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Balljoint swap with front rack?

Posted By: SLOW67

Balljoint swap with front rack? - 03/20/11 04:36 AM

Looking to cut up a stock k member I've got laying around and add a front mounted rack and do some lightening. everyone says if you swap spindles side to side it will throw the steering axis off....but what if you just swapped ball joints and installed the rack so it is at the same angle as it would be in a rear steer configuration? I'm having trouble understanding why it wouldn't work if your rack angle is the same as the original rear steer Maybe I haven't had it simplified enough lol
Posted By: SLOW67

Re: Balljoint swap with front rack? - 03/20/11 10:11 PM

Guess I'll just try it and see
Posted By: B G Racing

Re: Balljoint swap with front rack? - 03/20/11 10:13 PM

It's been done a thousand times the big issue occurrs when backing up.
Posted By: LA360

Re: Balljoint swap with front rack? - 03/20/11 10:16 PM

Your ackerman angle will be incorrect if you swap ball joints over from one side to the other. Put simply, there should be a straight line between the steering arm, ball joint and the centre of the rear axle on both sides. If you are having trouble visualizing that, I suggest a search on Google, as there are many articles online available. On top of that you then have Bump steer to worry about, but that is more concerned with the tie rod length, position of the steering rack etc.
Posted By: SLOW67

Re: Balljoint swap with front rack? - 03/20/11 10:17 PM

So what happens? Every body I've asked says it causes "problems" but is never specific about what it does
Posted By: LA360

Re: Balljoint swap with front rack? - 03/20/11 10:19 PM

Your car will not steer correctly if it's not correct, here is some reading for you.
http://en.wikipedia.org/wiki/Ackermann_steering_geometry
Posted By: B G Racing

Re: Balljoint swap with front rack? - 03/20/11 10:19 PM

Many either heated and bent the steering bar part of the ball joint or cut and welded to correct it.Many old Pro Stockers did this.I won't When I seen the issues when backing up I called many chassis builders and they said "some do it more than others,just don't back up"
Posted By: Sport440

Re: Balljoint swap with front rack? - 03/20/11 10:49 PM

Like LA360,s link shows, your ackerman will be reversed. You will need to bend the steering arms out past the center to correct it. Extend the imaginary line from the center of the axel past the front of the balljoint for its correct location.

Its best to use the correct side balljoint/steering arm and just make your own font steering arm. You can leave the original steering arm hang out the back in its original location or you can cut it off.

Further the rack wants to be further back then the inside of the kframe will allow. So you need to modify the kframe to allow for that or fab a draglink type set up off the racks ends and make new inner mount tierod mounts that will position the tierods further back.
Posted By: MR_P_BODY

Re: Balljoint swap with front rack? - 03/20/11 11:32 PM

Quote:

So what happens? Every body I've asked says it causes "problems" but is never specific about what it does



Part of your issue will be the rack itself... you need
the inner tie rod end(end of the rack) to be AT the
same place as the lower control arm inner pivot point
(where the T bar is)... that way the tie rod will end
up being the same length as the lower control arm
BUT your K-member is in the way and you need to get
full travel on the spindle... you could change(build)
a new upper A-arm the same length as the lower BUT
look where that point would be... not good
Posted By: SLOW67

Re: Balljoint swap with front rack? - 03/20/11 11:57 PM

So using this theory my custom steering arms should sit outward closer to the wheel and tire to maintain the relationship with the rear axle/balljoint centerline correct? How much of a deviation from this line would be acceptable? On the rack mounting, rule of thumb is 3in from the rack centerline to the steering arm centerline correct?
Posted By: MR_P_BODY

Re: Balljoint swap with front rack? - 03/21/11 12:19 AM

Quote:

So using this theory my custom steering arms should sit outward closer to the wheel and tire to maintain the relationship with the rear axle/balljoint centerline correct? How much of a deviation from this line would be acceptable? On the rack mounting, rule of thumb is 3in from the rack centerline to the steering arm centerline correct?



