Author Topic: Overall steering ratio  (Read 16276 times)

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Offline bearingburner

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Overall steering ratio
« on: October 19, 2008, 08:09:35 AM »
We are in the process of building a 240" wb rear engine lakester. We are told to have a "slow" steering but no one we have talked with can give any numbers to "slow". IF I turn the steering wheel 360 degrees how much
should the front wheels move?

Offline Sumner

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Re: Overall steering ratio
« Reply #1 on: October 19, 2008, 03:02:25 PM »
We are in the process of building a 240" wb rear engine lakester. We are told to have a "slow" steering but no one we have talked with can give any numbers to "slow". IF I turn the steering wheel 360 degrees how much
should the front wheels move?



I'm using and others have used a rack and pinion from Woodhaven Enterprises -- 815/732-2806.  It is their 20:1 Stiletto Box (for B'ville cars ) with 5/8 X 36 splines.



The next time you are driving down the highway at 60 turn the steering just an inch or two and see how fast you turn.  You don't need fast steering on the salt.

How about some pictures of the lakester,

Sum

Offline maguromic

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Re: Overall steering ratio
« Reply #2 on: October 19, 2008, 03:11:15 PM »
I had Tony Woodward at http://www.woodwardsteering.com build me a rack with 3 degrees of steering for my roadster.  They will build it any way you want with any offsets for  mounting and the steering pinion.  They have a  LSR design in the catalog and can modify to your needs.
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Offline doug odom

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Re: Overall steering ratio
« Reply #3 on: October 19, 2008, 04:07:03 PM »
I'm sorry but I don not understand what " 3 degrees of steering" means. Steering has always been expressed in xx to 1. Meaning xx degrees of wheel rotation equals 1 degree of road wheel rotation. Anyway that is the way I learned it. Am I wrong? Would not be the first time.   LOL
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Offline maguromic

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Re: Overall steering ratio
« Reply #4 on: October 19, 2008, 04:55:33 PM »
Doug, What I meant to say is that the front wheels will move only 3 degrees left and right.  With a 6" steering arm I have 55.8 degrees of steering wheel movement, with a 7" arm 65.2 degrees of steering wheel and with a 8" arm 74.7 degrees of steering wheel.
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Online John Burk

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Re: Overall steering ratio
« Reply #5 on: October 19, 2008, 07:05:00 PM »
At 200 mph with a 12ft wheel base 1/8 deg steering is .5 lateral G's . What you'd call slow is not really slow for LSR .
John Burk

Offline panic

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Re: Overall steering ratio
« Reply #6 on: October 19, 2008, 07:33:57 PM »
.
« Last Edit: October 27, 2008, 12:23:27 AM by panic »

Offline SPARKY

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Re: Overall steering ratio
« Reply #7 on: October 19, 2008, 11:25:18 PM »
I have a chev pu that is about 32:1
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Offline panic

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Re: Overall steering ratio
« Reply #8 on: October 20, 2008, 01:48:01 PM »
Does this mean that if your steering locks limit travel to a few degrees, that as much arm rotation as can be made when seated is slow enough?

Offline SPARKY

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Re: Overall steering ratio
« Reply #9 on: October 20, 2008, 01:59:24 PM »
Depends on the car and how fast the drivers fast twitch response are  I suppose :-D
Miss LIBERTY,  changing T.K.I.  to noise, dust, rust, BLUE HATS & hopefully not scrap!!

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Offline Rex Schimmer

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Re: Overall steering ratio
« Reply #10 on: October 20, 2008, 06:43:52 PM »
If you go with something like Sum's rack and then connect it to real long steering arms the amount that the wheels actually turn will be fairly small. It is not just the ratio of the steering box it is also the length of the steering arms and any other levers that may be required.

I think that the plus or minus 3 degrees that Maguromic talks about is the total amount that the wheels will turn for the complete stroke of the Woodward r&p that he is using and my thinking is that you probably want to keep total steering below the plus or minus 5 degrees max. She ain't no sprint car!!

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Offline SPARKY

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Re: Overall steering ratio
« Reply #11 on: October 21, 2008, 12:25:05 AM »
Slow ratio with a lot of wheel cut sure makes life more plesant around the pits when you have a LWB car :-D
Miss LIBERTY,  changing T.K.I.  to noise, dust, rust, BLUE HATS & hopefully not scrap!!

"Security is mostly a superstition. It does not exist in nature, nor do the children of men as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure or nothing."   Helen Keller

We are going to explore the racing N words NITROUS & NITRO!

Offline jimmy six

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Re: Overall steering ratio
« Reply #12 on: October 21, 2008, 01:43:22 AM »
I don't know how many this will help, but I've inspected many cars with circle track "doublers" turned backwards. They all seem to like it and it really slows down the steering ratio of some of the boxes I've seen. Many were on older mechanical Schroeder sprint car boxes. I use one with a short arm and never had a problem. Make sure you have ample stops..Good Luck
First GMC 6 powered Fuel roadster over 200, with 2 red hats. Pit crew for Patrick Tone's Super Stock #49 Camaro

Offline hitz

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Re: Overall steering ratio
« Reply #13 on: October 21, 2008, 01:54:51 AM »
If you want a simple way to express the steering ratio: set your angle finder on the steering wheel at 0 degrees with the wheels straight ahead then turn the steering wheel all the way one way - write the degrees down, then turn it back through 0 degrees all the way to the other side add that to the first way.  (My lakester's total is 84 deg.)Then check the angle of the lock to lock at the wheels. (Mine was 7 deg.) I would say it was a 7 to 84 ratio or 12 to one. I have a 7" steering arm.

The reason  you turn it left and right and add the two together is to check and see if it's the same. If it's not you might find out why. Mine wasn't.

With the link steering it is a bit faster at the center. Probably not the best place to be fastest. My experience with old 912's should help.I hope I find out soon!

Harvey

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Re: Overall steering ratio
« Reply #14 on: January 20, 2009, 02:57:00 PM »
Ratio is half the battle, steering wheel diameter is the other half.  The bigger the steering wheel diameter, the slower teh total steering ratio of hand movement in inches vs. wheel turning in degrees.

A little research on this showed that with moderate sized steering wheels, many LSR cars use a ratio around 1/10th of their top speed:  >30:1 for the blue hats; <30:1 for the red hats.  In working out the numbers for 900 mph, we were settling on 90 to 120:1.  Interesting correlation across a wide speed range.