Weighing a car with a bathroom scale.

[godzillarb]

I realize that most people just take their cars to the dump or whatever to get a vehicle weight. This is fine for most, but not me. I want to know the corner weights and weight distribution. I also don't want to pay someone to use their race scales. Anyways, I did some searching around on google and this is what I found:

http://i231.photobucket.com/albums/ee178/jslade_usa/Weight1.jpg

Might look stupid but should work. The key is not killing the bathroom scale with your over weight car. To do this you use a 4 foot board that is marked every foot. The car should sit on the 3' mark, thus putting 75% of the weight on the ground and only 25% on the scale. Also, to ensure proper readings the car should be sitting as level as possible, basically the other 3 wheels should be at the same height as the one you're weighing.

Take the reading on the scale and divide by .25, and BAM! Corner weight.

I haven't tried this, but will be giving it a shot when I get home from VA. I got my Jetta weighed professionally a couple months ago (only because it was free) so I'll be able to see just how accurate this method is.

If someone else posted this idea before, my apologies. Every time I tried to use the search button it gave me an error.

[racepar1]

That is not a reliable way to get any sort of weight measurements from the car. All the tires have to be in the EXACT same position on the boards and the boards have to be the EXACT same length and the pivot point (the angle iron used in the pics) have to be in the EXACT same position. Also the car is not level, which is VERY important for accurate corner weights. There is no reliable way to half ass corner weighting. You either need a COMPLETELY level floor and 4 heavy duty scales or a set-up platform and 4 heavy duty scales. Search for an affordable solution on websites like coleman racing's or google "longacre". Longacre makes all kinds of racecar set-up tools.

[jspaeth]

I would agree.........this is a cool idea, but in terms of practicality, there is not way you are going to be able to do it precisely enough for it to even matter, unless your corner weight are outrageously terrible.

[luftrofl]

Also, to ensure proper readings the car should be sitting as level as possible, basically the other 3 wheels should be at the same height as the one you're weighing.

That strikes me as something that is much easier said than done. If you're off by just a small amount, your measurements will be basically worthless.

[derk]

.... that looks soooooo mickey mouse.

[godzillarb]

why dont you just pay to get it properly corner balanced.... jesus.

The whole idea was to be able to measure, adjust weight, remeasure, and so on. I really doubt if the guys at a race shop would be cool with me camping out for a day and tinkering with the weight balance of my car.

The guy in the picture really half-assed it, no question.

Oh well, it might be a hopeless endeavor but just out of curiosity I'll weigh my Jetta using a similar method and cross check it with my print out from the professional scales.

[S14DB]

Would have to think to pay someone to corner weight would be cheaper than 4 scales and all that other crap.

[racepar1]

The whole idea was to be able to measure, adjust weight, remeasure, and so on.

To be able to do this ^^^ with a set-up like that would be almost impossible. You simply cannot trust any information you get from that set-up. If you really wanna corner weight yourself you absolutely HAVE TO spend some money on a proper set of scales. There ARE budget options here, you just need to do some research.

[racepar1]

Would have to think to pay someone to corner weight would be cheaper than 4 scales and all that other crap.

That all depends on how often you want to corner weight. I wouldn't mind corner weighting my car every 2 to 3 track events as I am constantly changing the set up here and there.

[godzillarb]

There ARE budget options here, you just need to do some research.

Yep yep. I did, cheapest set of pads I found were $750ish. Maybe I'll be able to find a used set.

Looks like I'll do some calling around to find out where I can get my car on a set of real scaled when I get home. I'm doing a bunch of weight relocation so I might as well put it on the right side.

Thanks for the advice though :)

[gotta240]

The thing you posted has been done for a long time by budget racers. The one you posted is very ghetto though. A better and more accurate system can be made from metal. Instead of setting the car on a POINT you must make a mini ramp with two pieces of metal that HOLD the wheel exactly at one point.


such as



Pivot______I TIRE_I_______________Scale
.
Dont let these people discourage you. Most of them have probably never corner balanced their own car or know how expensive it gets when changing your suspension set-up and needing a new balance EVERY track day. Although the set-up i mentioned above is not accurate to the pound, it is 13939399239239 percent better than doing NOTHING...like most people on this site do.

[cdlong]

Take the reading on the scale and divide by .25

or, you know, multiply by 4. a little easier to do in your head.

conceptually it works just fine. in practice, it's a little harder as stated, but it still gives you a very good idea. especially if you're changing stuff every weekend and don't want to pay each time you change something.

depending on how much your car weighs, which corner, and the range of the scale, you could adjust it for more accuracy. i.e., if the corner in question weighs 600 lbs and the scale goes up to 300lbs, you could put the tire in the middle.

