Hot Rods Rack&Pinion

Looking to install a rack&pinion on my 26 T touring with 4in drop tube axel. Want to use cross over link to stiffle bump steer. I'd like to attach r&p to the frame but I've heard some concern that if I use the hairpin wishbones they may become a problem. Any thoughts? I'm one of the new guys on the block and sure appreciate any help I can get. Thanks, Jet Car Bart

 

There are a couple of ways to combine a R&P with a Tube or Ibeam axle.


Lengthwise ( like it was in the Instant T )


With a kit like the one in the Thread you posted on earlyer.


R&P on the frame - will give m***ive bumpsteer.


R&P on the axle itself - There are probably going to be a couple of guys that will tell you this works great, and they put a lot of miles on a setup like that.

But you will need some sort of a silder in the steering column that doesnt bind when there is a load on it, and the Double D GM silder ( for example ) is not designed to do that.

 

Every one I have seen hanging on an axle stuck out like a big sore thumb. It may work but on the list of clean and attractive it is way down at the bottom.

The new cross steer rack might be nice but as mentioned earlier you would have to run a proper linkage to keep it from pushing the whole axle sidesways.

Mounting the rack on the frame and attempting to steer a solid axle rig is just asking for trouble as metalshapes mentioned.

 

I'm not sure what you mean in your second paragraph. I guess cross steer systems have been moving the whole axle over since '35?

Charlie

 

The joint straight off the rack on an XJ6 Jag would be ideal for this situation as it was designed to allow movement the same as what would occur with a tube/beam axle.

 

Thanks for all the thoughts----looks like Vega & draglink. Thanks again, Bart.(this is a great site)

 

Unisteer
Check it out

 

Allright...


Prove it.


A key feature of an I-beam is that the wheels stay at the same distance from eachother.

So if we ***ume for a minute that the axle moves straight up and down, you have a problem if you want to connect each wheel to one side of a R&P.
To have No Bumpsteer, you would have to have infinitly long tie rod ends coming off the R&P ( which you dont )

If you get fancy with Panhard bars, etc, you can get one side right.
But then you loose the advantage of the Bumpsteer of both wheels canceling eachother out.

(which is probably what your car was doing, and why it preformed OK...)

 

Looks like your quoting ME there Alex!!!!

 

I dont mind doing that, because you know what you are talking about...

 

Thanks...but I mean MY name is on HIS quote in your post...#13!!!!

 

Ahhh...

Corrected.

 

I have used rack on tube and it works very very well.

 

Bart, my friend has a Dodge Colt rack attached to his 4" tube axle in his 33 coupe. He is using Econoline spindles and a slip joint on the steering shaft, it steers like a dream and has been in use trouble free since he built the car in 79.The car is fenderless and with the axle and rack both painted black, its virtually non-existant unless you really look. The only trouble is there may be a bit of a problem in some areas finding a rack for a mid 70's Dodge Colt !! Mike.

 

Unless you can explain how you can match a suspension point that moves in a liniar line ( measured out fron the centerline of the car ) and a suspension point that moves on an arc ( measured from the centerline )
absolutly 100% perfect, you have not proven anything...

If those 2 point do not match pefectly over the complete suspension range, you have Bumpsteer.

Just because you are not aware of it doesnt mean its not there.

Put a Bumpsteer Gauge on it, and you will see...

 

Just take a picture...how hard is that?
As for "misleading" someone...YOUR the person bucking the common opinion on frame mounted IFS style R&P being used with a straight axle!

I'm sorry, but without pictures...

I'm sure there are ways to do it with some high tech wizardry, but as a simple bolt in conversion of existing parts to a car with reasonable suspension movement, its not a good choice.
On the axle...sure...just address the slipjoint issue safely and ignore the unsprung weight increase and it works. I know people who have done it in the past and raved about it.

At the very least...what's your rack from and how is it secured to the frame???

 

The best thing I did to my coupe was installing a Unisteer R&P.

 

Hackerbilt; You went on another thread and twisted what I said around, changing the meaning. Then you said on that thread that I bailed on this thread. Your arrogant twisting of the facts to bolster your side of the discussion, as if I am a ****ing idiot and you know already that my frame mounted R&P on ‘beam axle won’t work. Without coming right out and saying it you are calling me a liar.

Then you want a picture? Why would I go to the trouble………….?

 

I know this wasnt directed at me, but since we were having this discussion I might as well answer as well.

No, I do not think you are a liar.

What you do have is a built in mis match in steering geometry.

That doesnt mean your car cant perform OK,
If you have limited travel, reasonably long tie rods, and a good positioning of your R&P, it might be acceptable.
Trailing Arm Volkswagen front suspensions have the same kind of mis match, and they sold millions of 'em...

(but they have plenty of Bumpsteer and I've talked to Formula V racers that did what they could to minimise it)

So my advise to stay away from that setup was because, unless you are aware of the shortcomings of that particular type of setup, you are very likely to end up with a very bad handeling car.

So you must have been, or you were very lucky....


I hope with all of our input, the Original Poster has enough Information to make his decission.

 

Its a racecar that uses Trailing Arm Volkswagen front suspension.

Which is a system that has the same kind of flaw as the setup you are in love with...

 

metalshapes; what is the rambling about Formula V and all that? Oh, please don't answer that, even though it has absolutely nothing to do with my OFF TOPIC '29 Chivvy with I beam axle and frame mounted R&P.
Remember why I chimed in on this to start with?
It was because you said about straight axle R&P, "……………R&P on the frame - will give m***ive bumpsteer…………”

Other than to repeat myself, and why should I have to, but I will, You are wrong. Throw in all the red herring you want to, it's not about the history of the system, it's about your incorrect statement.

I'm not here to offer any more than what I have already said.

Sigh...............
Goodby...........

 

This Thread would be a lot more readeble if you wouldnt change and delete your posts, after they have been replied to.




Have fun, you are far enough away, you wont have your accident in front of me...

 

Hi Bart , I just installed a Unisteer Rack in my 32 Truck .
it bolted up to where the Vega box was .
There was lots of clearence at the motor and with the vega box kit hooked up to column with no trouble.
This kit comes also with the tie rod ,I used my old tie rod end to connect to the axle . it took 2 hours to remove old vega box and tie rod and install the Unisteer rack . This set up steers great .
John.

 

I like "racks" on my womens chest............does that count? But I guess it does lead to "bump steer"..................

 

Had to mock it up for those that don't understand what bumpsteer is on a frame mounted rack for a beam axle car. It does exist, this shows 3 degrees of toe change in less than 2.5" of travel on both sides. That's a lot of bumpsteer!

set up in a "static" or neutral position. No toe change:





Set up in a compressed position. Note: toed out,