Scratch build Dragster style.... pre build question.

[RussH]

As the title suggests, I'm starting a scratch build, Dragster style buggy.

 

The car I'm using as a parts donor is currently 4wd, but the plan is to have 105mm wheels on the back & 85mm wheels on the front. 

 

Could I still use a 4wd setup with odd size wheels or would this cause issues, in that the rear wheel will want to travel further in one revolution than the smaller one at the front,... 

Edited June 26, 2013 by RussH

[-BEZ-]

If all of the wheels are driven you want them to have the same diameter, other wise as you said you will overdrive one end over the other, or you could do some maths and change gearing on one of the diffs to compensate

[RussH]

Thanks for confirming that Bez.

 

The way a diff works always puzzles me in that it can allow two wheels to turn opposite directions or allow one to turn faster than the other when going in the same direction. I wasn't sure if two diffs could work together at different speeds.

Edited June 26, 2013 by RussH

[Shudson]

Provided you have a centre diff, that would compensate for different size wheels, but I don't know whether juggling with oils would be able to sort out varying torque, or whether you would be stuck with most of the power going to the front (smaller wheels, therefore easier to turn).

 

In any event, when accelerating hard, even if you can prevent a full-blown wheelie, the front wheels will tend to lift and you would lose a lot of energy.

 

I suspect that may be why full size dragsters are rear wheel drive?

[mugen mark]

why do you want 4wd for a dragster?speed the name of the game 2 wheel drive will be quicker,its only for straight lines?

[RussH]

It's gong to be a dragster style rather than a full blown straight line dragster. All will become clear when I start a build thread.

 

Thanks for your input guys, very much appreaciated ..