kreb
kreb GRM+ Memberand Dork
11/13/09 12:03 p.m.

I'm sure that most of you are familiar with the lovely and innovative Citroen Traction Avant. I've had the jones' for one since seeing it in The cassic movie "Diva".

http://en.wikipedia.org/wiki/Citro%C3%ABn_Traction_Avant

I've wanted to update one into a restomod. The problem is the layout. Converting it to RWD would entail a lot of chopping, make it cramped inside, and seems somehow distrespectful. Problem is, to put a modern FWD package in there would require a longitudenal layout with the motor rear of the tranny. Are there any transaxles that can be used which would not extend very far in front of the wheels?

All input greatly appreciated

Tom Heath
Tom Heath Marketing / Club Coordinator
11/13/09 2:33 p.m.

Saab 99? It sits more or less under the engine with the clutch out front.

VClassics
VClassics Reader
11/13/09 4:18 p.m.

Saab was my first thought too, but howabout a VW type 4 engine and transaxle? Could be set up engine in front like a 914, or engine in back like various VW models.

Very cool project, in any case...

kreb
kreb GRM+ Memberand Dork
11/13/09 6:01 p.m.

In reply to VClassics: The veedub comes to mind as well, but isn't there a significant amount of mass in front of the axle? I haven't measured it, but I'd guess that the avant is only 18 inches or so from axle centerline to grille. There is a lot of engine bay between front whells and firewall though, so perhaps if one took a very short motor - say a boxer config, and close coupled the tranny and diff one could squeeze it all in there...

VClassics
VClassics Reader
11/13/09 6:32 p.m.

How are older Subarus set up, then? Only worked on one a single time years ago, but I picture the engine being mostly above the transaxle.

aeronca65t
aeronca65t HalfDork
11/13/09 6:52 p.m.

I recall seeing a TA at a hot rod show last year here in NJ.

It had a 350 Chevy engine in it. Sacré bleu!

Just dreadful!

But a modern FWD powertrain might be neat. Didn't the Chrysler LHS, Dodge Intrepid, etc have a longitudinal V6 engine with FWD? Probably zillions of them around.

DeadSkunk
DeadSkunk New Reader
11/14/09 10:37 a.m.

You could use a VW transmission and put it in front of the motor simply by taking the dif out of one side of the trans case and installing it from the other side. You end up with one forward speed and 4 reverses until you turn it back to front. Voila, 4 forward speeds and the engine is behind the trans. You can use any engine that has adaptor plates available for dune buggies. I know a water cooled VW adaptor exists. Buick V6, Subaru also.

bmw327
bmw327 New Reader
11/14/09 10:53 a.m.

In reply to DeadSkunk: Old 2wd Audis (4000, Coupe GT, VW Fox) had longitudinal engines with FWD in both 4 and 5 cyl...they were pretty tough engines, too.

DeadSkunk
DeadSkunk New Reader
11/14/09 10:58 a.m.

The only problem with almost all longitudinal systems is that the engines are forward of the transmission. If you could flip the dif in one , it would be great, but I'm not aware of a modern FWD trans where you can do that. You could put in a reverse rotation cam, but the thrust on bearings will be in the reverse direction and I suspect, the transmission would not last long.

DeadSkunk
DeadSkunk New Reader
11/14/09 11:16 a.m.

Kreb, Any idea what the car weighs? That might dictate which way to go.

kreb
kreb GRM+ Memberand Dork
11/14/09 1:11 p.m.

2200 to 2600 lbs per wikipedia. It is a unibody design and was incredibly advanced for its time.

DeadSkunk
DeadSkunk New Reader
11/14/09 1:29 p.m.

Not all that heavy. A modern twin cam of 1600 cc or more would move it along nicely. So, I say, figure out how to utilize a VW Beetle trans and any 2 litre 4 Cylinder. Hardest part would be getting the halfshafts sorted, but I'll bet the off-road community has some stuff that would work just fine. Some sort of VW trans ,fitted with output flanges and conventional CV joints hooked to the Citroen uprights. Then add some better brakes. Easy. Go for it !!

kreb
kreb GRM+ Memberand Dork
11/14/09 2:14 p.m.

In reply to DeadSkunk: I like I6s. and a long engine would look good under that long hood. I think that what you say makes sense tho.

DeadSkunk
DeadSkunk New Reader
11/14/09 3:09 p.m.

If the six would fit it would be great, but its lenghth ,plus an inline trans is going to add up. brakes would be even more critical. But a BMW six, or an I5 from a GM truck (!!!) would look cool and give it some real legs. Sooner or later you'd run into front wheel drive power limitation.

aeronca65t
aeronca65t HalfDork
11/14/09 3:39 p.m.

OK, now I realize that you need a longitudinal engine with the trans out front.

One possibility would be to use VW bus reduction axles grafted to a modern FWD longitudinal engine where the trans is behind the engine (Chrylser, Audi, etc). Then the entire setup could be rotated 180 degrees and the wheels would still turn the correct way.

On the VW bus, the reduction gears were added to give more ground clearance without redesigning the entire trans. The axles spin "backwards" in a bus. You can see the reduction gear housings at the end of each axle in the picture below.

VClassics
VClassics Reader
11/14/09 5:08 p.m.

Those reduction gearboxes were used through '67 on VW buses. '68-on has true independent suspension using CV joints, and the axles spin forward.

DeadSkunk
DeadSkunk New Reader
11/14/09 5:12 p.m.

You would have to use an electric fan, because the "normal" fan would be next the firewall. The shift linkage would look much like the one in a Formula Vee, but in reverse.

DeadSkunk
DeadSkunk New Reader
11/14/09 5:13 p.m.

You would have to use an electric fan, because the "normal" fan would be next the firewall. The shift linkage would look much like the one in a Formula Vee, but in reverse.

BoxheadTim
BoxheadTim GRM+ Memberand Reader
11/15/09 2:34 a.m.
kreb wrote: In reply to DeadSkunk: I like I6s. and a long engine would look good under that long hood. I think that what you say makes sense tho.

You know that they made a 15CV with an I6? Very rare though.

I have a vague recollection that there are a couple of French cars with a similar engine/transmission layout but the only one I keep coming up with is the Renault R4. And I doubt that that would be an improvement over the existing engine.

I'd think a Porsche 915 or G50 is probably too long but at least with that one the engine would be in the right place.

NOHOME
NOHOME Reader
11/15/09 9:28 a.m.

Dad always said "If you gonna travel on the Titanic, might as well go first class"

Transaxle out of a porshe. Little bell housing adapeter magicfrom a company called "Renegade" and a lump of GMs finest LS1 aluminium greatness bolted to the end.

How could you go wrong?

kreb
kreb GRM+ Memberand Dork
11/15/09 11:57 p.m.

In reply to NOHOME: A lot could go wrong. I want to update the mechanicals to make it a more pleasing driver, not pull 12s at the drags!

I need to pull a measurement from the front axle forward. The above pic showing the veedub transaxle makes it look pretty short. There's hope!

DeadSkunk
DeadSkunk New Reader
11/16/09 11:30 a.m.

Kreb, Remember to allow a few extra inches for the shift linkage on the VW tranny. I'm guessing 3" would be enough on top of the measured length.

Ian F
Ian F HalfDork
11/23/09 2:51 p.m.

Maybe an Audi I-5 from the 80's? I forget the details, but I seem to recall the FWD versions (Coupe GT & 4000) used a transmission behind the engine with a driveshaft up to a front diff?

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