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PostPosted: January 30, 2018, 1:58 pm 
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Joined: August 21, 2017, 7:37 am
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Curious out of my mind on what my project weighs so far. I also needed a better guess on the weight since im ordering a set of custom Feal coilovers to fit my lowered ride height and might as well get them valve properly.

I've looked for scales several times and almost bought a full set of actual corner weighing scales but kept dragging my feet. So i looked one more time last week and saw these PCR-3115 scales rated to 300kg. Yes 660lbs. Which is way higher than I've seen the last few times i looked. They also had the readout on a wired control box so i didnt have to try and read the number under the tires. So i order two of them at about $35 a bucks a piece on ebay and they got here 2 days later.

Link to scales (although i ordered them off ebay) https://www.tmart.com/PCR-3115-300kg-10 ... 54706.html

Today. I tried them on myself, one read 188 pounds, the other 192 pounds so precision is what you get for $35. Now theres a calibration option where i think i can put them in sync with each other, i have not tried yet since I'm at work and just got them. Later tonight i hope to put them under my wheels. Hopefully these work out better than the carbide miter saw blade in a wood saw.


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PostPosted: January 30, 2018, 4:32 pm 
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Interesting. Thanks for the tip.

It got me looking around and I found something similar on Amazon. Not as much capacity but might still be enough for many locosts. And it has a relatively good amount of decent reviews.

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PostPosted: January 30, 2018, 4:45 pm 
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The only thing im worried about is when i lower the front wheels down onto the jack that the sideways force as the control arms swing out will over load the legs. Alternative is to set them at the edge of garage where i can roll car out onto them pretty evenly.


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PostPosted: January 30, 2018, 5:13 pm 
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Nice scale. :cheers: I wouldn't worry too much about that small difference. If you're running at Indy, maybe it is an issue.
As to the scale sliding, you could put the scales on something more slippery than your garage floor. Most people have to use shims to get them level side to side, and I have heard that vinyl flooring tiles work well. They will also let your scale slip a little.

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PostPosted: January 30, 2018, 8:15 pm 
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Round one didn't go so well. I lowered the car down on 4x4's then rolled it onto the scales. RH measured 606, LH 556. Was like wow, that's high and big difference. There is a big arse turbob that favors the RH side though. So I switched sides and in the process wrecked both 5v adapters they plug into. But the measurements followed the scale, so now LH weighs 600. Ugh. Still much heavier than I thought but Im going to get batteries to power them and retry. LH rear, 320.


Last edited by terryjr on January 30, 2018, 8:26 pm, edited 1 time in total.

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PostPosted: January 30, 2018, 8:17 pm 
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4# at 190# net is 2%, you are not going to get better than that for so little $.

To negate the side load you could lift the wheel with a strap with your engine hoist (if you have one...) keeping the suspension loaded so it does not swing through an arc.
Or make 4 blocks ~ the same thickness as the scale and roll from them to the scales.

edit: While I was typing you posted your 4x4 try... that's a bigger % difference for sure.

Although it doesn't make the actual number any more accurate, swapping the same scale corner to corner with blocks under the other 3 wheels would at least make the errors similar (assuming that when you put the same scale under the same wheel you get the same result... something that would be worth a try).

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PostPosted: January 31, 2018, 8:37 am 
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Reading over the instructions again. I may have had the scale in "precision" mode. Theres a "high capacity" mode. I dont know what mode it was in. It was 14 degrees in my garage last night so i didnt spend a lot of time. I'll try again tonight, supposed to be a warm 47 today.


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PostPosted: January 31, 2018, 8:45 am 
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duratec7 wrote:
4# at 190# net is 2%, you are not going to get better than that for so little $.

To negate the side load you could lift the wheel with a strap with your engine hoist (if you have one...) keeping the suspension loaded so it does not swing through an arc.
Or make 4 blocks ~ the same thickness as the scale and roll from them to the scales.

edit: While I was typing you posted your 4x4 try... that's a bigger % difference for sure.

Although it doesn't make the actual number any more accurate, swapping the same scale corner to corner with blocks under the other 3 wheels would at least make the errors similar (assuming that when you put the same scale under the same wheel you get the same result... something that would be worth a try).


^1

Further, you could add up the 4 numbers, then go to a truck scale and compare that to the sum of the 4 for correlation adjustment to the real corner weights(if that is important to you). One important thing that Duratec7 mentioned, you should weight the same corner several times to ensure that your technique isn't adding any undue variations.

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PostPosted: January 31, 2018, 9:26 am 
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WARNING You need to be aware that most garage floors are not close to level and have a lot more slope then you realize. I actually had one wheel location that needed over a 1/4" to bring it up to level. I would suggest that you level within a 1/16 or less and then mark your floor locations and label the shim packs so the car can be easy to re-set on the scales. When jacking the vehicle up and down it does not also settle at the same ride height every time. You need to drive the car a short distance and re-verify your adjustments because of the friction in the bushing and coil-over static adjustments during the set-up, does end up being the same dynamic ride height after a short drive. Dave W


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PostPosted: January 31, 2018, 9:54 am 
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Im not going for precision but i was hoping to be with 20 pounds or so. Its mostly for my own knowledge of the vehicle weight and to know if the coil over supplier should be picking between a 4k/5k/6k etc spring rates for each axle.


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PostPosted: January 31, 2018, 10:43 am 
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I'm all for saving money and went round and round trying to find a way to not buy proper corner scales - I failed. My brother and I split the cost and we never looked back.

Regardless of cost, a level surface is a big deal. Consider a car with a wheel rate of, say 150 lb/inch. If that wheel is even 1/8" off compared with the other wheels, it induces an error of 150/8 = 19 lbs.

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PostPosted: February 1, 2018, 9:23 am 
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If you are only looking at getting within 20lbs, then flat flooring should work.
My first set up I just flat floored the car and it was within 18lbs, when I did the corner wt with scales.
Now I did use a transit to set the leveling pads, but I just strung fishing line between the pads and measured off the line.
Eye balling with a ruler I probably was only within 1/32".
To be honest I could not tell the difference between the two set-ups.
Disclaimer even my middle name is not "Shumacher" Dave W


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