Whats the proper way to weight a car..?
I am askng for your thought on this: let me give you the low down first, the car normal runs at one local track (race there all year-no issues there)and last race we weight in it was 3405 (has to be 3400) so i put a extra 25 weight in the car just in case, went to another local track, first time this year, my son came in 3rd with the same car (no changes were made- car or driver)but when they tried to weight him they said he was 55pds light, here is the problem:

the use 2x6 boards between the scales (front to back) which means you drive up a ramp then across the board to set the car on the scales (which are under the board) keep in mind the scales are elevated between plates so the scales still up just a inch or so,  one, they couldnt get the car on stright for one thing but i think by using the boards it casue the scale to off set and not read correctly.
Now if i am wrong then i accept that but i dont think so casue i know what the car weights and it hasnt changed all year, i do think this way of scalling the cars is wrong,
comments, Thanks  

1). If the car wasn't sitting on the scales properly (e.g. centered), you could easily get an innacurate reading.  

2). did you have the same amount of gas in the car?  Gas is heavy stuff and could easily contibute to a 55 lb diff.  

Gas could be a problem, but if the scaled aren't level, you will not be able to get an accurate read.  

Yes fuel level can alter your cars weight a bit, but what we have seen when going from track to track is that the scales do not read the same.  It all depends n how well they are taken care of ( we all know that they are all spotless and never touch anything dirty), that they have never gotten wet, ( we all know it never rains on race nights) and have never been bounced hard or jammed when rolling on or off the scales.  That is why whenever we go to a different track, we always ask to scale at the beginning of the night to make sure.  It is the racers responsibility to make sure his equipment is legal.  Hope this helps.  

How bout your tire pressures and all your fluids,were they all the same?I do know if you change the tire pressures even just a pound in or out on any of the tires you change all your settings!later, choochoo  

Assuming it's not fuel or other obvious weight reductions;

I agree with one of the other posts that track scales are quite abused and they can, and usually are, out of calibration.

Many of the racing scale products are actually very poorly constructed and can cause large errors if the tire is not centered on each pad.  The strain guages used in cheap scales will not be properly matched to the flexure element in the balance, this means that  errors can be caused by changes in temperature.  For a 55lb error, abuse or incorrect calibration is more likely.  

The boards won't affect the total weight reading as long as they have been tared out and are not touching anything but the scales. (check the scales before you roll onto them to see if they read 0)

Tire pressure has no effect on total weight.

Our team noticed a consistent offset between our scales and the track's scales - we noted how much it was and adjusted accordingly.