had a bit of a thought for a project car

what would be the pros and cons of turning a front wheel drive transverse gearbox through 90deg- running two driveshafts from the drive flanges to a front and rear diff?

 

well a transfer box reduces the power to the front by a set ratio.....sending 1/2 the power to the front would probably make it drive funny...

Also if its open diff fwd gearbox then it'd be horrible if any of the 4 wheels broke traction...if it was a lsd box it'd also drive funny when traction btoke as the diff would lock possibly putting extra stress on things.

Thridly theyre normally weak when only driving 2 wheels the way they should..

I'm not sure if its a good idea really myself...if it was a simple setup i'd have seen one already

Hope that helped a bit and not just thrown spanners in the works..

Dan

 

I know.......use a mid engined 4x4 cossie lump...with a short prop to rear and a looooong prop to the front (obviously you'd need to use a 2wd sump for prop clearance......

Front diff would have to be bespoke i'm affrad or you could modify a 4wd sump and diff to run up front....(they're designed for oil to be in the sump though I think so might pose probs doing it this way.

Dan

 

its just ideas at the moment

my thought was to use an atb diff in the box- should send most of the power to the rear if there is any traction loss as it would most likely be the front- use an lsd for the rear diff and open front

i know ther are physically weaker than rwd/4wd boxes but there are some hight powered fwd cars about these days

was thinking it was too simple to work myself

 

thought of that too but the layout would be very long at the back ie engine then box then diff
front is less of a problem as you could use a rear diff turned upside down at the front

 

no easy solution really....trouble is you cant really create a decent driving car with just normal diffs if its 4x4... you need a transfer box to split the power as you dont really want a 50/50 power split (which you would get with out a transfer box.

I know the cossie 4x4 setup is long but you thought about having the engine instead of a passenger seat?

Dan

 

the prop might have to be at a big angle, or the engine may have to be on one side of the car... alternatively, you could have the diffs over one side.

also, think about the fianl drive/ diff ratio's... you'd have lets say a 4.1:1, plus whatever the diff ratios would be.

lots to think about

 

the other option was to have a something like 2wd inline engine and box turned through 180deg and placed in the middle of the car so that the gear box would be in the trans tunnel- then fit in a transfer box to send power to front and rear

problem here would be to find a transfer box that could do this

 

PMSL

Mate, if you turn it through 180 degrees you will have 6 reverse gears and 1 forward

 

handy for parking

 

I wanted to do this using a calibra turbo gearbox and transfer box, turned 180 degrees so i have 6 reverse gears but then run an H22a honda engine that runs the other way around, but I was reliabley informed the helicals wouldnt like being spun backwards

Shame cause it would have been a doddle to do in my car and the gearbox is ideal cause it would end up rwd/4wd electronically selectable and also only normally transfer power to the front to pull out of a bend once the rear had started to slip.

ah well

 

but i was thinking of using 2x 2wd rear diffs, these could be turned upside down if need be to drive the corect way (still run in the same direction but will drive in opposite direction)

 

i dont think you have though much about how the rear diff would fit into the fwd casing

 

why would it need to go into a fwd casing

 

as long as the engine\box you are turning 90 degrees has a LSD in it, it would work in theory, as long as the diffs were the same ratio

 

well thats what i was thinking- the strength of the box is the only major issue as far as i can see