The end of the steering are(outer tie rod end) you
will have in line with the centerline of the lower
ball joint.... that 3" on the tie rod end will work
in a drag car(but it will still scuff on the turns)
but you would like it straight
Posted By: SLOW67

Re: Balljoint swap with front rack? - 03/21/11 12:54 AM

So this will owrk then? (see attachment) the cardboard is a mock up of the steering arm. The first pic is just general to show the setup the second is a view from the top of the spindle with both balljoint holes lined up...

Attached picture 6540634-IMG00116-20110320-1947.jpg
Posted By: SLOW67

Re: Balljoint swap with front rack? - 03/21/11 12:54 AM

second...

Attached picture 6540637-IMG00117-20110320-1948.jpg
Posted By: MR_P_BODY

Re: Balljoint swap with front rack? - 03/21/11 01:04 AM

Quote:

So this will owrk then? (see attachment) the cardboard is a mock up of the steering arm. The first pic is just general to show the setup the second is a view from the top of the spindle with both balljoint holes lined up...



I assume its in line with the ball joint.... you
can raise that point IF needed so its on the same
plane as the rack
Posted By: SLOW67

Re: Balljoint swap with front rack? - 03/21/11 01:12 AM

When its all held up its inline with the balljoint...carboard is hard to work with lol. I just want my angles to be right because this is mostly a street car Thanks for all the help guys oh btw MR_P_BODY I've been following your front suspension build and its giving me all these bad ideas lol keep up the great work
Posted By: gregsdart

Re: Balljoint swap with front rack? - 03/21/11 01:19 AM

The best thing you can do is take measurements of the locations of the inner an d outer tie rod ends from the stock setup. This will provide you with a very good base point for properly locating the position of the new ends. Also you need to look at the length of the steering arms that were used with the rack in its original configuration. I had to shorten mine considerably. They are now half as long as before. Ignore the bad ackerman in my deal, it works OK on the track only.
To learn all about setting this deal up properly, there is a chapter in the chassis manual (or was) that describes bump steer and how to corect it, along with other info.

Attached picture 6540683-dartpics007.jpg
Posted By: MR_P_BODY

Re: Balljoint swap with front rack? - 03/21/11 01:30 AM

Quote:

When its all held up its inline with the balljoint...carboard is hard to work with lol. I just want my angles to be right because this is mostly a street car Thanks for all the help guys oh btw MR_P_BODY I've been following your front suspension build and its giving me all these bad ideas lol keep up the great work



I got mine all squared away... I have about 1" of off set,
I can live with that... not perfect but Ok.
You MAIN issue will be using a upper control arm...
being that its shorter than the lower... as the spindle
drops down the upper edge will swing in quicker and
cause your toe to go out... NOT GOOD.... unless you
can some how get the rack and tie rod at the same
point as the lower ball joint(both height and length)
so they pivot on the same arc as the lower arm does...
what I'm trying to say is the rack needs to be at the
lower control arm inner pivot point and the outter
tie rod needs to be at the ball joint height and be
on that same center line.... pretty much impossible
with the wheel and tire in the way
Posted By: gregsdart

Re: Balljoint swap with front rack? - 03/21/11 01:35 AM

Quote:

Quote:

When its all held up its inline with the balljoint...carboard is hard to work with lol. I just want my angles to be right because this is mostly a street car Thanks for all the help guys oh btw MR_P_BODY I've been following your front suspension build and its giving me all these bad ideas lol keep up the great work



I got mine all squared away... I have about 1" of off set,
I can live with that... not perfect but Ok.
You MAIN issue will be using a upper control arm...
being that its shorter than the lower... as the spindle
drops down the upper edge will swing in quicker and
cause your toe to go out... NOT GOOD.... unless you
can some how get the rack and tie rod at the same
point as the lower ball joint(both height and length)
so they pivot on the same arc as the lower arm does...
what I'm trying to say is the rack needs to be at the
lower control arm inner pivot point and the outter
tie rod needs to be at the ball joint height and be
on that same center line.... pretty much impossible
with the wheel and tire in the way



Mike, I think there is enough room with a short arm, which he needs anyway. I have enough on mine to get it right, but I have reasons for not going that way. This will only work with disc brakes.
Posted By: MR_P_BODY

Re: Balljoint swap with front rack? - 03/21/11 01:45 AM

Mike, I think there is enough room with a short arm, which he needs anyway. I have enough on mine to get it right, but I have reasons for not going that way. This will only work with disc brakes.



