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Discussion Starter · #1 ·
Does any one out there in the wide world of opels know what the weight distorbution is on a 70 gt. I am running a 2.4 fi motor 5 spd getrag. battery in the back. Iam trying to get my custom brakes figured out and I think if I can find out the weight bias I can get them dialed in .
Thanks
 

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Someone might be able to tell you the weight distribution as delivered from the factory, but as soon as you start to change and move stuff around, the best you are going to get is a SWAG... Scientific Wild A$$ Guess. I don't think there is any way around using a set of scales.
 

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Stock GT's are around 53%-55% front weight, but moving the battery to the back changes this almost 2%....on my '73 Ascona it changes from 52/48 stock to 50.2/49.8 just by moving the battery!

Of course throw the driver into the car and everything changes. I saw from your other post that you're 6'-6" and 320 lbs! That will make a huge difference, not only from front to rear but also left to right.

Full tank of gas? That changes things too...

I have some racing scales that will accurately weigh all 4-corners and give front/rear, left/right, and diagonal weights down to 1 pound.

If someone from New England want to get accurate weights of a bone-stock GT, let me know and we can make an appointment to throw your car on my scales, then post the results here on opelgt.com as an FAQ. I keep my scales at the family business in Avon, Connecticut. Directions to the shop are at www.legeregroup.com .

Bob
 

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70's Opeler, back 4 more!
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Here is another idea for finding out the weight distribution, at least front to back.

Find a place that sells rock or gravel by the pound. They will have scales for measuring the weight of the trucks. A truck stop might be another place.

Check with the guys to see if they will weigh you front, full vehicle, and back, as you drive through. You can do this with an empty car and sitting in it.

If the place you find is like most places, they'll enjoy just the idea with no fee.
 

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Opeler
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Here's one idea...

I bought 2 $9 scales from Bed Bath & Beyond, and I'm planning on taking them beyond the bed and the bath all the way the the garage. I figure the scales are only accurate within the 100-200lb range, so a 2400lb car should be around 600 lb at each corner, so I'm going to try building a lever with a 4-1 mechanical advantage, calibrate it using weights of known amount, and then put the car on the bathroom scales. For instance, if the scale reads 164lbs front right, 168lbs front left, that would actually be something like 656/672. I realize that the scale probably is only accurate to about a couple pounds, and then I'm multiplying that by 4, so in all this set up will really only give you numbers +- 10 pounds. Ain't exactly a measurement the McLaren F1 team would design with, but it'll work for me knowing if I'm in the right weight distribution ball park (I'm relocating a lot of stuff for a long in coming V6 conversion), and a lot cheaper than legit racing scales by a long shot. Ain't got it built yet though. I'll let you know how that works out.

If only I could afford Rallybob's shop ;-)
 

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Sporqster said:
If only I could afford Rallybob's shop ;-)
I wish I could afford that sized shop too. I keep telling my old man to get rid of all that damn woodworking stuff so I can get some cars inside, oddly enough he usually just rolls his eyes and walks away when I suggest that....

But since I'm one of three machinery maintenance guys, and the only welder/fabricator in the building, and I use my own equipment to weld and repair the machinery, I had a legitimate argument to have a corner to work on my car projects...just can't keep any cars indoors. My work area is only about a 15 x 30 space, but it's better than being outside. The alternative, I told my old man, was I would leave my welding equipment at home, and when a repair for the shop had to be made, I'd do it after hours at my house at a cost of $100 per hour.

Bob
 

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70's Opeler, back 4 more!
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Just buy four scales, stack them under the wheel and then add up the amounts of all four for the total weight.

Sorry! couldn't resist. :D

Send in pictures of what you are able to work out. It would be interesting to see how you position your lever, fulcrum, and scale to get your final weight.
 

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Bariatric Scale for Corner Weights

I bought a bariatric scale with a 700 lb. capacity, and an oversized platform (XL700 ~$86). I made a small additional platform out of OSB with a cut-out so the tire wouldn't set down on the display. Plus, it was a talking scale so I could start the tare measurement on the scale, run around to the jack, wait for the scale to tell me it was ready, lower the jack, and then have the scale tell me the corner weight even if the tire was covering the point where the display was. On my 1970 GT with:

Original battery removed, replaced with 25 lb Miata battery in package shelf
No Spare tire, no jack, no shelf for spare tire
1/2 tank of gas
150 lb. simulated driver (sack scratch grain plus 4x 25 weight plates)

LF 625 RF 584 53.3%
LR 533 RR 525 46.7%

Total 2267
 

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Über Genius
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I bought a bariatric scale with a 700 lb. capacity, and an oversized platform (XL700 ~$86). I made a small additional platform out of OSB with a cut-out so the tire wouldn't set down on the display. Plus, it was a talking scale so I could start the tare measurement on the scale, run around to the jack, wait for the scale to tell me it was ready, lower the jack, and then have the scale tell me the corner weight even if the tire was covering the point where the display was. On my 1970 GT with:

Original battery removed, replaced with 25 lb Miata battery in package shelf
No Spare tire, no jack, no shelf for spare tire
1/2 tank of gas
150 lb. simulated driver (sack scratch grain plus 4x 25 weight plates)

LF 625 RF 584 53.3%
LR 533 RR 525 46.7%

Total 2267
You will come up with different numbers if you elevate the other three tires to the same level as the scale during the tests.
 

