Twin_Turbo this is not discussed much and I think most people don't worry about it. If you run the 550 springs you get very little movement in the front end so pump steer is minimul. I run 280 pound springs in the front end for a smoother ride so bump steer is definitely important to me.
I want to have lots of wheel travel over rough roads and zero pump steer. It really makes a difference is weather you control the car or not over rough roads at high speeds.
This winter I will know alot more about what needs to be done. I do have everything ready for check very accurately bump steer. Like Pete I have the fixture, the aluminum plate and will take the time to remove the spring and do it properly. I will experiment on longer tie rods and their relocated inner mounting point.
While it may not be enginered it will be maticulously researched and all welding will be done right.

 

When I put in the Jeep Steering box all of my slave parts go away. I will have a manual steering link and nothing hanging off of it.

The frame mount for the steering box will be really heavy duty. It will even go above the frame rail and have a twin gusset supporting the top.

I could float the box up and down with a mock up plate and then when I find the sweet spot put in a permenant plate with that mounting location in it.

Using an extended spindle and then working back from the spindle and positioning the Pittman and Steering box to accomodate a desireable point of coinnection. Then adjust the length of the tie rod sleeves and it should be what we are looking for.

I plan on putting on the VBP front upper and lower tube a-arms and hopefully a set of extended spindlesbetween them and then fab everything to match that. Jim

 

Up until reading this thread I had no idea what bump steer was. What I did know is how strangely my car behaives on a couple hills on the road I take to work. Right as I hit the top of them the front end wanders. I never thought about what was going on. Does the steeroids kit help this problem at all?

I assure you Norval, more people will be concerned when they learn what is happening.

 

Cookwithvette. It is a major problem that most do not even know exists and I have learned about it over the last year from my stock car friend Roger, reading books and talking to people on this forum in particular Pro South (Jim) Pete, Twin_Turbo, and Mrvette.
I have also experience a very near accident at 100 mph with 2 yes 2 passengers on board
Right now I probably have the most work in trying to make our existing system work and get rid of most bump steer but over the winter I hope to totally eliminate it.
That same dip and bridge that almost caused me to crash years ago can be taken today at the same 100 mph and the car takes it smooth and true without any sign of darting anywhere.
I have my bump down to within .015 inches of toe change. It's the bump up I need more work on. I have gone from 1 and 3/4 inch toe in to 3/8th of an inch.
A big improvement but still not close.

 

Jim I would mount the steering box in the best location , or at least that the steering column in aligned and header clearance is an issue.
The center link can be modified for the right inner tie rod height very easily once you know where that is.
What are you going to do for extended spindles? I am definitely going to jig the stock units and add about 1 inch to their length. I know that I can weld the stock units to equal the strength of the original pieces, that is unless they prove to be cast iron in which case I wouldn't touch them.
Jim you will also need a proper bump steer fixture to do it right or buy one for a couple of hundred dollars.
I will definitely keep the forum posted on all modifications along with pictures when the time comes.
Right now the quickest easiest aid to the steering to is to remove the upper A arms, slotting the holes 1/4 inch to the rear, or replacing the cross shafts with replacement shafts with the hole already moved back to improve camber to 5 degrees positive.

 

Finally got this dang LuvWorm out of my computer. I had it to the Doctor before the patch came out, I needed to reload some files anyway, so he wiped it and I lost several files that I didn’t have backed up. I may need to get Marck to pass me the front suspension picture that he geometrically marked up for us again.

Jim I would mount the steering box in the best location, or at least that the steering column in aligned and header clearance is an issue.

I may use a non Corvette steering column that terminates at the firewall and use a connecting link to attach the column to the 2002 Jeep 3 turn, high effort steering box. That will alleviate any attachment / alignment problems.

The center link can be modified for the right inner tie rod height very easily once you know where that is.

The idler, etc can be re-located very easily to match any re-application of the steering box. The manual steering center link I believe can be easily altered in length if needed.

What are you going to do for extended spindles?

I have a friend in Canada that may help me with this…………….

I am definitely going to jig the stock units and add about 1 inch to their length. I know that I can weld the stock units to equal the strength of the original pieces, that is unless they prove to be cast iron in which case I wouldn't touch them.

With the Van Steel upper and lower control arms I think I could adjust them to accept other spindles and ball joints easily. I will have to look around and see what may be compatible. I know that Chevrolet ½ ton pick-ups share many parts with the Impala front suspension and big brakes so that may be a good place to look. If this doesn’t work I may create a “Well” for the upper ball joint to mount in the top Van Steel A-arm. It would be easy to put a drop in the upper mounting plate and add an inch there instead of a ball joint extender or spindle length extension.

Jim you will also need a proper bump steer fixture to do it right or buy one for a couple of hundred dollars.

Lots of stock car guys around here and they have all of the goodies to do suspension adjustments.

I will definitely keep the forum posted on all modifications along with pictures when the time comes. Right now the quickest easiest aid to the steering to is to remove the upper A arms, slotting the holes 1/4 inch to the rear, or replacing the cross shafts with replacement shafts with the hole already moved back to improve camber to 5 degrees positive.

I think my tubular arms already have this incorporated.

Norval I am sending you a link to Classic Industries Camaro parts. They have a trick set of 92-02 Camaro upper and lower A-arms that are fully adjustable with heim joints at each of our bushing locations. Pretty slick looking. Might look at them and see if the concept will share with ours.

I also have the two lasers I bought to set up the rear six-link that has the levels built into it and an alignment stick for toe.

