Landracing Forum
Tech Information => Steering - Suspension - Rear End => Topic started by: bearingburner 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?
-
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?
(http://purplesagetradingpost.com/sumner/bvillecar-2/steering-3.jpg)
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.
(http://purplesagetradingpost.com/sumner/bvillecar-2/tierod-3.jpg)
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
-
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.
-
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
-
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.
-
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
-
.
-
I have a chev pu that is about 32:1
-
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?
-
Depends on the car and how fast the drivers fast twitch response are I suppose :-D
-
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!!
Rex
-
Slow ratio with a lot of wheel cut sure makes life more plesant around the pits when you have a LWB car :-D
-
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
-
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
-
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.
-
Interesting input , Blue, even though "empirical", I'm assuming, but some real food for thought.
Stimulating!
-
empirical i like that has a nice sound empirical racing willie buchta