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jrh2009
jrh2009 New Reader
12/21/17 4:01 p.m.

Hey guys, I don't post here enough, but I know you guys are the right group to ask.

I am building a pro touring style vintage muscle car, and would like to find out the corner weights.

A quick call to a couple of local drag racing/circle track shops tell me they charge 150 just to roll the car on the scales and tell me the numbers.

That seems a little steep for 20 minutes of work. I know the scales cost 600-1200 bucks, but I can't bring myself to pay 150 bucks for that. 

So, having never looked to have it done before, is that the normal price?

It's not that I'm being cheap, it's just for that price, it makes more sense to buy my own scales. At least then I could weigh friends cars every now and then for extra beer money.

Or am I being completly unreasonable and 150 is the average rate?

 

NOHOME
NOHOME UltimaDork
12/21/17 4:32 p.m.

I had the exact same issue going on. Figured it would be easy to beg, borrow or rent scales. But my grapevine came up dry.

I bought two fat-boy scales that each weigh up to 440 lbs. This was like $80 Cnd  or maybe three-fiddy USD.

I built three platforms that raise three of the tires up to the scale height so that the car is level when being weighed.

 

I then put a board across the two scales and lower the car slowly on to the board in the middle of the two scales. Then I add the two numbers to get the corner weight. Repeat for each corner.

 

Pete

¯\_(ツ)_/¯
¯\_(ツ)_/¯ UltraDork
12/21/17 4:35 p.m.

Where are you located?  There might be a GRM member with access to a set of scales near you who could help you out.

freetors
freetors New Reader
12/21/17 5:18 p.m.

I have corner weight scales andputting the car on is the easy part. If I were to weigh a car with a wheelbase and track different than my own I would have to readjust my rolloff platforms to account for variations in the floor height. Leveling the scales could take an hour just by itself. That is if you care to know your weight distribution accurately. If you don't and you just want a total and to know the general distribution, you could throw it on and off in 20 minutes and be done with it. So you'll have to be honest with yourself about what you actually want out of it.

jrh2009
jrh2009 New Reader
12/21/17 5:21 p.m.

In reply to ¯\_(ツ)_/¯ :

I live just outside Columbus GA, 30 minutes from auburn AL. 

Unfortunately, there aren't many performance shops my way that deal with anything outside of 1/8th mile drag racing and dirt track stuff. 

But I'm all ears to solutions. I saw a write-up from a guy who did something similar to your method Nohome, I thought about that, (can't beat that price)  but didn't trust myself to replicate that accurately.

I see some different scales for sale around the interwebs for a (comparatively) reasonable $650, I'm really curious if it'd be worth while to pick up a set, find(or make) a level spot on my shop floor, and ask 75 bucks or so from local racers to weigh their cars. Seems like I'd only have to do a few to break even on the scales. 

Or is that a dumb idea?

Oh, and both shops I talked to told me they spend about 25 min or so weighing them. So I'm assuming they aren't concerned much with accuracy. Considering all of their customers either drag race or only make left turns, I assume they aren't chasing perfection.

alstevens
alstevens New Reader
12/21/17 6:20 p.m.

Near me there is a circle track that has a practice day during the week (Thursdays).   Cost was $25.  They've got a guy manning the scales the whole time.  A great deal even not using the track.  Call around if there are any close enough to you.

jrh2009
jrh2009 New Reader
12/21/17 6:42 p.m.

In reply to alstevens :

That's a great idea alstevens, there's a fairly big dirt track near my house. 

I'll call around and see if anyone there offers it.

Brian
Brian UltraDork
12/21/17 11:04 p.m.

There was an article several years ago on how to build/adapt your own corner scale setup.  Don't recall much more than that.  it was between 2007 and 2012.  it pops up on my facebook feed every year as a reminder. 

SVreX
SVreX MegaDork
12/22/17 6:57 a.m.

In reply to jrh2009 :

I've got a set of scales in Albany GA. I may be willing to loan...

