Poor man's scales?

[rstackjd]

Are scales additive? What I mean is, if you took 4 bathroom scales and put one under each tire, do they add up to the total vehicle weight? I saw saying to my son-in-law that I needed to find a place with a scale to weight the car and that was his suggestion.

Yes - No - ?

[SR Racing]

Nope, If stacked, each will show the total weight of that wheel. (plus one will being higher by the weigt of the upper scale on it.)

[rstackjd]

Nope, If stacked, each will show the total weight of that wheel. (plus one will being higher by the weigt of the upper scale on it.)

? No, not stacked - one scale under each corner of the car. Would the total of the four corners be the total weight of the car.

[billinstuart]

Absolutely. However, the accuracy of the scales is questionable. Weigh it twice with the scales under different wheels and average for a closer estimate.

[vreihen]

My late father tried to corner-balance an experimental aircraft using three bathroom scales at one point when I was a kid. The concept was sound, but the scales that he was using were not up to the weight being placed on them. Long story short, he wound up buying new scales for a few of our neighbors after breaking the ones that he borrowed from them.

If you plan to repeat this experiment, make sure that you don't use any digital bathroom scales. The reason is because every one that I've seen zeroes itself when you tap your foot on the weight pad to turn it on, and turns off after 15 seconds if someone doesn't step on the scale. Barring some elaborate ramps or rigging and four people to tap on the scales, roll the car onto the scales, and record the weight readings before the displays blank, these digital bathroom scales don't lend themselves to being used in this fashion.....

[hardingfv32-1]

One digital scale is fine. Just jack the corner up, set the scale and lower it down. The other three corners have to be on blocks the same height of the scale.

Brian

[rstackjd]

One digital scale is fine. Just jack the corner up, set the scale and lower it down. The other three corners have to be on blocks the same height of the scale.

Brian

Interesting - and then you rotate the scale to all four corners and add the totals? Very cool! Thanks

[SR Racing]

It will work fine with 4 $29 digital bathroom scales. Our first set-up for the F2000 was exactly that. I had to open them to modify the circuit board for timing issues similar to the one pointed out. Cheap bathroom scales will go to 300 or 350 lbs with no problem. They use a cantilevered strain gauge so they are only accurate to about 1% of full scale. But for corner weighting that is fine.

[Edward Schubert]

What should you look for......equal at all four corners?

[hardingfv32-1]

Zero roll or Z bar?

Brian

[SR Racing]

What should you look for......equal at all four corners?

Of primary interest is equal diagonally. IE. The total of the left front and right rears should equal the total of the right front and left rear. This is the most important on a 4 pick-up point car. If you have a zero roll and it is adjusted correctly and not binding, it is really more of a 3 pick-up point car and your diagonal corner weights will (should) be pretty close already with no adjustments required.

The total front/rear balance is going to be dictated by the design of the car and there isn't much you can do about it, with the exception of moving a battery, fire system etc. Your center of gravity is going to be near your butt usually and the closer you can get any movable weight to that point the better. Any fine tuning to balance the car (push/loose) will have to be done based upon feel at the track via tire pressures, alignment etc.

Of secondary concern is that the left front = the right front, and the rears the same. This is of much less importance in a formula road race car and of almost no importance in a zero roll car.

Now for the practicality of all this: If you have a NON-zero roll car you can adjust your rear coil overs to balance the car. (Make sure you have removed your z-bar connection and it helps to remove one end of your front shocks) To significantly change the front (left /right weights you have to bend the spring pack in the beam. (Usually not practical or neccessary)

If you have ZERO rull car, corner weighting is of almost no importance unless you have some bends, or binds, etc.)

In a zero roll vee, corner weighting is only really valuable to get the total weight of the car for legality purposes.

One of the nice things about a vee is that this work isn't normally needed. Check with a a guy at the track who has your same model (Adams?) andhe can give you the best alignment set-up for starting and then you can fine tune from there.

[Edward Schubert]

Jim, Thanks for all of the info. I have a zero roll car (Citation/Zink 18B). I am getting close to finishing my 1 year project in 2 years! Thanks again for all your help and advise over the phone. Ed

[rstackjd]

What should you look for......equal at all four corners?

In a zero roll vee, corner weighting is only really valuable to get the total weight of the car for legality purposes.

That's exactly why I want it. Yes, my car is a zero roll, so I've assumed that thre's not much to be done in terms of weight distribution, other-than the front - rear ditribution. But my main concern is making sure that I'm at the legal weight, or, if I over that I can look for savings somewhere (probably in the driver - gotta stay on that SlimFast!)

Thanks again. If I ever move to something with more sophisticated set-up requirements and options then I might look into "Real" scales, but it sounds like for Vee (and probably FST as well) the bathroom scales will do the job.

Thanks everyone!