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why don't 4WD mid-engined buggies use a 4th gear?

Posted: Fri Jul 09, 2010 6:32 am
by Mr. ED
The tile says it all.
I wonder why the 4th gear is the hot set-up in mid-engined 2WD buggies but is unseen of in 4WD buggies

Re: why don't 4WD mid-engined buggies use a 4th gear?

Posted: Fri Jul 09, 2010 9:02 am
by minichamps11
There's at least one on the market. Schumacher's CAT SX 4WD buggy has been around for a few years now and was designed with a "reversed" motor via extra gears for the same reason as mid engined 2WD's.....

Re: why don't 4WD mid-engined buggies use a 4th gear?

Posted: Fri Jul 09, 2010 9:06 am
by Mr. ED
:oops: you're right, I actually remember reading that

Re: why don't 4WD mid-engined buggies use a 4th gear?

Posted: Fri Jul 09, 2010 10:08 am
by jwscab
it's probably less of a minor issue than it is for 2wd, since the chassis doesn't care which set of wheels gets the torque loading, due to the awd.

Re: why don't 4WD mid-engined buggies use a 4th gear?

Posted: Wed Jul 14, 2010 6:00 pm
by Erich Reichert
The Cat used it for layout purposes mostly. The motor was on the wrong side and two gears puts too much strain on the drive train, especially with brushless motors these days.

Re: why don't 4WD mid-engined buggies use a 4th gear?

Posted: Thu Jul 15, 2010 12:21 pm
by minichamps11
Erich Reichert wrote:The Cat used it for layout purposes mostly. The motor was on the wrong side and two gears puts too much strain on the drive train, especially with brushless motors these days.
Erich, that's not true. I spoke with both team drivers & Phil Booth during the development of the CAT SX and it was originally conceived with a high efficiency twin belt drive train, until team drivers pointed out that with the introduction of LIPO batteries off-road buggies have more then enough duration and most drivers were adding weight to cope with the brushless motor power. At this point Schumacher decided to sacrifice powertrain efficiency & lightweight design in order to optimise weight distribution & traction gain from motor torque reaction.

If it were purely a layout decision, the battery would simply be on the right hand side with the motor on the left, as per the CAT '98......

I don't understand the comment about two gears at all.

Cheers,

Ian