Moparts
Front Steer Rack Conversion - Part Deux - UPDATE!!
Posted By: STEFF
Front Steer Rack Conversion - Part Deux - UPDATE!! - 02/16/14 02:22 AM
Posted By: RV2
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 02:47 AM
Nice!
Posted By: Stanton
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 02:54 AM
That's impressive. Now, will it clear an oilpan ???
Posted By: LSP
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 03:04 AM
Wow, nice work Steff!
Posted By: ta3834bbl
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 03:37 AM
I bet it will fit with a 6 qt truck rear sump oil pan just fine ???
Posted By: MR_P_BODY
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 03:47 AM
Looks real good Steff... nice and strong... where will
the arms mount.. are you staying with double arms
or going strut
EDIT
Never mind.. I see the tube
Posted By: SpareParts
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 03:50 AM
Looks good. I was just thinking about doing this today. What front suspension??
Posted By: jcc
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 04:10 AM
You know what I find most commendable, you took the criticism in Part 1, you studied it, you didn't make excuses, you got back on the horse, and you made it better. not many would/could do that.
Posted By: Ohio Joe
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 04:16 AM
Very very nice looking , wish I were as talented.
Posted By: Dragula
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 05:38 AM
Wish I had half yur talent...Looks awesome. And the best part is, you built it.
Posted By: Stanton
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 05:54 AM
So, what do you use for front lower ball joints?
Posted By: Sport440
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 07:18 AM
Quote:
You know what I find most commendable, you took the criticism in Part 1, you studied it, you didn't make excuses, you got back on the horse, and you made it better. not many would/could do that.
I dont know, Still looks very weak to me. She will probably bust on its first outing. 
Posted By: JERICOGTX
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 02:46 PM
How are you mounting the strut arms?
Jeff
Posted By: DusterDave
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 03:11 PM
Looks good, STEFF. Did you build a jig first, or did you tack everything together under the car? I assume you modeled it out first, to get all your cut lengths and angles?
Posted By: gregsdart
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 04:25 PM
Class work there! Looks to be stout enough to take all the stress you could ever throw at it, including road racing.
Posted By: 340B5
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 04:31 PM
Bulletproof for sure.
Posted By: Quicktree
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 04:53 PM
sure looks nice but how heavy is it? CM or mild steel?
Posted By: ProSport
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 05:20 PM
That looks good Steff!
Posted By: pittsburghracer
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 05:45 PM
Quote:
That looks good Steff!
Posted By: Anonymous
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 06:40 PM
It does look good but I see a weak link. With the way forces come into play the top 2x3 and the down leg 2x3 tubes welded joint, I think you would need a gusset. When I did my frame rails I cut the sides and inside face of the angle and then folded it in so the outside face stayed as one continuos piece and welding was only required on three sides. I really like this piece though as I want to give this a go for my car but ended up buying an Alterkation unit.
Posted By: jcc
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 07:23 PM
IMO, yes and no, In the area a gusset is suggested I don't see a stress concentration, relative to the rest of his design, and therefore adding a gusset would only make another area more prone to flexing and stress concentration issues, it looks to me well balanced in this concern, sure he could add stuff all over it, with the added weight. Bottom line much better execution. I would like to know however how beefy his mounting holes are 3" sides on the 2x3's.
Posted By: sshemi
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 07:49 PM
Anyone saying that its not strong enough better start with Lego or something other than cars!
Posted By: Stanton
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 11:20 PM
If he used a washer on his bolts they'd be as beefy as any stock k-member! Hell, those things are only two layers of sheetmetal !!
Posted By: Stanton
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 11:25 PM
How does this thing compare height-wise to a stock k-member. Judging by the position of the strut mounts relative to the bottom it looks like it would hang a couple inched lower than a stock k-member.
Posted By: 1967dartgt
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 11:39 PM
What does it weight? What control arms are you going to use?
Posted By: STEFF
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 11:46 PM
Thanx all for the positive feedback! It's much appreciated! Here's the answers to a bunch of the questions.
I designed the k-frame in Solidworks 3D software. It was designed to use the stock lower control arms and strut rod arrangement with a strut rod using a heim end at the front. I plan to get rid of the t-bars and go to coilovers, once I get the shock area reinforced. All of the round tubing is 4130 moly: 1 1/2 dia x .120 wall for the 3 main tubes and 1" x .083 wall for all of the other pieces. Rect. tubing is 2 x 3 x 1/8 wall mild steel and Sq. tubing is 2" x 1/8 wall mild steel. Mounting holes are reinforced with Grade 8, 1/2 flat washers, that are 1 3/4 dia. by about an 1/8" thick.
I built it on a jig. This is one of the only build pic I have.
