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Bump Steer Kit Questions?

3K views 13 replies 3 participants last post by  Mutt's37Buick 
#1 ·
I need to shorten the steering arm length on my '95 Roadmaster spindles.
1) Has anyone out there used this bump steer kit on a Mustang, and did it work well?
2) Is there a less expensive kit out there (found it for $265 on ebay)?
3) Does anyone know of such a kit for other cars?
Thanks
 

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#2 ·
from scratch

I Think you are building your suspension. The kits I saw moved the locations of the rack or pivot points at the steering arms. In the Wiki on using a caviliar in an early GM suspension upgrade the writer moved the location and angles of the rack to fine tune it. Can you lock a brake rotor, have the suspension with out springs and shocks. Fasten a laser pointer to the rotor then move the suspension and rack around and watch the dot. watch camber change, castor change. toe change etc An old Ford buddy, Bruce Cambern, retired head of Ford racing. has done a lot of suspension work on his 66 Cobra, 2009 Optima winner, and some Cad analysis. It just takes longer doing it with the car.
 
#3 ·
I'm actually not concerned with bump steer at the moment.
I'm planning on using the cavalier r&p like in the wiki and I think we will be able to minimize bump steer that by adjusting the rack position.
I'll try your suggestion at that point.
What I'm currently concerned with is the length of the steer arms.
In the wiki, the author "oldguy829" used 5.5" long steer arms attached to CPP drop spindles. I'm using '95 Roadmaster spindles with 6.4" effective control arms. With my current controls arms, my turn radius will be large. I hoped to use something like the mustang bump steer kit to shorten my turn radius and make steering quicker.
 
#4 ·
bump steer kit

The Mustang 5.0 bump steer kit is used a lot on autocross cars. with the Fox strut suspension, changing to progressive rate lowering springs changes the geometry. Normally with a Double A arm suspension you want the lower A arm parallel to the ground at ride height and the tie rod also parallel. A lot of autocross cars run a de-cambered front end with the top of the tires pointed in, and have some toe out during turns. and If the car is street driven you want predictible handling, Nothing is scarrier than going into a hard corner fast and having the car going from under steer to oversteer. having a mind of it's own. Heidt's IFS web site used to have 4 or 5 pages of suspension design information.the new owners changed the site but I found it again last year. things to think about. sometimes you can go to google books and "preview" some of the books on suspension design, building hot rods , race cars etc. some you can read the whole book on the previews, others nothing, Since you are building your front suspension from various pieces you can try to get mounting locations, pivot points, etc, right and not use the Mustang kit. and not have oil pan interference.
 
#5 ·
quick steer rack

I don't know if there is a quick steer rack, from sports handling package that will work for you. The First T bucket I built in the 50's had a 6 turn steering gear, so I made all the pieces to use all 6 turns. I got it going and did the first burn out. I couldn't turn the steering wheel fast enough, I was out in a field, no damage, just an education.
 
#7 ·
As problem is that my spindles are set up for a 7" throw side to side.
1) Making a conversion parts like the Mustang Bump steer would shorten the steer arm by 1" and allow me to use a Cavalier r&P with 6" throw.
Othe options I'm considering are:
2) Use the GM gearbox that came from the 95 Roadmaster and shorten the center link so that the tie rods connections are in line with lower control arm pivot. Advantages: Uses more of steer system I already have and cut and sleeve cross link simple modification. Disadvantage: End up with looser steering typical of '95 Roadmaster and future replacement of gearbox would be costly.
3) Take a 7" side to side R&P with end take off and convert it to center take off with a cross member like attached picture. Advantage: End up with tighter steering because or R&P and R&P replacement lower cost in future. Disavantage: Have not found anyone who has done this, but think would be possible.
What do you experts on car building think would be best path?
Thanks
 
#8 ·
A couple alternatives here. I have shortened steering arms by cutting and rewelding, done by a certified welder. Some of these cars have seen over 100,000 miles with no problems. I have also done this by building up the steering arm with weld, and redrilling the arm closer to the king pin axis.

Alternatively, you could use a 94 to 97 Jeep Cherokee steering box, a 12 to 1 quick ratio, and a functional bolt in replacement for the Roadmaster box. They are usually $50 at a salvage yard.
 
#10 ·
more ideas

CCP has a new rack. Go to the Hotrodhotline site then scroll down to new product reviews and on down to the
CCP ad , they have a center link with the added center bar and the wider pivot points for early chevelles. A lot of steering systems used the same castings. The supplier sent in a crate of big mercury steering gears to the Ford truck assembly plant every thing bolted up. the internals were opposite. At the end of the assembly line the driver had to make a sharp turn to the wheel dynamometer and headlight aim. The truck made a hard left an almost took out the seat builder crew. Plymouth cars and dodge pickup shared the same castings with reversed internals.
 
#12 · (Edited)
No idea ?

I read a while back you were checking out R & P steering systems I have no idea of the ratio , travel or dimensions of the pivot points, but It Is pricey, similar to the 65 Mustang one I saw. CCp should be able to provide that info. I look at a lot of stuff out there and usually copy-fab my own pieces.
 
#14 ·
Checked with Classic Performance Products and the Chevell Rack & Pinion has 6" side to throw and tech believed it was based on the Cavalier R&P.
Fatman also has a bracket kit that works with a Cavalier R&P and is set up for a '37 Buick and costs $225 (plus cost opf r&p). They're sending me instructions so I can see what the brackets look like.
Still same issue that 6" throw will increase my turn radius.
The other option that is out there is the Retrorack from Australia.
Has center take off and a side to side throw of over 8", but at a cost of over $3K it is not in my budget.
Without any examples that my 3) below has been done I'm leaning towards either:
1) Welding on a part similar to the bump steer mustang kit that will shorten the steer arm and using a Cavalier R&P, or
2) Use GM gearbox with modified center link.
I know this is a matter of opinion, but can the GM gearbox be set up to steer as well as a the rack & pinion?
Thanks
 

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