Spring Smasher

Have a car with Conventional Coil Springs 10.5x 5.5. with Ford Crown Vic Tubular Lowers, and external Mount shocks. The shocks have bump springs. With a dirt late model I can take my coil over assembly and load it into the machine and get my spring loads with my bump setup. This Conventional Coil car I cannot. I can only test me bump stops. Is there a formula I can use to see what my Conventional spring would be as a coil over so I can simulate it on a smasher? I've seen Motion Ratio, Wheel Rate. Stuff but getting mixed on if and how I can use it.

If it's a 500 at 1 inch. Wouldnt it just increase 500 for every inch traveled if it's a linear spring?

Look up Keyser website. They have a load rater system for non-coilover cars.

I'm okay if people laugh, but I was thinking...for a situation like this, or even just to be a cheapskate, couldn't you take a load cell out of an old spring rate checker and somehow mount it in a shop press? Aside from taking a tape measure and checking the travel, why would anything need to be more sophisticated than that?

I know a guy that built a load machine out of a log splitter! Works good too!

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Originally Posted by missile07

Look up Keyser website. They have a load rater system for non-coilover cars.

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http://www.keysermanufacturing.com/c...l_100-7425.png

I saw this but they don’t have a lot of info on it maybe I’ll call

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Originally Posted by billetbirdcage

http://www.keysermanufacturing.com/c...l_100-7425.png

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I don't see the integra one being all that helpful, IMO. It's only gonna do static ride height load numbers for the most part. you'd be better off making a jig type deal with another clip and putting the load cell on the jack bolt and measure travel at the ball joint. Then just jack up the lower arm to get your load numbers at whatever hieght you want and just transfer those to the real car with the correct measurements off the jig cruncher.

It's more work, but the only way I really see you being able to do like we do with a coilover.

Edit: Sorry forgot your wanting bumpstop info with it. So you are going to need to build that jig differently then I described. You'd need to put the load cell under the ball joint end of the lower arm and jack under the load cell so you measuring more like wheel load. Then you could measure pin to pin measurements on the shock to use as a travel reference. Obviously it needs to be build just like the car you planning on using it for. Least if your looking for something more then static loads as this would be more similar to a single wheel pull down rig but measuring load at the ball joint but could make at the wheel if you wanted too fairly easy.

just buy an s type load cell off ebay and build a little fixture to put it in a shop press like someone said above

I was hoping I could use a motion ratio formula to see what my 500# coil spring would translate to if it was installed onto the shock and then just test it as if it was a coilover. I would only need to translate the static big coil preload into a number for my coil over assembly. I mean we can do the math for load it feels at the ball joint why couldnt we just subsitute measurements for the shock hookup or am i thinking totally wrong?

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Originally Posted by 7uptruckracer

I was hoping I could use a motion ratio formula to see what my 500# coil spring would translate to if it was installed onto the shock and then just test it as if it was a coilover. I would only need to translate the static big coil preload into a number for my coil over assembly. I mean we can do the math for load it feels at the ball joint why couldnt we just subsitute measurements for the shock hookup or am i thinking totally wrong?

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The main thing I think you need to consider is in your setup the screen doesn't move in a linear Direction in relation to compression the spring gets compressed in Ark which changes it's rate so doing calculations off of linear travel won't really get you the info you're looking for the Kyser setup will do nothing for what you're trying to do I think your best bet would be to build your own pull down rig and do like the asphalt guys do essentially check travel and pull down to that number you could build one with a couple of Harbor Freight winches and some scrap steel

This is for my asphalt car just get better info here

A typical rate calculation would be Force= Spring Rate*Distance compressed (in inches). When the spring is tipped in you have to add in a correction factor if you want to know the amount of force that is being applied in the vertical direction. Spring raters dont take this into consideration so neither should you unless you want to nerd it out. In short if you have a 500 lb spring that is compressed to 1.5" at ride height you are looking at 750lbs of load. If you want to calculate what the load is when it hits the bump spring you can PM me and i can walk you through that equation as well.

Been available from BGR since 1998 . Comes with support. 513-519--7745

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Originally Posted by 7uptruckracer

I was hoping I could use a motion ratio formula to see what my 500# coil spring would translate to if it was installed onto the shock and then just test it as if it was a coilover. I would only need to translate the static big coil preload into a number for my coil over assembly. I mean we can do the math for load it feels at the ball joint why couldnt we just subsitute measurements for the shock hookup or am i thinking totally wrong?

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I think the ratio is close to .55 for the spring to the wheel, and depending on the angle of the shock, the shock could be 0.7 to the wheels movement. In this case the spring would move roughly 78% of what the shock moves. So to simulate a 150 ride spring, you would want a 115 spring on the shock to simulate its load. For a 800 spring, it would equate to a 624, for this example. The spring does move on an arc, but to be realistic here and not get too caught up in the little (not a nice word)(not a nice word)(not a nice word)(not a nice word), soft side installed outside would allow it to compress more level anyways. I know these aren’t the exact numbers you’re working with, but I think doing it this way you won’t run into too many problems as long as motion ratio of the shock to wheel are compared to motion ratio of spring to wheel and use the difference between the spring and shock ratios to do this.