[Sil-Abc]

take an engineering statistics class ull learn that method is way off. the weight distribution is all bad, wood will bend, pivot points will always be different. overall, bad idea but at least its an idea. honestly, just save up and get it done right. my 2 pennies

[ALEXTHESUS*PECT]

not reliable enough to trust.

[S14DB]

Why not get some 1,000 lbs scales? Prolly be as much as 4 bathroom scales and all the parts of that rig.

http://www2.northerntool.com/product-1/22929.htm
http://www.1800scales.com/High-Capacity-Platform-1000.html

[racepar1]

Why not get some 1,000 lbs scales? Prolly be as much as 4 bathroom scales and all the parts of that rig.

http://www2.northerntool.com/product-1/22929.htm
http://www.1800scales.com/High-Capacity-Platform-1000.html

There is your answer! ^^^

[gotta240]

Because that costs 800 to 1000 bucks for 4. The way i described in my post cost under 200 and is fairly accurate.

[racepar1]

Because that costs 800 to 1000 bucks for 4. The way i described in my post cost under 200 and is fairly accurate.

If "fairly accurate" is good enough for you then go for it! That is simply not good enough to satisfy me. I want exactly accurate and will settle for nothing less. If I can get something that is exactly accurate for under $1200 I would consider that a bargain.

[jholman05]

Why do you need 4?, just get some make some blocks the same height as one of those $200 scales and weigh each corner individually, mark it down and adjust accordingly.

[Wabash9000]

why not just put 4 scales under all four tires. 16 scales...

idk seems all very getto but very 240.

[babowc]

^lol.
funny!

how much does a bathroom scale cost??.. 30?

[gotta240]

OH PAAAAALLLLLEEEEEEEEEZZZZZEEE. Unless your car is a 100,000k race car and you are a PRO driver, you will not notice a 20lb difference in a scale. I'm not even saying this to insult you or to be a dick, but honesltly, i've seen your car and you would be better off spending that 1000 bucks extra in upgrades and not worrying about the .5 percent difference in corner weights due to a "NOT PERFECT" scale.

Now honestly, lets quick the bullshitting. How many times did you corner balance your car last year?


If "fairly accurate" is good enough for you then go for it! That is simply not good enough to satisfy me. I want exactly accurate and will settle for nothing less. If I can get something that is exactly accurate for under $1200 I would consider that a bargain.

[S14DB]

Damn, I'm not a race car driver. Time to buy some rota's and sleeve coil overs...

Just cause your not a pro driver doesn't mean you have to half ass things.

[g-via]

Why not get some 1,000 lbs scales? Prolly be as much as 4 bathroom scales and all the parts of that rig.

http://www2.northerntool.com/product-1/22929.htm
http://www.1800scales.com/High-Capacity-Platform-1000.html


1000 lb bathroom scales?!

ahh....you'd only need that in the states! LOL jk, jk, i know most of you guys are in the US....eh....

[racepar1]

OH PAAAAALLLLLEEEEEEEEEZZZZZEEE. Unless your car is a 100,000k race car and you are a PRO driver, you will not notice a 20lb difference in a scale. I'm not even saying this to insult you or to be a dick, but honesltly, i've seen your car and you would be better off spending that 1000 bucks extra in upgrades and not worrying about the .5 percent difference in corner weights due to a "NOT PERFECT" scale.

Now honestly, lets quick the bullshitting. How many times did you corner balance your car last year?

I've done it twice since november and it could use another shot as I wanna lower it some more and change my alignment settings just a bit. Don't insult my car. If you really wanna talk shit let's take it to the track. Just because it looks ugly doesn't mean that it isn't well modified and maintained. I am absolutely positive that if we put our cars up on racks right next to eachother mine would be cleaner and better maintained.

[crzycav86]

This method will work. It might be 10% off(just a guess), but you can make it work.

First, like has been mentioned, you need to raise the other 3 wheels by the same amount.

Second, you need to subtract half the weight of the wood, and subtract the weight of the metal bracket sitting on the scale.

Third, instead of assuming that you've got the wheel 75% away from the scale, find out exactly how far it is bymeasuring where the middle of the wheel sits(from one end), and dividing it by the distance between the two metal mounts.

Fourth, if you want an accurate corner-weighting, you need to load up the driver's seat with weights. (equal to your weight)

Fifth, If the car weighs 3000 lbs, approximately a 1/4 is on each wheel, that's 750 lbs. If your scale reads up to 250, you can locate the wheel 66% away from the scale without maxing it out. The scale will read more accurately the closer you can get the wheel to it. On the same token, a longer piece of wood will help you measure more accurately. Just make sure it doesn't break.

Hope that helps.

