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PostPosted: January 25, 2017, 5:00 pm 
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Is it possible to get a 1:1 motion ratio on an outboard coilover? I don't really see anyway to actually do that.
I was referencing this http://www.truechoicekoniracingservices ... ksheet.pdf


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PostPosted: January 25, 2017, 6:52 pm 
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In short, no.

The longer answer is that you can get very close, but it means making the shock both as upright and as far outboard as possible, which interestingly ends up being a McPherson strut. That said, if you're willing to change to an inboard or rocker-arm setup, then yes it's possible.

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PostPosted: January 25, 2017, 7:42 pm 
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Bummer and it's a no go on the inboards.. But you can make it progressive right??

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PostPosted: January 25, 2017, 7:51 pm 
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Rising rate, yes, if the top of the shock is placed such that shock shaft movement increases with increased bump. Unless you mean "progressive" as in spring rate, then you can cheat and use progressive-wound springs.

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PostPosted: January 25, 2017, 7:53 pm 
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It's also possible to stay outboard with a 'rocker' setup: http://www.kineticvehicles.com/dds.html

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PostPosted: January 25, 2017, 8:30 pm 
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KB58 wrote:
Rising rate, yes, if the top of the shock is placed such that shock shaft movement increases with increased bump. Unless you mean "progressive" as in spring rate, then you can cheat and use progressive-wound springs.


Correct rising rate. The same as I did on my car. I will play with the shock in solidworks and see what I can come up with.

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PostPosted: January 25, 2017, 8:45 pm 
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Stohr race cars outboard rocker -simple and effective


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PostPosted: January 26, 2017, 12:36 am 
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Yup, I completely forgot about that one. It can really mess with one's head about what's going on but it really does work.

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PostPosted: January 26, 2017, 8:55 am 
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Yeah that design won't fly with my dude...

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PostPosted: January 27, 2017, 7:16 pm 
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why doesnt your Dude like the design? Its a nice compact, simple solution which allows the springs and shocks to work their best. The Stohr cars are VERY well designed - you can find pics online. I have a friend with one - it has a GSXR 1000 and goes 185mph. It runs wheel rates of close to 2000lbs to keep the ride height consistent for the ground effects.


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PostPosted: January 27, 2017, 9:30 pm 
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The nice thing about that setup is that it easily doubles the motion ratio. People worry a bit too much about leaned over shocks. It's not perfect, but my formula car has a little less than 45 degrees if I remember right and it ran quite well in it's day including winning a national championship...

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PostPosted: January 28, 2017, 1:41 am 
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It would be interesting to build a plywood and stick mock-up of the Stohr setup and measure spring compression vs wheel height change for a couple of different configurations.
Probably could also do that with a spreadsheet, it's just triangles in two different planes. And you could plot the results.

An intriguing arrangement, but I'm beyond that point in my build. :(

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PostPosted: January 29, 2017, 9:23 pm 
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Sean in CT wrote:
why doesnt your Dude like the design? Its a nice compact, simple solution which allows the springs and shocks to work their best. The Stohr cars are VERY well designed - you can find pics online. I have a friend with one - it has a GSXR 1000 and goes 185mph. It runs wheel rates of close to 2000lbs to keep the ride height consistent for the ground effects.


He thinks it's complicated and ugly. Not too much I can do to convince him.

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PostPosted: January 30, 2017, 10:49 pm 
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...and the bellcrank doesn't necessarily need to be 1:1. Plus, depending on where the holes are, you can get some rising or falling rate out of it.


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