Rack-and-pinion with solid front axles

one of the local rodders just north of brisbane has a model a buicket with a austin 1800 rack mounted on the rear of a beam with a slip joint on the steering shaft it was built in tasmania 27 years ago and constantly apears at the nostalgic drags running low 12s so if any steering setup is causing you grief it is set up wrong ibuilt an indypendant front end in my daughters model a roadster useing wrecking yard bits sorry auto recycling facility parts out of 5 differant cars 2 enginers remarked how well the rod steerd and brake function was after 3 years and many ks never scubbed a tyre and zero bump steer

 

these guys have been selling them for awhile.
http://nolimit.net/prodinfo.asp?number=PS-SA-

 

So the decision maker is, are the tied rod ends on hub in front side of the axle or rear side of the axle hence front steer ,rear steer, MustangII/Thunderbird rack is for front steer ,alot if not most front wheel drive cars are rear steer, I have a 38 chevy with a 6" drop tube axle and Mustang II manual Rack monted insde of the front crossmember , the crossmember was notched for the steering shaft works great

 

Has anyone tried one of these 28-34 center steer set ups???

http://www.unisteer.com/1928-1940-street-rods/28-34-fords-center-steer-plain-bracket.html

 

I have the unisteer one sided rack in my avatar. I am happy with it. I see it is now available for right side steering wheel also.

 

Yeah everyone has raved about how good these are, so I imagined the center steer also had to be pretty decent? They say they've shortened it all and its center mount to eliminate bump steer, so they must be good really, just looking for user feedback. Plus the next thing would be if probably have to have it separately engineered to pass ha ha, but the clearance would be worth it

 

Here you go. There is a thread on this some time back.

 

A lot of English cars of the twenties and thirties had dreadful steering geometry. They controlled it to a point by only having 2 or 3 inches of suspension travel. This is where the myth began that you need stiff springs and shocks for good handling.

 

That was half of it. The other was too little frame stiffness in torsion to make any roll stiffness bias count.

These days it's camber recovery. Really stiff springs allow you to contain really bad camber-recovery characteristics, but at a price.

 

The flexible frame was necessary because of the stiff short travel suspension. Then the frame flex made closed bodies twist, squeak and rattle. So they invented the fabric covered Weymann body.

America took the opposite approach. Strong rigid frame and all steel body with long travel suspension, independent at the front with torsion bar to control sway.

 

European frames tended to be lighter due to fiscal regimes which encouraged smaller engines, but all ladder frames twist too much once you start inputting too much roll stiffness bias. American frames tended to be deeper for beam strength (because cheap fuel, no engine-size taxes, and a greater need for durability favoured bigger cars) but even with K- and X-members they weren't all that stiff in torsion.

Hypothetically a flexible frame would want the softest possible springing, including anti-roll springing. Unfortunately that would limit roll stiffness to a point where the car would have a constant list one way or the other, even standing still! But the capacity for roll stiffness bias is absolutely coupled to the vehicle structure's torsional rigidity - at least with conventional suspension. That was one aspect of the Citroën 2CV's brilliance: by taking the greater part of all differential roll resistance inputs out of the frame, it enabled an extremely light frame to be used.

 

back in the 70's I had a tube axle with a K car rack, perfect fit.

 

Hey Nate, not to hijack your thread but I know you and many Hambers love "specials"....well there was an episode of "Father Brown" on BBC America that had about 8-10 of them....if you get BBC and have a dvr I bet they run repeats and think you guys would like it!

 

Do you know the Specials thread?

I love specials; I also love G. K. Chesterton's Father Brown stories, on which the TV show was based. I haven't seen the show, but I'm told that it doesn't really do the stories justice.

 

I am using an Appleton rack in my Fiat. Very compact unit and built very strong. Mine is a manual rack ,but they also make power steering ones also. I believe these are used in sprint cars and in late model modifieds mostly.

 

I hope that you don't have too much wheel travel when your car is together with the weight of the motor etc in place. As it sits right now the panhard bar is going to push the axle to the left as the suspension compresses which will cause the left wheel to toe in and that will be accentuated by the short tie rod on that side swinging in a tight arc. If the panhard is level with the chassis loaded that will help but you will still have toe in. In addition the car will scrub the front tires in turns due to the ackerman being way off with those steering arms. You may also want to think about putting the axle end of the four bar in double shear. Not trying to be a dick but that is what I see.

Roo

 

Thanks

Thanks Roo,
No offense taken. Good advice is good advice appreciate it. I have made a few changes since this picture was taken and in my initial test driving I haven't noticed any poor handling yet. The double shear is in the plans when I take the car back apart. Thanks Again