Weight is 28 lbs bare. I wanted to make sure this thing could handle a pot hole as it is going on a street/strip car. So a few extra pounds wasn't a big deal. It's still alot lighter than the stock frame. I think the stock k-frame was around 40 lbs.
And for reference, the Pinto Rack weighs 12 lbs. A stock manual gear box with the steering arm, drag link, tie rod ends, and idler arm weighs 28 lbs. So, 40 lbs for the new K-frame and rack vs. 68 lbs for the stock stuff.
I got it into the car and it's fits like a glove. I'm really pleased. Here are a few pics of it installed.
Posted By: STEFF
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 11:54 PM
Quote:
How does this thing compare height-wise to a stock k-member. Judging by the position of the strut mounts relative to the bottom it looks like it would hang a couple inched lower than a stock k-member.
Stock K-frame from mtg. face to bottom is 7". My new K-frame from mtg. face to bottom is 7 3/16", so, 3/16 difference. The lower control arm location and strut rod intersect point at front (centerline of bolt for heim) is in the stock location.
Posted By: jcc
Re: Front Steer Rack Conversion - Part Deux - 02/16/14 11:56 PM
Quote:
If he used a washer on his bolts they'd be as beefy as any stock k-member! Hell, those things are only two layers of sheetmetal !!
I strongly disagree. They are not an open span of 2.75"of 1/8" sheetmetal like the OP's. They are closely gusseted as possible, and welded, granted not well. I think the OP at least, for all his other efforts here, should insure this bolted conection, almost the most single point that chassis forces are channeled thru, does not flex. I will later post a close up of the OEM area, but am sure most are familiar with it anyway. 
Posted By: Thumperdart
Re: Front Steer Rack Conversion - Part Deux - 02/17/14 12:01 AM
As others have stated, great job and looks plenty stout but I`m no engineer. I too admire guys like you and wish I had your fab skills................
Posted By: mshred
Re: Front Steer Rack Conversion - Part Deux - 02/17/14 12:27 AM
Just awesome Stef! That is sweeeet!
Posted By: 1967dartgt
Re: Front Steer Rack Conversion - Part Deux - 02/17/14 01:16 AM
Looks good, why the heim joint on the steering shaft?
Posted By: Stanton
Re: Front Steer Rack Conversion - Part Deux - 02/17/14 01:35 AM
What body style is that built for, a or b/e ?
Post more pics when its all hooked up please.
Posted By: 1967dartgt
Re: Front Steer Rack Conversion - Part Deux - 02/17/14 01:51 AM
I didn't need one
Posted By: STEFF
Re: Front Steer Rack Conversion - Part Deux - 02/17/14 02:17 AM
Quote:
Looks good, why the heim joint on the steering shaft?
The inner steering g shaft isn't supported, coming out of the column. It was either make a bushing to insert into the end of the column or add a Heim. I opted for the heim.
Posted By: STEFF
Re: Front Steer Rack Conversion - Part Deux - 02/17/14 03:11 AM
Quote:
What body style is that built for, a or b/e ?
Post more pics when its all hooked up please.
Built for my 70 Road Runner.
Posted By: MR_P_BODY
Re: Front Steer Rack Conversion - Part Deux - 02/17/14 03:23 AM
Looks real nice Steff... fits in there nice also
Posted By: jcc
Re: Front Steer Rack Conversion - Part Deux - 02/17/14 05:14 AM
My recollection is flawed. I have been lately working on my RMS K, and it has a 1.75 opening in K member attaching bolt tube. Below is a 2x3tube next to I believe a typical OEM K. The opening measurers 2.72" in rear and 2.39" in front. OP's front with 2" sq tube is a smaller area. However very importantly there is on all attaching bolt areas a third vertical gusset, 1" from bolt hole center on the third side, and provides most of the mounting surface reinforcement. The pictured OEM flange thickness is .285", with dirt/rust.
Posted By: 1967dartgt
Re: Front Steer Rack Conversion - Part Deux - 02/17/14 04:04 PM
Quote:
My recollection is flawed. I have been lately working on my RMS K, and it has a 1.75 opening in K member attaching bolt tube. Below is a 2x3tube next to I believe a typical OEM K. The opening measurers 2.72" in rear and 2.39" in front. OP's front with 2" sq tube is a smaller area. However very importantly there is on all attaching bolt areas a third vertical gusset, 1" from bolt hole center on the third side, and provides most of the mounting surface reinforcement. The pictured OEM flange thickness is .285", with dirt/rust.
So a factory is a little more then twice as thick in mounting flange then a 1/8 box tube.
Posted By: hemicop
Re: Front Steer Rack Conversion - Part Deux - 02/17/14 04:39 PM
I like it! So here's a question...........