SkinnyG
SkinnyG SuperDork
12/22/17 7:13 a.m.

I fab'd up a copy of RuggleScales, but could not get them consistently repeatable. Probably an operator error.

I now have some digital scales, if you're in the area.

GameboyRMH
GameboyRMH MegaDork
12/22/17 9:33 a.m.

$150 just to put the car on corner scales is insane. The trouble is that the amount of work involved in corner weighting can vary greatly depending on what kind of coilovers the car has...and how well you want it done. If the coilovers have independent height adjustment, it's much easier to move the spring seat, but that affects shock travel.

Ruggle scales are very sensitive to car positioning, unless they don't have a tilting panel for the tires to rest on, in which case they're a total crapshoot.

A more reliable way to get a cheap scale setup is to use 2 or 4 bathroom scales per corner:

https://grassrootsmotorsports.com/forum/grm/corner-balancing-on-the-cheap/62080/page1/

iceracer
iceracer UltimaDork
12/22/17 10:00 a.m.

In reply to alstevens :

Most dirt track scales are for total weight , not corners.     They have a minimum weight and are weighed after the race.

NEALSMO
NEALSMO UberDork
12/22/17 10:19 a.m.

Have you looked in to renting?  I had a bit of a friend hook-up and I think it was $100 for the weekend.  Renting would give you the capability to also adjust once setup.

jrh2009
jrh2009 New Reader
12/22/17 10:40 a.m.

In reply to NEALSMO :

I'd certainly be open to renting them, I just haven't found anyone local that offers them.

I am two hours away from Atlanta, and would probably have a much easier time finding a set to rent up there.

I really don't have the option to adjust coilovers, the car is a vintage Mopar, still on it's leaf spring/torsion bar suspension. I would like to know what the current weight distribution is so I can further improve handling.  I've already eliminated a ton of weight from the nose, and relocated the battery to the RR corner, but I'm at the point now where I should really learn the numbers so I know where to concentrate my efforts.

Thanks for confirming the 150 number is too high. That seemed crazy to me. Especially since I didn't get the impression those shops were chasing perfection.

SVreX, if I can't find anything close, I'll keep your offer in mind. That's really kind of you to offer to help a complete stranger 1.5 hrs away.

Thanks for the input guys.

Ovid_and_Flem
Ovid_and_Flem Dork
12/22/17 11:14 a.m.

In reply to jrh2009 :

I raced at East AlaBama many years ago. Do the Thomas boys still run it?

You're not gonna try reindexing front torsion bars, are you?  Just looking for what it is so can move ballast around?

I have a 911 with tb on both ends but have a fair amount of adjustabity with ride height adjustment.

STM317
STM317 Dork
12/22/17 11:16 a.m.

If you're just looking for a rough f/r weight balance you can probably go to any truck stop with scales and weigh your car for way less than your corner weight quote. They looked at me a little funny when I asked if I could do it, but they didn't have a problem with it. If I remember correctly it was <$20.

jrh2009
jrh2009 New Reader
12/22/17 11:52 a.m.

In reply to Ovid_and_Flem :

I honestly have no idea who's currently running that track, even though I live 10 minutes away. It's still massively popular, and always has a full house. The owners seem to be doing a great job from a business perspective.  Probably why all the local speed shops cater to them.

As for indexing, I honestly hadn't considered it. I have made a bunch of suspension improvements, but that hadn't crossed my mind. I honestly don't know much on the subject.

I am still running the original .84 inch bars, where as the rest of the pro touring guys have stepped up to bigger 1.0 or bigger bars by now.  They maybe coming out in a future upgrade, but I'm hesitant to touch them now, as I've got initial turn in to be neutral with minimal understeer, and a good ride quality on the street. I've been building to the "under spring, over sway" philosophy so far.

I'm really just looking for the corner weights to rearrange/shed ballast for now. There are still plenty of more places it can lose weight, I'd just like to see the numbers before I keep charging ahead blindly.