Yea I see you have enough room with dic and skinny
fronts
Posted By: dvw

Re: Balljoint swap with front rack? - 03/21/11 02:15 AM

Quote:

So what happens? Every body I've asked says it causes "problems" but is never specific about what it does


There are 2 issues. First is Ackerman. The purpose of Ackerman is to allow the inner wheel to turn in a tighter radius than the outer wheel. Think about a tight turn. The turning radius of the inner wheel could be half of the outer. By swapping the ball joints/steering arms the inner tire will turn in a larger radius than the outer causing tire scrub. It will cause toe in when turning,not good. The second issue is bump steer. Simple to figure out. Looking from the front of the car 4 points need to form a parallelogram. The inner tie rod,outer tie rod,lower control arm pivot,lower ball joint. Move the steering arm in the correct location and all will be OK. If not it'll drive like crap.
Doug
Posted By: Sport440

Re: Balljoint swap with front rack? - 03/21/11 02:50 AM

Quote:

So using this theory my custom steering arms should sit outward closer to the wheel and tire to maintain the relationship with the rear axle/balljoint centerline correct? How much of a deviation from this line would be acceptable?













Racers have raced with the steering arms reversed, with Reverse ackerman and its been acceptable in the past for race cars.

But IMO thats old school and no longer acceptable.
Ive done it and it is flat out unacceptable IMO.

In a perfect setup the ackerman is 100% correct and the steering tierods and lower control arms are parralel and the same exact length.

But you cant always do that, and they dont have to be. Another helpfull link is the Longacre web sight.

www.longacreracing.com/articles/art.asp?ARTID=13

It helps with Bump steer.

The two biggest problems with mounting a rack, are addressing "Bumpsteer and Ackerman"

You have the Ackerman figured out, Your next issue will be bumpsteer. Thats not so easy to address. Since your working with imaginary lines it will be more of a trial and error education.

For a Race car, Many will overlook those problem issues of a Rack swap. As long as it goes Straight fine, Whats the problem.

I did the internal Kframe rack swap back in 96 based on a article from "Chuck Senotore" Let me tell you, Thats a Race deal only!





Posted By: SG duster

Re: Balljoint swap with front rack? - 03/21/11 07:40 AM

Quote:

everyone says if you swap spindles side to side

WHAT?? Iv never herd that one, ball joints yes but spindles no way!!
Posted By: sixpackgut

Re: Balljoint swap with front rack? - 03/21/11 08:34 PM

here is a picture of what i did over the winter on my wall car. K frame weight went from i think 31# to 19#. manual gear box was 16# to a rack 10# i think these weights are right. plus i didnt even weigh the arms, drag link and other stuff. IDK if it will work yet though

Attached picture 6541944-179327_1630432553137_1006291331_31377492_612074_n.jpg
Posted By: SLOW67

Re: Balljoint swap with front rack? - 03/21/11 11:24 PM

Did you build your own steering arms? I'd like to see more pics if you dont mind...might get some ideas
Posted By: Dos Snails

Re: Balljoint swap with front rack? - 03/22/11 01:16 AM

Quote:

here is a picture of what i did over the winter on my wall car. K frame weight went from i think 31# to 19#. manual gear box was 16# to a rack 10# i think these weights are right. plus i didnt even weigh the arms, drag link and other stuff. IDK if it will work yet though

I'm no expert but I'm going to say that rack will give you bump steer.. It has to long of a body which puts the inner tie rods outside of the inner pivot points.I just spent a quite bit of time studying suspensions before I started making a C5 front suspension cross member for my Challenger..
Posted By: sixpackgut

Re: Balljoint swap with front rack? - 03/22/11 01:36 AM

Quote:

Did you build your own steering arms? I'd like to see more pics if you dont mind...might get some ideas



no,got them from a member here

Attached picture 6542451-032101_2020[00].jpg
Posted By: AAR-B4

Re: Balljoint swap with front rack? - 03/22/11 02:21 AM

Made my own. Pics tell the story.