[cdlong]

take an engineering statistics class ull learn that method is way off. the weight distribution is all bad, wood will bend, pivot points will always be different. overall, bad idea but at least its an idea. honestly, just save up and get it done right. my 2 pennies

i took an engineering statics class, and did the calculations, the method is fine. wood will bend, but that doesn't matter, it is statics after all. pivots points will not always be different if you set it up properly. it's aready been stated that the picture is a ghetto setup and can easily be improved upon to make an accurate system. actual weights don't really matter anyway, only the relative weights.

stop giving the guy shit for a sound idea.

[McRussellPants]

Doesnt work.

Car isn't Level.

Motion Ratio would be wrong every time.

Gotta 240 Sucks at cars.

Weird Cross weight is totally noticeable.

Borrow someones scales or pay 100$ to get it done at a raceshop.

[crzycav86]

take an engineering statistics class ull learn that method is way off. the weight distribution is all bad, wood will bend, pivot points will always be different. overall, bad idea but at least its an idea. honestly, just save up and get it done right. my 2 pennies

I don't know which engineering school you went to, but I learned how this works in STATICS.

The rest of what you said doesn't explain anything. Care to elaborate on what you learned in statistics?

[kognition]

I think that the issue you are having is paying someone who has invested the odd thousand bucks for legit scales. If you want to legitimately weight and scale your car (corner balancing), you must use the right equipment. Weighing your car really is a waste of time unless you are corner balancing it at the same time.
At the end of the day, you will never know if the bathroom scale is being truthful. My wife says hers always lies anyway. :)
Corner balancing is usually anywhere from 50 to 100 bucks, depending on the shop.
You will be amazed at how well a properly corner balanced car will handle.

[92coupe]

Yeah, man go for it. Just do each wheel EXACTLY as you did the one before...if the actual weight is off don't worry about it since you are just doing (as it's called in my field) weight and balance. It'll work for that purpose. But when you want the "Weight of your car" you could do what I do. Go down to the friendly gas station with the digital CAT scales and weigh it there.

BTW...500hp. Trans Am, with 2 12" speakers in a box, a big tool bag and me in it 4048lb. How's that for a fiberglass sportscar! http://i36.photobucket.com/albums/e39/clintman12345/Smilies/smileys12.gif

[crzycav86]

i took an engineering statics class, and did the calculations, the method is fine. wood will bend, but that doesn't matter, it is statics after all. pivots points will not always be different if you set it up properly. it's aready been stated that the picture is a ghetto setup and can easily be improved upon to make an accurate system. actual weights don't really matter anyway, only the relative weights.

stop giving the guy shit for a sound idea.

Pivot points don't have to be exactly the same because you calculate it regardless. They don't all have to be 75% or whatever from the scale.

The only crucial thing is getting the heights level. If the wood bends by a significant amount, then it will be hard.

[gotta240]

Doesnt work.

Car isn't Level.

Motion Ratio would be wrong every time.

Gotta 240 Sucks at cars.

Weird Cross weight is totally noticeable.

Borrow someones scales or pay 100$ to get it done at a raceshop.

I suck at cars because i don't believe in paying 1200 bucks for something that cost me a couple hundred? My setup isn't a fucking piece of wood, but uses the same CONCEPT. It IS accurate within reason because it uses METAL and EXACT POINTS(to the 1/8 of an inch) unlike the thread starters technique. You faggots flame shit because it cost less and you have never seen it before.
I don't claim to be a suspension expert or pro racer, however, this method was taken from old school racers who have had more experience than 90 percent (that 10 percent being Kognition..lol) of this hard parking websites drivers and has been proven to work. Also, like stated earlier, no one on zilvia will notice a 10lb difference corner to corner in their shitty ass 240s.

[gotta240]

I've done it twice since november and it could use another shot as I wanna lower it some more and change my alignment settings just a bit. Don't insult my car. If you really wanna talk shit let's take it to the track. Just because it looks ugly doesn't mean that it isn't well modified and maintained. I am absolutely positive that if we put our cars up on racks right next to eachother mine would be cleaner and better maintained.


Dont be such a fucking pussy. I didn't "talk shit" or "isult your car". I simply stated facts. Your car could benefit much more from 1200 bucks of parts than being dead on with corner weights.
Stop acting like i insulted your mom or girfriend dumbass.

[crzycav86]

nah...............

[errolorion]

ive done that
it works

[92coupe]

Just do it man!
The alternative (at the same price) is to find someone to let you do it for free, so give it a shot, see how close you can get.

This is the internet...there will be people who have tons of money and there will be broke ass folks like me who have to find their own way. If you work it down to a good repeatable science then you are good. You're still gonna get flamed by the other folks with plenty of cash to pay to have it all done, but you *could* end up with a cheaper viable alternative at your home and do it anytime you want. At 3A.M. in the pouring rain if you want to.

AAAND if it never works out, whoopity shit, at least you are trying and you're not off spraypainting something. http://i36.photobucket.com/albums/e39/clintman12345/Smilies/2166_shocked.gif

[godzillarb]

This thread turned into a bit of a pissing contest.