Also, 911s are awesome. I regret not picking one up before the market exploded.

frenchyd
frenchyd Dork
12/22/17 12:18 p.m.

In reply to SkinnyG :

I bought a set of ruggles  scales and  used them for everything, still have them. The trick is finding the level spot because every time I’ve tried to make a spot level it goes blooey  

For information Ruggles scales are 4 bathroom scales that use the lever principle to handle a car’s weight.  

I baseline them by putting a fixed weight (  an engine block  ) on each one in exactly the same spot.  Then I carefully place the tire on each pad. In exactly the same spot. 

mlwebb
mlwebb New Reader
12/22/17 12:50 p.m.

I have been wanting to weigh my car too, good thread. A little googling for bariatic scale found the My Weigh XL with a 700 lb capacity for <$90 (surprised my local Walmart doesn't carry these). That should do my car with a 100 lb headroom. One scale and three 2" pads.  

jrh2009
jrh2009 New Reader
12/22/17 1:12 p.m.

I did stumble across this (comparatively) simple DIY approach, which seems simple. 

http://forums.pelicanparts.com/porsche-911-technical-forum/629644-home-made-corner-scales.html

But probably time consuming. Especially for guys without lifts. Also, it seems like the weight wouldn't be settled normally if you used a floor jack to place the car on the scales??

Ovid_and_Flem
Ovid_and_Flem Dork
12/22/17 1:39 p.m.

In reply to jrh2009 :

Since the season is essentially over for the next few months you might just stop by the shop at EAS (I guess they're still building cars in shop towards outside of turn 1) and explain to them you  are just looking to put it on corner scales to see what weights are.  They may do it cheap if you just need to roll car on and off. 

 

Weigh it both.with you in as well as not.

SVreX
SVreX MegaDork
12/22/17 1:46 p.m.
jrh2009 said:

I did stumble across this (comparatively) simple DIY approach, which seems simple. 

http://forums.pelicanparts.com/porsche-911-technical-forum/629644-home-made-corner-scales.html

But probably time consuming. Especially for guys without lifts. Also, it seems like the weight wouldn't be settled normally if you used a floor jack to place the car on the scales??

Wow. That's a complicated way to do it. 

A piece of plywood laying across all 4 scales would do fine.   Blocks the same height as the scales + plywood set in front of the scales would enable rolling the car on and off the scales to settle the suspension. No lift necessary, no welder, and no complex setup. 

NOHOME
NOHOME UltimaDork
12/22/17 5:30 p.m.

If you just want to do a F/R weight distribution, get two floor jacks and a beam that you can pass under the car. Lift in the middle and keep going front or back till you find a balance point; congrats, you just made a car teeter-toter

 

Measure the length of the car and the fulcrum point on the teeter-totter. Do the % math, Make a mark on the pinch-weld and use it to gauge if any changes are shifting weight backwards.

 

Pete

Wally
Wally MegaDork
12/22/17 8:36 p.m.
Jrh2009 wrote:
Oh, and both shops I talked to told me they spend about 25 min or so weighing them. So I'm assuming they aren't concerned much with accuracy. Considering all of their customers either drag race or only make left turns, I assume they aren't chasing perfection.

Seeing as the only people you could find that own scales drag race or make left turns they may be more interested in scaling a car correctly than you think.  I would guess the $150 price is more an indication that they aren’t too interested in doing it for other people.   I’ve been in that spot before and while I could set our cars up pretty quickly people coming in off the street never seemed to know how to get things set up how they wanted and expected us to make things right on their car. 

jrh2009
jrh2009 New Reader
12/22/17 9:41 p.m.

In reply to Wally :

Yes, I suppose that could be the "make it worth my time" price. 

But I'm not interested in paying the "make it worth my time" price either.

I'd honestly rather buy my own scales and sell them when I'm done instead of paying the make it worth it price. The depreciation in value can't be that much more than the 150 I'd pay the other shop, considering the value I'd get out of them.

150 bucks just to roll the car onto the scales and tell me the numbers (which is really all I'm after) is a little much. 

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