Posted By: rowin4

Re: Balljoint swap with front rack? - 03/22/11 04:08 AM

Take a look at what I found on E-Bay Motors, Item #160537404813 enlarge and look for the rack pictures. looks like some thing that could be done easily by modifying the stock k- member

Posted By: SLOW67

Re: Balljoint swap with front rack? - 03/22/11 04:31 AM

Quote:

Made my own. Pics tell the story.






Thats real close to my cardboard mock up I made....mine will be alittle higher though to make the rack in line with the LCA at rest. I'm going to measure acouple racks this week to get an idea of which one I can use to get my inner tie rod on the rack even with the LCA pivot
Posted By: HEMIFRED

Re: Balljoint swap with front rack? - 03/22/11 04:48 AM

excluding the coil overs all the front suspension parts on my Duster except the rack are factory. The spindels are kelsey disc units the only ones that will accept the bolt pattern letting B body lower ball joint arms on and reversed. Only nneeded to be slightly bent.Stock upper and lower A arms . upper arms swapped side to side for more caster
this is the untouched spindel


one trimmed for weight loss



here's all the front suspension pics

http://s9.photobucket.com/albums/a65/HEMIFRED/DUSTER%20SUSPENSION/?start=all
Posted By: SLOW67

Re: Balljoint swap with front rack? - 03/22/11 04:55 AM

What rack did you use?
Posted By: HEMIFRED

Re: Balljoint swap with front rack? - 03/22/11 07:04 AM

Quote:

What rack did you use?



I didn't build the front it was done by Sox & Martin's shop. PINTO rack
Posted By: sixpackgut

Re: Balljoint swap with front rack? - 03/22/11 03:38 PM

Quote:

What rack did you use?



i bought a pinto rack for mine off ebay for about $100. the arms i got off a member for $100 and i bought a tie rod kit from S&W for i believe $45. i would have had to rebuild the whole front steering anyway so i think it was probably a wash on cost. bet i lost over 25 lbs off the front also
Posted By: SLOW67

Re: Balljoint swap with front rack? - 03/22/11 05:50 PM

I'm looking to get all the steering stuff out of the way for a future BB swap plus loose some weight in the process. I also plan on going to coilovers too when I can afford it. I figure if I spent the time and money to replace the sloppy steering box I could already have had this setup built in my parts car and just swap it all over
Posted By: Sport440

Re: Balljoint swap with front rack? - 03/22/11 10:43 PM

Quote:

Quote:

What rack did you use?



i bought a pinto rack for mine off ebay for about $100. the arms i got off a member for $100 and i bought a tie rod kit from S&W for i believe $45. i would have had to rebuild the whole front steering anyway so i think it was probably a wash on cost. bet i lost over 25 lbs off the front also





Dont forget you will need some type of coupler shaft from the rack to the steering wheel shaft. I used two borgesion joints and a 3/4 splined shaft. I think in 96 the joints were $40 apiece and the shaft $20+ or so. And a 3/4" heim joint to tie it to the fenderwell. $20 bucks new or $5 swap meet. I think my swap was around $360 total, plus Lots of labor.

I fabbed it in 3 different times.

Once with the ball joints/steering arms flipped.
Once with the ball joints correct and fabbed steering arms.

And once with the K modified more like yours to get the Rack Back as far as it could go, right against the BB oil pan front wall.

And now with my new oil pan Im even considering moving it back more for a forth refab.

I guess I dont like to do things once.
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