length to wheel base ratio

barmcd wrote:

RLS7201 wrote:

barmcd wrote:

RLS7201 wrote:
Wheel base to over all length ratio is more forum/internet nonsense.
MY 95 Bounder has a ratio of .479 and it drives great! 190" wheel base, 33' long. Best thing is the turning. Then there is the diesel owners talking about rear over hang on the gassers. My gasser has a 13' over hang. Diesel pushers have a 12'+ over hang, depending on chassis. More forum/internet chatter. Bah Humbug!
You'll see folks telling how horrible or how great their rig drives, no matter the ratio or total length. No one can document the ratio thing.
If set up correctly, they all drive well.

Richard

It's called physics.

OK, any one can say a work. Can you detail what you said?

Richard

Sure, the formula for figuring out the dynamic forces on a wheeled vehicle includes the following components: center of gravity, weight of the vehicle, wheelbase of vehicle, height of components above ground level, acceleration or deceleration of the vehicle and a gravity constant.



While it seems like the size of the rear overhang won't make a difference in the handling of a vehicle, it does affect the forces the wheels experience because one component is the distance between the center of gravity and the axle ("d"). A large rear overhang moves the center of gravity toward the rear of a coach.

Agreed. And the forces are further complicated by a large sail area behind the axle for cross winds or wakes from passing trucks to act upon. Then it gets even more complicated when you tow something behind the motorhome, with down force on the tail of the chassis from tongue weight, also side forces when the towed vehicle or trailer pushes on the rear of the chassis at an angle during braking, as well as from any swaying action the trailer or towed vehicle experiences while towing.

The best plan for good handling is to have a very short rear overhang, particularly if the vehicle is used for towing.

I never understood why diesel busses and motorhomes don't place the engine in front of the rear axle, instead of behind it. The rear could be used for storage, which is much lighter than an engine. With the heavy diesel engine mid-ship in the chassis, it will have far better handling than a rear engine or front engine chassis.

Most high level sport and racing cars use a mid engine configuration, for that reason, be it just in front of the rear axle, or just behind the front axle. Engine hanging out either end is no good for handling.