Like gotta240 said, it was the concept. If I try this, it'll probably with a metal jig that I'll weld up so everything is exactly the same every time. I also found a highly accurate 400lb digital scale for like $25.

I'm pretty confident that I'll be able to get the weights correct within a small degree of error, maybe 5-10% by using a laser leveler and by not using such a crude scale and jig to hold the car's tire.

The race scales would be sweet as hell, but I'd be better off spending the $1k on a roll cage and fuel cell at this point.

We'll see though, seems like a fun afternoon experiment.

[racepar1]

Dont be such a fucking pussy. I didn't "talk shit" or "isult your car". I simply stated facts. Your car could benefit much more from 1200 bucks of parts than being dead on with corner weights.
Stop acting like i insulted your mom or girfriend dumbass.

Did I go out and buy a scale set-up? NO! Am I planning on buying a scale set-up anytime soon? NO! But if you wanna have your own scale set do not half ass it! I won't half ass it when I get around to buying a scale set. Set-up is just as important as mods, if not more so!

[gotta240]

Point proven. You haven't purchased a scale set-up nor have you tried to build your own. Why even post or get defensive if you have done NEITHER of the two with no proof or evidence AGAINST what is being said.
I admit, many of your posts are informative and beneficial, but the last few have been quite the opposite. Lets not forget, many (99.9999%) of 240 owners are just going for BETTER, not perfection. This scale IDEA is BETTER, but not perfect. Lets not flame people who are trying to better their cars and track times on a budget.

[g-via]

this can be done easily with a static analysis of the situation....i have no time, but I'll do my car after finals

[dirtdiggler666]

lucky me i got rich drag race buddys with legit scales

and im sorry but this seems like a bad idea

but this is zilvia so it seems like a good idea well to some:ughd: just lowball and you will be good

[cdlong]

Yeah, man go for it. Just do each wheel EXACTLY as you did the one before...if the actual weight is off don't worry about it since you are just doing (as it's called in my field) weight and balance. It'll work for that purpose.

oh god, doing it one at a time would be tedious beyond belief. when you change one, the others change too. you'd have to go around the car like 5 times to get it right. just get 4 scales and pivots.

Pivot points don't have to be exactly the same because you calculate it regardless. They don't all have to be 75% or whatever from the scale.

The only crucial thing is getting the heights level. If the wood bends by a significant amount, then it will be hard.

with 4 scales, it wouldn't matter how much the wood bends, as long as they all bend the same amount. also, it would be much easier if the pivots all matched exactly because you wouldn't have to convert anything. since it's all percentages, multiplying by 4 on each would give you the same result.

as kognition said, the actual weight is pretty worthless. like a dyno, it's just for tuning, the number output at the end is just for bragging rights.



i'd have to look at my sheet again, but i don't think i had a corner over 800lbs when i weighed my s14 and it's pretty much stock weight wise. you could put the tire in the middle on those 400lb scales for a decent improvement in accuracy.

[WatchingEye]

This idea is quite working one and also shows your search on weighing car. But that is not enough to have accurate and constant measurements. It is also a bit harmful for your scale . The platter of your bathroom scale must be made with some metal if it is plastic one then easily will be broken by the car weight. I think portable truck scales (http://myscalestore.wordpress.com/) are the best in this regard. You may weigh your vehicle easily, safely and accurately.

[piein3ar]

Divide by 4 and visually inspect the rest?

[Croustibat]

This idea is quite working one and also shows your search on weighing car. But that is not enough to have accurate and constant measurements. It is also a bit harmful for your scale . The platter of your bathroom scale must be made with some metal if it is plastic one then easily will be broken by the car weight. I portable truck scales are the best in this regard. You may weigh your vehicle easily, safely and accurately.

First post, resurrects a 6 year old thead to add ... nothing.

Nice start.

[WatchingEye]

It was very surprising for me that it is an interesting and very effective thread then why not in use???:duh:

[racepar1]

This idea is quite working one and also shows your search on weighing car. But that is not enough to have accurate and constant measurements. It is also a bit harmful for your scale . The platter of your bathroom scale must be made with some metal if it is plastic one then easily will be broken by the car weight. I portable truck scales are the best in this regard. You may weigh your vehicle easily, safely and accurately.

It was very surprising for me that it is an interesting and very effective thread then why not in use???:duh:

WTF???? I see words, but deciphering the meaning behind them seems to require a decoder ring or something...

:tweak:

Also, go you for bumping a 6 year old thread with a dumbass idea. You can buy a proper setup to corner weight the car with bathroom scales rather than going all redneck with 2x4's...

:goyou:

[sidewaysil80]

What happened to this site?




No, seriously...what happened here?