Hot Rods Cowl Steering . . . just stop !

fine I wont post anymore on this site if its just a place to chew people out I'm a designer and I guess its time to leave the hamb

 

I'm pleasantly going to ask you to read this complete thread and then rewrite your response and enjoy the Hamb...knowledge is golden...

 

its all good
this place plays hard
its like working in a shop
I've been crapped on more times than a statue

 

Man...That's the third designer to leave the HAMB this month!
Looks like we'll all be reverting to T squares and 30/60s. (that's the plastic asymmetric triangle)
When these old relics were designed on drawing boards, CAD application is like taking a scanner to the flathead...

 

Thanks Pete.

 

I got it. I was getting it but the animation helped me explain " the other factor" that has been the source of some contention.

The human factor of perception.

The driver absorbs the bump steer and corects for it without conscious thought. The driver is in motion as well. A dip, the driver turns slightly left, then right. He does this without a thought.
So when he says the car drives well, so it does in his perception although the bump steer still exists.

Imagine walking across a pasture or field instead of climbing a mountain. The pasture is a " smooth" walk although in reality there are dips, holes and uneven ground that the brain corrects for automatically, just in the processes of balance correction.

 

Designer or not,
Dropping in on page 9 without obviously reading anything prior is really sort of annoying.

 

Good point.
The geometry of the front suspension is what defines "bump steer". The amount of bump steer is defined by how much the geometry of the specific car deviates from the ideal. Other factors can mask the issue; lack of suspension travel, etc. It seems when some people hear "bump steer", they assume that all cars with bump steer will jump and change lanes when hitting any bump in the road. If their car doesn't do that, then they got lucky and don't have bump steer, even though the geometry indicates that they do.

 

Surely the Bump Steer 2 animation is a matter of case (thread?) closed?

Shame that it had to get silly in the interim, but in all honesty that was inevitable.

Looking forward to more education. Bring it on Pete.

Chris

 

Haha, dude no need to get your panties in a twist, just read the thread. What you posted was dealt with conclusively, and you wouldn't have posted it IF you had read the thread.

 

Reverting?

 

I'm sure someone smarter than I am can tell me if bump steer is worse or not with quarter elliptic suspension as opposed to stock Ford factory type suspension with a single pivot point.

 

It means you verted once already.

 

Ha ha. I mean I still have a T-square and 60/30 (and 45). Yes, I am still on the original vert.

 

Is your 1/4 elip spring acting as a suspension locating member, or just acting as a spring?

If the spring is just a spring, it will have no effect on the amount of bump steer.

 

From what Pete has said explicitly and out right and implicitly by saying jump on the cars front end and watch the wheel and then the added animations,,,,

If one were to firmly grip the wheel, the car would wonder left and right at a minimum or possibly dart and change lanes as the road dips and suspension movement forced a change at the spindle.

However allowing the car to follow the road while remaining on a relatively straight path requires the driver to let the steering wheel float with a loose grip as the road dips and suspension movement forced a change at the steering wheel.

Those are the 2 ways to experience bump steer, and the only two that I know of.
The degree of bump steer , maximization or minimization depends on the amount of suspension movement and the amount of discrepancy of the arcs or deflection of other components.

 

I’ve been really interested in the bump steer discussion and since I have the radiator off my car, I decided to see just how bad it is. I’ve been driving it for about 20 years like this so it’s time to find out. I began by making a quick wire pointer going to the steering wheel and marked its location on a piece of tape. Then I compressed my spring using two pipe clamps. Although there was 2.5” of potential travel I compressed it only 1.5”. Possibly the shocks would not allow any more movement. The steering wheel moved so that the mark had moved 7” around the wheel, steering to the left. I think this is about 45 degrees. The steering box has 3 turns lock to lock. Since this is the only car like this that I have ever driven, I don’t know just how bad it is. But I would like to make it better if that is possible. Thanks for any suggestions.

 

HFH,

A couple of suggestions, would take you a couple of different routes...

Suggestion 1: you could relocate your steering box higher (like HollywoodTuck did), mounted partially on top of frame rail. You would be trying to get the bottom of the pitman arm to fall along the line of the stock mounted wishbone...

Suggestion 2: split the wishbones, and bring the mount out to the side of the car. You may need to cut the welds at the front of the bones, so you can change the angle slightly to get good axle caster, and also put the bones at the angle you want aesthetically...
You can then see where bottom of pitman arm is, and if it’s lower than wishbone line, a little heat and kink can bring it up some (this is assuming box is still in stock position)... if you kink the pitman to shorten, you will need to alter (shorten) steering arm on back of left spindle to keep geometry good


Sent from my iPhone using The H.A.M.B. mobile app

 

Here's a picture....It seems to me that the quarter elliptic springs are acting both as a locator and a spring. The wood is only a pattern for the MG Midget/Sprite shocks. Thanks in advance for your thoughts.

 

Your hair pins are your axle locators. Your 1/4 elliptic springs are just springs. They aren’t contributing at all to more or less bump steer. What indicates bump steer is how far your pitman arm/drag link joint is away from the hair pin to frame pivot point. Yours is closer than some shown on this thread.




Sent from my iPhone using The H.A.M.B. mobile app

 

Geez, lotsa big words being used here....starting to scare me......maximisation, minimisation, discrepancy...I'm gonna go hide.

 

A lot, a little, different....So come on out.

 

Could it be asked to see a couple animations of non bump steer setups? one being a cowl steering and the other vega box steering. Or the best/closest to correct as possible?

 

Bump steer is so bad in Australia they have to use road signs. Sources state they will correct it by teaching cows geometry.

 

hey man, it's ok to be scared but it will be ok- I promise.
At one time in your life the scariest thing ever to you was using the potty, and that really wasn't so bad was it.

 

When my friend did it, I thought it was o.k.

 

Look at this one. It’s cowl steering set up for minimum bump steer. It looks a lot like a box mounted on the frame.
Vega cross steering is another topic.




Sent from my iPhone using The H.A.M.B. mobile app

 

I have several hot rods with Vega steering, but when I built this black 27 with the flathead I was forced to go cowl steer to make room for the radiator. About 30 freak'n hours to do it. The steering box is a 53 Willys Aerowing which I really like. The # 525 lakes modified is a Vega box mounted sideways. No bump steer here.

 

Wicked looking cars man...both of them!