Do you plan on making & selling these for A-bodies using using coilovers & retaining the stock, or stock-type LCA?
Posted By: STEFF
Re: Front Steer Rack Conversion - Part Deux - 02/17/14 04:54 PM
Quote:
Quote:
My recollection is flawed. I have been lately working on my RMS K, and it has a 1.75 opening in K member attaching bolt tube. Below is a 2x3tube next to I believe a typical OEM K. The opening measurers 2.72" in rear and 2.39" in front. OP's front with 2" sq tube is a smaller area. However very importantly there is on all attaching bolt areas a third vertical gusset, 1" from bolt hole center on the third side, and provides most of the mounting surface reinforcement. The pictured OEM flange thickness is .285", with dirt/rust.
So a factory is a little more then twice as thick in mounting flange then a 1/8 box tube.
There is an extra L-shaped piece welded in the hole area. The total of the main plate thickness and extra L-shaped piece make up the approx 1/4" thickness.
Posted By: STEFF
Re: Front Steer Rack Conversion - Part Deux - 02/17/14 05:23 PM
Quote:
I like it! So here's a question...........
Do you plan on making & selling these for A-bodies using using coilovers & retaining the stock, or stock-type LCA?
I don't know that I will. There's plenty of aftermarket suspensions on the market already.
Posted By: dartman366
Re: Front Steer Rack Conversion - Part Deux - 02/17/14 05:28 PM
good looking work Steff, I like it.
Posted By: Stanton
Re: Front Steer Rack Conversion - Part Deux - 02/17/14 06:57 PM
From the looks of the steering linkage a stock motor mount would pretty much be out of the question, correct?
Still wondering what you're using for front lower ball joints/steering arms ???
Posted By: sixpackgut
Re: Front Steer Rack Conversion - Part Deux - 02/17/14 08:44 PM
Steff, beautiful work as always but I thought the intent of the rack was to use an oil pan that wasn't so deep and now it looks like the whole front k frame is just about as deep as the pan
Posted By: jcc
Re: Front Steer Rack Conversion - Part Deux - 02/17/14 08:51 PM
A number replies back a member suggested gusseting the tube angle welds. I was not a proponent of that solution. However for argument's sake, RMS originally used a similar welded non gusseted tube design, and then later changed to a bent square tube, with no intermediate welds. Never heard their reason for the change. The RMs was a 2" sq tube FWIW.
Posted By: Bubba
Re: Front Steer Rack Conversion - Part Deux - 02/17/14 09:04 PM
nice.
Posted By: STEFF
Re: Front Steer Rack Conversion - Part Deux - 02/17/14 09:08 PM
Quote:
Steff, beautiful work as always but I thought the intent of the rack was to use an oil pan that wasn't so deep and now it looks like the whole front k frame is just about as deep as the pan
The intent was to rid of the drag link going thru the oil pan and reduce the depth of the pan. The new k-frame hangs only 3/16" of an inch lower than the stock k-frame: stock = 7" vs mine = 7 3/16". The rack location dictated the depth. Without the drag link, I can now make the pan shorter in depth.
Posted By: Stanton
Re: Front Steer Rack Conversion - Part Deux - 02/17/14 09:51 PM
Quote:
A number replies back a member suggested gusseting the tube angle welds. I was not a proponent of that solution. However for argument's sake, RMS originally used a similar welded non gusseted tube design, and then later changed to a bent square tube, with no intermediate welds. Never heard their reason for the change. The RMs was a 2" sq tube FWIW.
I would imagine that once into production they would either bend or have those tubes bent simply to save the labor of angle cutting and welding. Given that a bent 2" square tube would end up with a very thin wall on the long radius I suspect there would be less strength in a bent piece than a properly welded piece.
They may also have done it for "appearance" and in this case they may have used bent flats for the top and bottoms, laser-cut sides and then welded all the seams. This is very common in the hotrod frame industry.
Posted By: sixpackgut
Re: Front Steer Rack Conversion - Part Deux - 02/17/14 09:53 PM
Quote:
Quote:
Steff, beautiful work as always but I thought the intent of the rack was to use an oil pan that wasn't so deep and now it looks like the whole front k frame is just about as deep as the pan
The intent was to rid of the drag link going thru the oil pan and reduce the depth of the pan. The new k-frame hangs only 3/16" of an inch lower than the stock k-frame: stock = 7" vs mine = 7 3/16". The rack location dictated the depth. Without the drag link, I can now make the pan shorter in depth.
oh wow, looks a lot deeper. very nice
Posted By: Plumb Wired
Re: Front Steer Rack Conversion - Part Deux - 02/18/14 02:23 PM
Nice work Steff!
