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Center of gravity?
Hasse - 22/9/05 at 02:24 PM

Hello,

Does anybody have an idea of where the center of gravity would normally end up on a "book build" with 1600 X-flow and Escort rear axle? Position of CG both in direction fron/rear and direction up/down of interest.

Thanks.


JAG - 22/9/05 at 02:38 PM

Front to rear = 50% of wheelbase - about 675mm behind front axle or ahead of the rear axle.

Vertically = 250-350mm

Laterally = 50% track width - about 700mm from inside face of one wheel towards centre of the vehicle.

It's very variable depending upon actual parts used, suspension ride height, driver only or driver and passenger, fuel tank contents etc....


kb58 - 22/9/05 at 03:08 PM

JAG, those figures sound reasonable, except for the 50% lateral placement. That seems unlikely with a driver offset to one side.


Bob C - 22/9/05 at 03:17 PM

you can 'tune' fore/aft by experimenting with battery location. Vertically, I tried to work it out for my BEC build by making a list of heavy lumps & their height (yes I was the heaviest lump....) and I got a height of 400mm (with 125mm ground clearance).
Has anybody tipped their car on its side to calculate it properly?
Bob


JAG - 23/9/05 at 08:29 AM

Your right and I thought I had covered it with;

quote:

It's very variable depending upon actual parts used, suspension ride height, driver only or driver and passenger



However consider the figures in my first post to be with the car empty.


Hasse - 23/9/05 at 10:37 AM

Thanks!

I was just trying to get an idea of roughly how large the weight transfer would be during hard braking, or how much weight there would still be on the rear axle.

/Hasse


britishtrident - 23/9/05 at 12:12 PM

The weight distribution is roughly 49% 51% rear.

CG height is roughly 60 to 120 mm above crank centreline depending on where you put the battery fuel tank and other heavy items.

Front wheels do roughly 60 to 67 % of the braking in a 1g stop. Size thebrakes to supply no more than 30% of the braking effort to avoid premature locking of the rears.