I also think that the Van Steel Mono-Spring front will allow much more flexability in building this than using conventional coils by being able to remove spring tension with only loosening a bolt rather than removing the spring.

I believe that the easiest and probably safest alteration is to the tubular a-arms.

Jim :seeya

 

It would be easy to put a drop in the upper mounting plate and add an inch there instead of a ball joint extender or spindle length extension.

Jim if I am reading this right you intend to try cheating and just dropping the mounting location in the A arm so while the A arm appears to be pointing down it is not. It would not work. The line through the upper pivot points is what counts not how they look.

will definitely keep the forum posted on all modifications along with pictures when the time comes

I lied. I have spent 3 solid days changing tie rod lengths. It involves a longer sleeve and a new mounting point on the center link. I made my 4 of these changes in the last week.
I have tried 4 different lenths of sleeves and moved the inner mounting points 2.1 inches, then 3.1 inches and finally 4.1 inches. I also tried different outer tie rod heights. It involves alot of modifications, alot of taking the front end appart and finally the accurate testing.
Stock my total pump in at 3 inches rise was 2.25 inches. Yes over 2 inches of toe in, I slowly reduced it to 5/16th of an inch with the inner tie rods moved in 3.1 inches per side. At 4.1 inches per side the bump steer started to increase again.
I do have the advantage of a super good hoist, extremely rigid, level and parallel. Like everything else around here it is home made and I was very fussy about it's alignment for a referrence for suspension modifications.
My center link is done, my tie rod sleeves are 14 inches long compared with stock ones around 10 inches or something like that.
I did run a new mustang on the rack and it's rack and pinion bump steer was 3/4 inch at 3 inches rise.
My vet bump down it .015 at 2 inches.
I also used the pump steer studs on the outer tie rods and lowered the outer tie rods 1.250 inches lower then stock and this seems to work. On monday I will remove both steering arms and weld permanent mounts unto the stock steering arms that have the 1.250 incorporated in them. While outer steering studs work fine I do not recommend them for continual use at this level.
I do drive 130 mph and unless everything is extremely heavy duty and rigid I do not trust my life to it.
Jim I have been obsessed with front ends this entire summer and continually strive to improve what I have and it is working. A 100 mph whoopdy doo? does not affect the car anymore and it will just let the soft springs do their job and there is not feed back into the steering.
While I still have 5/16 inch bump in the car at 3 inches you do not feel it under any circumstance.
My feels it that heavy springs just mask the problem by tieing the suspension down, not allowing it to work. If you eliminate the problem you can run soft springs and get a good ride.




[Modified by norvalwilhelm, 7:21 AM 8/16/2003]

 

Jim if I am reading this right you intend to try cheating and just dropping the mounting location in the A arm so while the A arm appears to be pointing down it is not. It would not work. The line through the upper pivot points is what counts not how they look.

Yeah, I don't know what I was thinking, you are correct it's the distance between the pivot points that has to be extended to create the lines needed.

I do wonder about donor spindles and brakes though.

I think I will go to the salvage yard and look around and see what may work. JIM

 

Jim our steering arms bolt to the spindle and also our upper caliper mounting plate bolts to the spindle. The donor spindle would have to give you new steering arms and brakes.
With hydraboost, stainless calipers and properly set up wheel bearings and shimmed rotors I don't thing our brakes have a problem. Mine stop great without the least shimmy or pull. And the wheel bearings must be set up right, NO BACKING OFF TO THE NEAREST COTTER PIN.
As for welding our spindles what is wrong? Properly jigged and welded and they are as strong as original. You are adding the extension above the existed caliper plate mounting bolt, that is the big bolt at the top of the caliper and the load up there is not that high. Look at the ball joint, it is not that beefy and all the welded extension has to do is hold the same load as that little ball joint.
If you look at a tie rod they look fairly beefy? Wrong, take one apart and it is necked down to about 3/8th inch just before the ball. Under the boot and all that grease is a small neck. I know that isn't a ball joint but the ball joint is the same deal.
The loads on the upper A arm are not that great that a properly welded spindle would have the least problem with.
And you know the stock spindle fits. I know you have hydraboost but don't think you have it installed. Give it a try with good calipers and trued rotors and then complain if you don't like it.
Have a nice day Jim
Norval


[Modified by norvalwilhelm, 11:02 AM 8/16/2003]

 

Just looking for another angle on this. I know all you said and that it is true, but sometimes a process is improved upon.

I wasn't complaining about the present brakes, just stateing that again they may be improved on or at least maintained with a donor front suspension upgrade.

We ran what we called "Drop Spindles" 35 years ago. We extended the front spindles on the old shoebox chevys 55-57 to raise the front end and not to cure bumpsteer. We actually combined two spindles. One standard from the original suspension and another welded as a leg off of it to raise the front end about 4".

There was a good welding shop on base here and they would sneak them in and weld and x-ray them for us. I'm sure that was much more dangerous than a simple internal length extension.

I really think that a set of extended spindles will do the trick, but I still like to look around. JIM

 

Dropped spindles are not extended spindles. Read one of the articles you sent me and they go into drop spindles vs extended spingles. Dropped spindles do nothing for bump steer. They lower the car.
The donor spindle graffted onto another spindle is a great idea and actually that is what I would do rather then actually making a slice adding a 1 inch piece and making 2 welds, I would just cut the stock spindle off as high as possible and use another donor spindle cut as long as possible or at least the length I wanted and weld it on for a one weld only.
I will make jigs first for alignment.
I am going to cut the lawn, takes 3 to 4 hours but I will be back later.