Landracing Forum
Tech Information => Steering - Suspension - Rear End => Topic started by: mkilger on May 26, 2010, 10:27:05 AM
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we have a bet going on here at my shop about steering. say you have a stock vega box with a stock steering arm, if you add a longer arm to the box will it make it faster or will it slow the steering down?? I say long will slow down. yes its on a roadster. it may be something we just have to test ?? thanks
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Long makes it faster. TWO
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Think about it, it all about wheel/tire to hand movment:
the longer arm on the box moves tire more for a given amount of hand movement
a larger strg. wheel requires more hand movment so it moves the tire less or a"slower ratio"
move the long arm to the axle and it "slows down" ie requires more hand travel
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more hand travel is what we want. but slow
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On my roadster, not the RMR I didn’t use a box, but used a Woodward rack with full rack travel L to R with 158 degrees of steering wheel. We are using longer arms at the spindle to slow it down.
Turning 3 degrees with 6” arms uses 55.8 degrees of steering wheel
Turning 3 degrees with 7” arms uses 65.2 degrees of steering wheel
Turning 3 degrees with 8” arms uses 74.7 degrees of steering wheel
Tony
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Slim I think a poll on this is needed, everybody wants slow steering at high speeds right?
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Mike
Slower steering prevents over correction and keeping the rear of roadsters following.
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Found the drawing that Tony Woodward did for me. Its a little hard to read in the picture, but on the top left it has the different arm lengths. Tony
(http://i273.photobucket.com/albums/jj236/maguromic/rackjpg.jpg)
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Mike, you are welcome to start up your own poll. We bike folks don't have the kind of steering ratio issues -- but I will say that the Bville rule for us is 15 degrees either side of center -- MAX. Not an issue except for maneuvering in the pits -- and it helps the rider keep the bike from going too far off the chosen course if there's an issue. However -- last weekend I was having my bike teched at Maxton and the guy was wondering why the heck I had the steering so limited. I explained the Bville rules -- and he darn near asked me to re-do the locks so I'd have more steering available for the turnoff at the end of the course. I didn't have to make the change, I'm happy to say -- we've got adjustment available but it takes some digging to get down to the adjusters. So -- I took it VERY carefully when I'd have to make the turnout. Long course at Bonneville -- no problemo. Short one at MXTON -- GO REALLY SLOW AND DON'T PUT YOUR FEET ON THE PEGS!
Okay, back to you car folks. Mike, start a poll if you've got the inclination.
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Longer arm on the steering box makes it faster.
Longer arm on the spindle slows things down.
Pete
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Mike,
You can do this on paper if you want. Just draw out the different radius's in 1 inch lengths, then measure the different lengths of the arc's at the same degree of movement, and you will see the longer the shaft the more travel the arm will have at the same degree of movement, and that is what everyone is saying. The longer the steering arm off the steering box shaft, the faster the steering will be.
Hope this helps.
Tom G.
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Another way to skin the cat. Get a 1 1/2 to 1 steering quicken er like the roundy round cars use and install it backwards. Then you don't have to shorten or lengthen any arms. If you don't totally understand steering geometry you can make bad things happen.
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Seldom Seen,
I seem to remember many years ago having a problem with fast steering vs slow steering on a motorcycle. After years of racing a Harley flat tracker, I built a road racer with clip on bars. Crap, you could tell my heart rate by how fast my steering flipped from side to side. And have mercy if I coughed! That thing had very fast steering! LOL DickJ