Post exact weights of weight reduction you have done!
no i do not use a lubricant. i cant see pressing to hard being the problem. maybe the guide was not center on the bit?
Last edited by EvoDan2004; Feb 2, 2013 at 09:36 AM.
As for scale accuracy:
Corner scales are NOT inherently more accurate then truck scales. They HAVE TO BE CALIBRATED to be accurate. I HIGHLY DOUBT the vast majority of none professional race team scales are calibrated.
The problem you have with truck scales is not accuracy. It is the usable range. The method used for weight measurement means you have a range where the scale will be accurate. It is generally over 10% of the max reading of the scale. Truck scales are typically meant to handle 100,000 pounds, or more. Basically, if you are under 10,000 pounds, it's probably not accurate at all because you are below the minimum calibration range.
Corner scales are NOT inherently more accurate then truck scales. They HAVE TO BE CALIBRATED to be accurate. I HIGHLY DOUBT the vast majority of none professional race team scales are calibrated.
The problem you have with truck scales is not accuracy. It is the usable range. The method used for weight measurement means you have a range where the scale will be accurate. It is generally over 10% of the max reading of the scale. Truck scales are typically meant to handle 100,000 pounds, or more. Basically, if you are under 10,000 pounds, it's probably not accurate at all because you are below the minimum calibration range.
As for scale accuracy:
Corner scales are NOT inherently more accurate then truck scales. They HAVE TO BE CALIBRATED to be accurate. I HIGHLY DOUBT the vast majority of none professional race team scales are calibrated.
The problem you have with truck scales is not accuracy. It is the usable range. The method used for weight measurement means you have a range where the scale will be accurate. It is generally over 10% of the max reading of the scale. Truck scales are typically meant to handle 100,000 pounds, or more. Basically, if you are under 10,000 pounds, it's probably not accurate at all because you are below the minimum calibration range.
Corner scales are NOT inherently more accurate then truck scales. They HAVE TO BE CALIBRATED to be accurate. I HIGHLY DOUBT the vast majority of none professional race team scales are calibrated.
The problem you have with truck scales is not accuracy. It is the usable range. The method used for weight measurement means you have a range where the scale will be accurate. It is generally over 10% of the max reading of the scale. Truck scales are typically meant to handle 100,000 pounds, or more. Basically, if you are under 10,000 pounds, it's probably not accurate at all because you are below the minimum calibration range.
Its just like some dynos are higher than others.. It should just be a tool to get you close, use the same scale and keep track of what you remove and it will give you a good idea how close it is. Not exactly the same but our home scale is different from my mother in laws and from the Dr office to the other dr office. Don't get hung up on the actual number down to the ounce or pound as if will vary from day to day based on driver, fluid capacity etc.
I don't know. That's the point, you have no idea if it's accurate or not.
It's potentially not the same as a dyno at all as far as being repeatable to its self. Well, it's like a Mustang dyno with two different operators...that's how I would relate it.
When you are outside the designed operational range, the load cells become very non-linear. This is due to the hysterisis of the load cells and the noise floor of the equipment. Basically, once you are outside the design range, you have no idea if the signal is going to be generated or read correctly and it will not be repeatable.
Now if you have your own scales, then it should be fairly repeatable if you are using them within their intended range. The one potential concern here though is you do not over range them. Load cells will take a permenant set to them if you over range them and it will throw off the calibration. If your scales only handle 1500 lb and you are driving onto them, I could see some situations where you could easily over load them. I would imagine most will roll their cars on to them, but you never know.
It's potentially not the same as a dyno at all as far as being repeatable to its self. Well, it's like a Mustang dyno with two different operators...that's how I would relate it.
When you are outside the designed operational range, the load cells become very non-linear. This is due to the hysterisis of the load cells and the noise floor of the equipment. Basically, once you are outside the design range, you have no idea if the signal is going to be generated or read correctly and it will not be repeatable.
Now if you have your own scales, then it should be fairly repeatable if you are using them within their intended range. The one potential concern here though is you do not over range them. Load cells will take a permenant set to them if you over range them and it will throw off the calibration. If your scales only handle 1500 lb and you are driving onto them, I could see some situations where you could easily over load them. I would imagine most will roll their cars on to them, but you never know.
Last edited by 03whitegsr; Feb 5, 2013 at 11:58 AM.
^^^The corner weight scales I use you jack the front & rear of the car up & lower it down onto the scales. No driving onto them. I weighed the car before I put in back in the garage for the winter. I will be keeping track of everything I am pulling off the car/changes weight wise & have a good idea where the car should sit when I'm done. So it will give me a good idea how accurate the scales are...My cousin uses the scales for his dirt car & he weighs that often, so I'm pretty positive the scales I use are accurate.
I'm not challenging you here or anything, just explaining basic instrumentation metrology ideas.
Accuracy and repeatability are not the same. Calibration ensures the scale is accurate at time of measurement. If the instrument has lousy repeatability, it is not a precise measurement the next time you use it. Likewise, you can have something very repeatable...but wrong every time too. That is why it must be calibrated to a known standard.
Calibration, quality equipment, and proper use is the only way you get precise measurements.
I know some corner scale setups use ramps so you can drive a car right onto the scales. Great for ease of use, really easy way to mess up your scales if you use them wrong though. Rolling the car on though is preferable over jacking the car up. When you jack the car up and place the car on the pads, you are restricting the wheels due to tire friction and can throw off your corner weights. Total weight will be correct, but individual wheel weights can be wrong which is obviously not desirable if you are corner weighting the car. Either way, man I wish I had a set of corner scales.
This would probably be a better topic for the motorsports area though. Might be useful information when you shell out $250 to have your car corner balanced and the first thing the tech does is drive the car on the ramps at 20mph and then tells you your car weighs 100 pounds less then last time you weighed it and nothing changed.
Accuracy and repeatability are not the same. Calibration ensures the scale is accurate at time of measurement. If the instrument has lousy repeatability, it is not a precise measurement the next time you use it. Likewise, you can have something very repeatable...but wrong every time too. That is why it must be calibrated to a known standard.
Calibration, quality equipment, and proper use is the only way you get precise measurements.
I know some corner scale setups use ramps so you can drive a car right onto the scales. Great for ease of use, really easy way to mess up your scales if you use them wrong though. Rolling the car on though is preferable over jacking the car up. When you jack the car up and place the car on the pads, you are restricting the wheels due to tire friction and can throw off your corner weights. Total weight will be correct, but individual wheel weights can be wrong which is obviously not desirable if you are corner weighting the car. Either way, man I wish I had a set of corner scales.
This would probably be a better topic for the motorsports area though. Might be useful information when you shell out $250 to have your car corner balanced and the first thing the tech does is drive the car on the ramps at 20mph and then tells you your car weighs 100 pounds less then last time you weighed it and nothing changed.
Last edited by 03whitegsr; Feb 5, 2013 at 12:55 PM.
Good info into the break down in regards of truck scales. , On to corner balancing most don't realize the variables when corner balancing. The hard part for most is once making an adjustment is remembering to resettle the suspension.
Anyone weigh several FMIC options? Ive been reluctant to upgrade since most I've seen are about 20lbs and stock is ~10lbs. Thats 10lbs at the nose of the car Id like to not add...
No matter what upgraded FMIC you purchase you will be adding around 10lbs+ to the front of the car, obviously depending on the size of the core, etc. Personally I would rather have a better quality FMIC that weighs a little more over a crappier quality FMIC that weighs less....