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Über Genius
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I had the other three wheels on blocks set to the same level as the wheel with the scale; I've attached an additional image where you can see that.
OK, then you did it right.

C

People tend to forget that the wheels need to be at the same level.
 

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Opeler
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As nice as the info may be, why do people keep bringing back dead posts from over 12 years ago..especially one that was actually answered.... Is real life really that boring for some of you? :confused:
 

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As nice as the info may be, why do people keep bringing back dead posts from over 12 years ago..especially one that was actually answered.... Is real life really that boring for some of you? :confused:
Catch-22. Add to an old post, get grief about old thread. Create a new thread, get grief for not searching. What's a poster to do? :headache:
 

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As nice as the info may be, why do people keep bringing back dead posts from over 12 years ago..especially one that was actually answered.... Is real life really that boring for some of you? :confused:
Catch-22. Add to an old post, get grief about old thread. Create a new thread, get grief for not searching. What's a poster to do? :headache:
Officially, if the post is relevant, it is ALWAYS better to find a related thread and add to it, assuming that the added commentary provides some additional insight or a related question

Please attempt to be more polite, Chuck.
 

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Opeler
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Officially, if the post is relevant, it is ALWAYS better to find a related thread and add to it, assuming that the added commentary provides some additional insight or a related question

Please attempt to be more polite, Chuck.
You need to get a dictionary (and not a socialist liberal dictionary either) .
I was polite.
 

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Opel Intern
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I'll post my corner weights

We have a set of Longacre computer scales at school and I have weighed my car under a number of scenarios on them.

6 gallons in the tank (drained and measured it in).
Spare tire shelf installed but no tire.
15x7 Team Dynamics wheels with 195 tires
Battery relocated to under the package shelf.
Stock 1.9 '72 GT with 4 speed in just about every other way.

No driver:

LF 552 RF 559.5
LR 487.5 RR 482.5

Total: 2081.5
Left: 49.9%
Front: 53.4%

w/ 190lb driver (thats me! :veryhappy)

LF 632 RF 564.5
LR 551.5 RR 522

Total: 2270
Left: 52.1%
Front: 52.7%

And with all of the spares and crap that I took with me on my cross country road trip plus my girlfriend in the passenger seat -> +~250lb

LF 624 RF 628.5
LR 639 RR 626.5

Total: 2518
Left: 50.2%
Front: 49.7%

What did I learn? If you look closely you''l notice the front left of the car gets lighter when you put stuff back on the spare tire shelf. This makes sense since it is behind the rear axle, I jsut didn't think it would be 10lbs lighter!

Also, 450lbs of passengers, spares, and backpacking gear seems to make the car have pretty darn perfect numbers. 50/50 left/front!? Woo! Now only if I could add 25% more power for the additional 25% weight in the car!
 

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On my 1970 GT with:

Original battery removed, replaced with 25 lb Miata battery in package shelf
No Spare tire, no jack, no shelf for spare tire
1/2 tank of gas
150 lb. simulated driver (sack scratch grain plus 4x 25 weight plates)

LF 625 RF 584 53.3%
LR 533 RR 525 46.7%

Total 2267

Dang your '70 is heavy compared to mine...
From a old post

I got my '70 GT on the scales today.
Curb with a 1/2 tank of fuel 1941 lbs.
With my skinny butt inside
LF 563 RF 547
LR 529 RR 465
That's with a relocated battery in the right rear. And no hood. I've got it off too do some repair work.
 

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Opel Intern
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...
Curb with a 1/2 tank of fuel 1941 lbs.
With my skinny butt inside
LF 563 RF 547
LR 529 RR 465
That's with a relocated battery in the right rear. And no hood. I've got it off too do some repair work...[/I]
Dan - I'd like to see your car's weights without you sitting in it. Doing a bit of back calculation using how my weight was distributed into my car on the scales, your car would show some serious weight on the RF tire and seriously light on the RR tire. The left/front balance still works out to similar to my GT, but those individual corner weights are wacky!

My 'guesstimate' of your empty car corner weights is:

LF 493.8 RF 542.7
LR 473.7 RR 430.8

Total: 1941
Left: 49.8%
Front: 53.4%
 
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