Landracing Forum
Tech Information => Steering - Suspension - Rear End => Topic started by: Huffy047 on August 23, 2012, 12:16:49 PM
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Anyone ever put coil overs (2) on a 42 type Ford straight axle? With the stock spring pivioting from the center of the frame, it seems like a tricycle to me. If the springs were kept close to the frame and out of the air I'm thinking the car would be more stable at high speed (160)?
Thoughts?
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To be competive in MOST roadster classes you will need to go to the systems that put everything in the wind shadow of the grille and axle they use coilovers doing that.
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Say a push rod arrangement? The real question is will it improve the handling?
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The handling will be more controlled with the lower end of the shocks out by the wheel or a linkage accomplishing the same thing. On the other hand if the application is lsr then you're much better off with the shocks hidden from the airflow. The handling won't be as good, but if it's engineered correctly it will be satisfactory and the ultimate speed will be higher.
Life and racing are a series of compromises. :| :| :|
Pete
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I don't know if it is allowed by the rules, but how about a pushrod-operated coilover located out of the air stream?
Regards, Neil Tucson, AZ Lake Tahoe, NV
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You mean behind the grille shell? Been done for over 40 years.
DW
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Don't forget you will need a panhard bar and while you are at it, I would suject using a Vega steering box with cross steer. Bob
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We have a panhard bar and hair pins, the goal is to make the car more stable. If I stand with my feet togather,
I can be easily be pushed over, if I spread my feet out , it becomes very hard to push me over. The stock Ford spring is in the center of the frame, so the force is in the middle of the frame? just does not seem like a good place to me.
I've built many street rods over the years with straight axles, for street speeds they are fine, this was the third trip to the salt and the fastest we have run and the car was not that comfortable to drive, and it does have a Vega box.
The nose of the car is like a track roadster with the front wheels hanging out, putting a push rod coil over arrangement inside of it would be easy and take some stuff out of the air. How ever I am looking to improve handling above aero.
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Using push rods would work well and if they were made with aerodynamic tubing they'd cause very little resistance.
Pete
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how much scrub radius and caster do you have :roll:
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A pushrod and bell-crank allows the shocks/springs to be turned 90°, so that the cross-section is presented rather than the length.
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The car left the shop to be cleaned, but the rims are 5" wide with no offset on 40 spindles, so I would say very little scrub angle, castor is around 8 deg, we had a 4 wheel computor alignment done before we left, it was perfect, weight distrubition is 40/60 with 60 on the rear.
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I would bet the scrub radius is over 3" it should be very close to ZERO when you turn the stering wheel you are "Weight Jacking the car" it hunts-- then you are "chasing it" what dia. frt tires do you have??
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When the car comes back I'll check it. I really feel it's not tht bad.
Thanks for all the input, a local racer here suggested putting a sway bar on the rear to tighten the car up, I'm looking into that.
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You cannot feel scrub radius when driving on the street. It only shows up (if incorrect) under emergencies and never is noticed if correct for your car.
You need to check it by measuring the hub and wheels.
Geo
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Geo;
A large amount of scrub radius can be felt on the street unless the street is smooth and level as a billiard table. Bumps, potholes, etc tend to pull the steering wheel one way or the other and under heavy braking it gets far worse. On the other hand, a little scrub radius is necessary to give a driver some feel as to what the front tires are doing. No bump steer gives a dead steering feel.
Regards, Neil Tucson, AZ Lake Tahoe, NV
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I know this is not the place (we have our own forum) but I race lawn Mowers and yes scrub angle is extremely inportant, without it we could not "Jack" our left rear tire up and be able to turn.
So far no one has commented on my original question:
"Would putting coil over shocks on the outside of the frame improve the handling?"
The attachment point would go from the center of the frame (like a teeter totter), go to the outer edges of the frame and be more rigid?
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Now you've made it confusing. Picture please? :? :? :?
Pete
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Outboard springs will greatly increase the roll resistance.
Is this better? Not necessarily, the chassis doesn't have much roll or yaw compared to even a street car.
It will definitely require a different suspension tune front and rear than the original bulldog center hanger.
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. . . putting a push rod coil over arrangement inside of it would be easy and take some stuff out of the air. How ever I am looking to improve handling above aero.
There's no reason to sacrifice aero to handling. If inboard springs give too little roll resistance, add an anti-roll bar. As long as you're redesigning the suspension, a straight (not dropped) tube axle is lower drag than an old dropped I-beam. (Easy for me to say, I know.)
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I was going to post s few pictures of the torsion bar front end on my roadster. Pretty clean and not complicated. But this stupid thing wont allow me to post the pictures. Says they are already posted or something. Maybe years ago. I don't remember. If you are interested email me V4GMR@yahoo.com and I'll send them.
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rename them slightly this board software is not too smart when it comes to things like that.
If you have ever posted the same image it will remember but does not link to the already posted image.
Work around is to change the name of the image slightly, or do a search of your own posts for that image and find where it was posted before.
Larry
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Rich I had the same problem and I just started naming them the date and sequence that way I don't "Duplicate"
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Richfox, tried to email you and it would not go through, please send then to tdaniels@rocktenn.com and copy to huffy044@yahoo.com
We had the V4/VGCC #508
I too having problems posting pics.
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To give you an idea of Rich's setup, a zenndog pic from page 20 of the V4 Dodge thread:
(http://i301.photobucket.com/albums/nn70/zenndog/1926%20Dodge%20Morton%20and%20Brett%20head/P1010872.jpg)
and one from page 21:
(http://i301.photobucket.com/albums/nn70/zenndog/1926%20Dodge%20Morton%20and%20Brett%20head/P1010878.jpg)
Mike
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Personally I don't like the shock nmounting or the lack of cross steering, but at the speed's that car is running, maybee it's not that big of issue.
I sure wouldn't want to hit a bad rut while driving it. jmo Bob
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looks like there is very little angularity involved with the drag link and the rotational plane of the steering arm it appears to be parallel to the ground My guess this system would not bump steer much
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Sparky, my problem lies with the parallel inboard shocks which leaves only the tortion bars to dampen at the spindle, which I don't think can work as they are really nothing more than springs in a different configuration. Like I said before, maybe at speeds under 130 or so it may not be a problem, but I sure wouldn't want to drive it with a Blown K.B. in it........ Bob
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Look closer--I think you will find the shocks mount to a "walking beam" arangement. This which mount out board on the axle and inboard on the chassis these also have a panhard duties
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The car has several runs above 200 with a best of 219. Sparky is correct the shocks are driven by rockers that pivot on the torsion bars. Shock movement is equal to spindle movement. The arms are connected to the axle ends and locate the axle in the frame. In the environment it is meant to run in it works quite well. As an off road racer, maybe not.