Cascade Crew

blue89 · Posted: Thu May 17, 2007 11:54 am Post subject: Car Scales

Does anyone have some corner weight scales? I think I need some. Might help.

Has anyone tried to use bathroom scales? If one will do 350lbs, then two will do 700. I could do the rear weight with that! Just lift up the car, put both on the ground and use a hunk of plywood or 2x12 to help dist the load.

Anyone seen some DIY or cheap corner scales?

Dewey316 · Posted: Thu May 17, 2007 12:25 pm Post subject:

Use bathroom scales, them make some arms for it, and just know what your lever ratio is, that will extand the use.

BigDaddyVu · Posted: Thu May 17, 2007 12:35 pm Post subject:

go to the wsp they have portable wheel scales. gawd i know they do lol.

blue89 · Posted: Thu May 17, 2007 12:51 pm Post subject:

Thats a good idea about the lever arm. Hmm...

Pivot------Tire------Scale

Right?

F=M*D

So

M1*D1=M2*D2

M1*D1/D2=M2

Just got to make it so the car doesn't have to be lifted all that much. Sweet.

Dewey316 · Posted: Thu May 17, 2007 1:01 pm Post subject:

you got it, you will might want to put pivots on the pad for the tires, just to make sure you don't have any funny side loading forces etc. Just like you would have on an alignment rack.

blue89 · Posted: Thu May 17, 2007 1:39 pm Post subject:

I'm gonna have to try it out when I get home. Lol. I'm gonna be busy tonight.

Think it would be better to put the scale to the side or to the rear? I'm thinking I could make this so I can drive up to it instead of lifting the car up and then putting it down. Then I could make a dummy ramp for the other side. Now I just need some baddass hinges. Or I'll use angle iron.

Dewey316 · Posted: Thu May 17, 2007 2:20 pm Post subject:

I think you would be fine making a ramp. Just make sure the pad you drive onto is level. You will also need to have ramps for the other wheels, and make sure everything is level. If anything is out of level, you will have jacking effects, and your corner-weighting will be skewed.

blue89 · Posted: Fri May 18, 2007 8:12 am Post subject:

My idea for keeping everthing level will be to lift the front or rear, and then picking up the other side with one jack dead in the middle. Since the chassis will only have 3 points lifting it, it will naturally level itself. Doing it this way should also alleviate the need to disconnect the sway bars?

Dewey316 · Posted: Fri May 18, 2007 8:21 am Post subject:

You may want to corner weight it with the sway bars off, then with them on. That way you make sure you are neutral and not preloading any of the sway bars.

You can also use those scales to figure out your CG, just make a solid rod for the shock, so that you don't have any spring compression. Then you lilft the front a certain amount, and calculate the weight transfer, you can use that to find the CG. Very Happy

(I really need to get those longacre corner scales.)

blue89 · Posted: Fri May 18, 2007 10:02 am Post subject:

Mmmm... adjustable sway bar end links. I might have to make some of them too. Lol. Heck, if I go through all the trouble, I might as well load them to make them weight jacks!

This is the problem. Once I start a project, it might as well be done right. I went from "Corner Scale" to "Weight Jacking with adjustable sway bar end links" all in one thread.....

Dewey316 · Posted: Fri May 18, 2007 10:18 am Post subject:

I don't know that I would want to weight jack with end links. Just get real weight jacks like I did. Wink

blue89 · Posted: Fri May 18, 2007 10:26 am Post subject:

AutoX rules generally prohibit the use of weight jacks.

In effect though, the weight jack is doing just that right? Its changing the ride height of just one side which pushes on the sway bar. Other wise there would be no way to transfer the weight, which is what a sway bar does.

91RSVert · Posted: Fri May 18, 2007 10:50 am Post subject:

Dewey316 · Posted: Fri May 18, 2007 11:35 am Post subject:

You trasfer weight through the jacking effect. Idealy you balace things by adjusting the ride heigh, then attach your sway bars, and adjust the end links so there is zero effect by them at the resting position.

Remeber, you are transfering weight diagonaly with weight jacks, from the R/F to L/R and L/F to R/R. That is how you properly corner-weight a car.

blue89 · Posted: Fri May 18, 2007 11:43 am Post subject:

K. We're on the same page now. Thanks for the reminder. Been a while since I've thought about weight jacks. So it sounds like I need to get my scales built!