I'm performing some load calculations, and need to know the CG height of a stock 94-01 Integra coupe. I estimated around 24 inches, but 4 inches in either direction could have a huge effect on the wheel loading under cornering, braking, etc. Anybody have a good idea of what the right answer is?

 

great questions.

I've tried googl'ing for the information before and didn't come up with much.

 

i would measure your stock ride height and then lower it the same all the way around not to throw off the weight distribution. also if you lower your car more in the front it will have more oversteer and if you lower it more in the rear you will have more understeer. you have to play around with the mods to suspension to make it perfect for your needs. that is what i had to do and i am still messing around with it sometimes. hope that helps

 

1. Hang it from a string.... from any two locations.

2. Imagine a line continuing straight down the string and through the car.

3. Where the two lines intersect is the center of gravity of the car.


Sorry. Since you can't actually hang the car from a string, I have no useful way to find the center of gravity of a car.

You could also measure the weight under each of the four tires. And from the wieght distrubution on each tire, you could determine the center of gravity in the horizontal plan. But that may be difficult to do (finding proper scales). And you still are left wondering about the center of gravity in the vertical plan. So, again.... useless.




Modified by PSU-TEG at 10:33 AM 5/29/2003

 

With individual scales, you measure weight on all 4 wheels.
Then tilt the car, say park sideways on a hill or put both right wheels up on ramps or something. As steep as you can...

Measure weight on individual wheels again. The amount of weight transfer from side-to-side and the tilt angle will give you the height of the cg.

 

integrate that bitch.
i forget the forumla, but i'm sure you can use some rough approximations of the dimensions of your car and use the center of gravity forumla from physics/calculus.

 

JimBlake, I agree this is the way to do it (it's the way race car engineers have done it for decades). In fact, you don't have to tilt it side-to-side, just putting the nose up by a substantial amount does the same job!

Not having appropriate scales, though, I'm sort of in a tough spot. I was hoping somebody on this board had already done it, but I guess that was wishful thinking...

BTW, I love PSU-TEG's "hang it from a string" suggestion.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VTechie &raquo;</TD></TR><TR><TD CLASS="quote">... In fact, you don't have to tilt it side-to-side, just putting the nose up by a substantial amount does the same job!</TD></TR></TABLE>
Side-to-side should give you a larger weight-difference to measure, for the same angle. If you put it on blocks instead of using a hillside, you get a larger angle for the same height blocks.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VTechie &raquo;</TD></TR><TR><TD CLASS="quote">BTW, I love PSU-TEG's "hang it from a string" suggestion.</TD></TR></TABLE>
Another way - jack up one side really, really high. Then measure the angle just before it falls over onto the door...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VTechie &raquo;</TD></TR><TR><TD CLASS="quote">BTW, I love PSU-TEG's "hang it from a string" suggestion.</TD></TR></TABLE>

I try.

Re-weighing it at an angle totally slipped my mind.

 

the CG is best described as the point at which u can balance an object on a pin point.