miatainthe10s

Has anyone measured the cg for ford v8 miata. I know there are plenty of variables but just want round abouts data.

chpmnsws6

You'll be hard pressed to find that. If I grow a set, I'll do it with the L33. In class, we had a car on two 3 foot tall stands on the front end, and the back in on the ground (with scales on all 4 corners of course)

miatainthe10s

my car is completly apart and the suspension calc im useing to design the three link, cg height is imperative for getting anti squat and other figures close. i thought id throw it out there and ask. lol im sure not many people would understand how to do it let alone have a set of scales.

chpmnsws6

http://forum.miata.net/vb/showthread.php?t=364824

I'd run with Keiths figures of around 17". The engine is not going to throw it off much, if any.

miatainthe10s

thanks, but weight and where the weight is matters alot otherwise you could figure it out without scales.

chpmnsws6

Aren't you in a bind then? haha

chpmnsws6

What suspension setup will you be running?

If a 4 link, you have what, 50 different thrust angles to choose from, both pointing straight upward and all the way down....... I'm sure you can find something close the first few times you launch the car...... If you go nose up, you know your dialed in a little too aggressive

fourwhls

You can get an estimated CG from someone who has cornerwieghted a V8 car. Look for some cornerwieght number for each wheel. Measure the footprint and apply the loads accordingly.

mx5.7

I can't answer your question, but I have saved this website under my favorites for future reference. It is a good article and has a calculator and instructions on how to find the CGH.

miatainthe10s

im going to run a three link with a watts.

yeah im sure some have weighed there cars but haven't seen anyone with corner scaled there car. ill search the net.

chpmnsws6

How do you find the CG when using a flat plane measurement?

miatainthe10s

i was wondering also but didnt know if there was something i didnt know.

mx5.7

I didn't know you could do that.

fourwhls

Assume a rectangle with the measured corner weights applied at each corner. The Z axis dimension being an inch or two above the crank.

This is a very rough estimate, but should be relatively close.

miatainthe10s

ive seen figures anywhere from 17 to 23 posted by 4cyl. miata guys so either there not measuring right or every bit of weight placment matters. i would think the guys in the upwards of 20" should have a full roll cage, but our heavier motor should bring it back down some.

i know miata 1.0 weighed 2720 with me and a full tank.

the only reason im going down this path is theres only so much room to make mounts and three holes per mount is all i think ill have but doesnt leave a whole lot of adjustment if my initial numbers a scuwed.

chpmnsws6

Because I'm too lazy to make the entire car, I just made a rough of the links using three holes on each like you said you were able to have. That left around 20 options to choose from.... From putting the point about 4 inches in front of your wheels down to another unusable point about 10 feet in front of the car.

I miss doing those with the paper taped to the car

miatainthe10s

thanks ws6+