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what is stopping you chain driving a centre diff
bigbravedave - 29/6/06 at 08:45 PM

Exactly as the subject asks? whats stopping you chain driving a centre diff, and running a rather angled propshaft front and rear.

My next project (always good to start one before finishing the current!) is an off/on road bike engined buggy and with bike engines getting taller and narrower I was thinking along the lines of a rear engined inline r6 lump chain driving a center diff and attempting to package a pair of props/diffs front and rear. Yes It sounds all a bit ott but It works so well on radio controlled buggies, Id like to scale it up a bit! something like this if the pic doesnt attach: http://www.off-road.com/rc/mugenxr/decomposablediffmount2.JPG Rescued attachment rc center diiff.jpg
Rescued attachment rc center diiff.jpg


JoelP - 29/6/06 at 08:47 PM

no problem there. Have you seen the dp1 project? Not a million miles from what you describe.


bigbravedave - 29/6/06 at 08:55 PM

Yes that layout did cross my mind But I wanted a more central driving position and without the chain tension and backlash issues, Im a powertrain design engineer in the construction industry and have come accross a couple of suitable compact hydraulic pumps and motors for hydrostatic front drive with conventional chain rear drive, only problem is the hydrostatic would struggle to react as quickly as the chain drive, the inefficiency of it would offer some bias however


mark chandler - 29/6/06 at 09:10 PM

All range rovers post around 1991 have chain driven transfer boxes, no problem at all doing this in theory.

In practice a locked diff would be no good on road (only works in straight line, turn a bend and get excessive torque steer), an open diff defeats the object (all power could go to front or back, the first wheel to spin) so you need a LSD in the middle.

Regards Mark

[Edited on 29/6/06 by mark chandler]


matty_64 - 29/6/06 at 09:21 PM

a sierra 4x4 transfer box may be useable.chain driven & very cheap


bigbravedave - 29/6/06 at 09:24 PM

ahh... I can see corners quickly becoming a problem, Ive driven front wheel drive stuff with atb diffs fittted, in the wet at low speeds you can pile on the power and they go straight on , so that coupled to a stiff diff in the centre would be hidious! so realistically it would have to be lsd throughout, how long do you rekon a viscous pack would last in a center diff!?