid engined 4WD.
The lambo layout would mean seating near the front of the car - or a wide car with seats either side of the trans. I am also yet to find a trans
similar to the Lambo that is not a Lambo box.
Not sure if the Nissan dif can be inverted, but the weight distribution is good if used front box - rear engine
Nissan GTR (front engine 4WD)
Audi (front engine 4WD)
Lambo (rear engine 4WD)
Porsche (rear engine 4WD)
Bugatti (rear engine 4WD)
[Edited on 3/1/08 by crafty]
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crafty
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| posted on 3/1/08 at 02:08 AM |
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Oh... there's also the option of rear engine + normal gearbox (facing forward) with a transfer case and front/rear diffs...
This leaves options wide open for engine/gearbox and difs, and allows you to put the engine wherever you like.... but will have a weight penalty and
affects seating position.
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kb58
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| posted on 3/1/08 at 05:47 AM |
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quote:
Originally posted by crafty
Note that if the Audi package were put in a rear engine car, the engine would be hanging out the rear (like the Porsche)
Rear engine, or mid-engine? If placed behind the seats, it seems like it works out fine. If placed behind the axle backwards, it would drive the car
backwards, so I don't think that's what you mean.
[Edited on 1/3/08 by kb58]
Mid-engine Locost - http://www.midlana.com
And the book - http://www.lulu.com/shop/kurt-bilinski/midlana/paperback/product-21330662.html
Kimini - a tube-frame, carbon shell, Honda Prelude VTEC mid-engine Mini: http://www.kimini.com
And its book -
http://www.lulu.com/shop/kurt-bilinski/kimini-how-to-design-and-build-a-mid-engine-sports-car-from-scratch/paperback/product-4858803.html
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crafty
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| posted on 3/1/08 at 08:02 AM |
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Sorry.... I wasnt very clear - I am on the hunt for 4WD.
Mid AND 4wd wont work (neatly) with the Audi drivetrain
... if its mid (engine behind seats) with trans at the rear it will obviously work as 2WD (same setup as my Ultima) but it can't be 4WD unless
you have a transfer case on the rear and a prop shaft going forwards - which would be a bit silly.
If one were to simply use the Audi drivetrain in reverse, it could be done by flipping the trans (as per the G50 in my Ultima).... but you'd
have the engine hanging out the back like a Porsche.... which is not what I am after.
I'm looking at 2 scenarios:
OPTION 1
Engine behind seats
Transaxle at front (like the Nissan)
Propshaft running back again to diff (behind engine)
To do this the Nissan trans would have to be flipped.
OPTION 2
Layout as per Nissan... but engine moved back.
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