Mike Gray
Posted By: OUTLAWD
Re: Front Steer Rack Conversion - Part Deux - 02/19/14 03:43 AM
Looks great! I may toy around with something similar one of these days...
Posted By: cl440
Re: Front Steer Rack Conversion - Part Deux - 02/20/14 09:52 PM
We had to reinforce our aftermarket unit after it broke. Its been fine ever since. Very similar to yours but yours looks even heavier duty. Very nice!
Posted By: jcc
Re: Front Steer Rack Conversion - Part Deux - 02/20/14 10:06 PM
Where did it break?
Looking closer at the attachment it "looks" like 6 1" tube braces were added?
Posted By: Stanton
Re: Front Steer Rack Conversion - Part Deux - 02/20/14 11:37 PM
Seems to me there's an opportunity here to easily solve the stock caster issues by moving the LCA mount slightly forward. With the stock K guys try to correct it by pulling the LCA forward with the struts which would seem to me to cause binding at the pivot. A solution would be to move the LCA mount forward, shorten the tube by 1/2" and make up that difference with spacers on either the front or back to get the desired caster. Just a thought ...
Posted By: cl440
Re: Front Steer Rack Conversion - Part Deux - 02/21/14 06:08 AM
Quote:
Where did it break?
Looking closer at the attachment it "looks" like 6 1" tube braces were added?
Right side tube that runs front to back and has the dip in it to clear the rack. You can see the paint was ground away to weld the area.
Posted By: cl440
Re: Front Steer Rack Conversion - Part Deux - 02/21/14 06:10 AM
Yes 6 tubes were added
Posted By: jcc
Re: Front Steer Rack Conversion - Part Deux - 02/21/14 11:25 PM
Good choice
Posted By: STEFF
Re: Front Steer Rack Conversion - Part Deux - 02/22/14 01:33 AM
Chuck, I'm curious, what do your steering arms look like?
Posted By: cl440
Re: Front Steer Rack Conversion - Part Deux - 02/22/14 02:40 AM
I will see what I have for pics? Car is at chassis shop getting tubs and frame rails or I would run out and take a pic for ya.
Posted By: Stanton
Re: Front Steer Rack Conversion - Part Deux - 03/03/14 05:22 AM
Been asked before but not answered ... What lower ball joints will you be using to solve the ackerman issue? I had the opportunity to look closely at an assembled front end over the weekend and I don't think you can get the outer tierod end anywhere close to where it needs to be with stock spindles and rotors.
Posted By: 1967dartgt
Re: Front Steer Rack Conversion - Part Deux - 03/03/14 06:15 AM
Quote:
Been asked before but not answered ... What lower ball joints will you be using to solve the ackerman issue? I had the opportunity to look closely at an assembled front end over the weekend and I don't think you can get the outer tierod end anywhere close to where it needs to be with stock spindles and rotors.
How's this?
Posted By: 1967dartgt
Re: Front Steer Rack Conversion - Part Deux - 03/03/14 06:16 AM
Posted By: 1967dartgt
Re: Front Steer Rack Conversion - Part Deux - 03/03/14 06:19 AM
Welded together
Posted By: STEFF
Re: Front Steer Rack Conversion - Part Deux - 03/03/14 12:57 PM
Quote:
Been asked before but not answered ... What lower ball joints will you be using to solve the ackerman issue? I had the opportunity to look closely at an assembled front end over the weekend and I don't think you can get the outer tierod end anywhere close to where it needs to be with stock spindles and rotors.
I've got a lower steering arm designed and in process. I've got a 3D model of it I can post later today.
67DartGT, your front end looks really good! 
Posted By: Stanton
Re: Front Steer Rack Conversion - Part Deux - 03/03/14 03:52 PM
Great if you could post that.
Posted By: 1967dartgt
Re: Front Steer Rack Conversion - Part Deux - 03/03/14 03:58 PM
Quote:
Quote:
Been asked before but not answered ... What lower ball joints will you be using to solve the ackerman issue? I had the opportunity to look closely at an assembled front end over the weekend and I don't think you can get the outer tierod end anywhere close to where it needs to be with stock spindles and rotors.
I've got a lower steering arm designed and in process. I've got a 3D model of it I can post later today.
67DartGT, your front end looks really good!
Thanks. Its really Tory's front end, cant wait for this weather to break so I can try it out.
Posted By: STEFF
Re: Front Steer Rack Conversion - Part Deux - 03/03/14 07:37 PM
Posted By: STEFF
Re: Front Steer Rack Conversion - Part Deux - 03/03/14 07:53 PM
Posted By: HardcoreB
Re: Front Steer Rack Conversion - Part Deux - 03/04/14 03:11 AM
Looks good as always Steve.
You left here just in time, it's COLD and SNOWY!!!
Posted By: LA360
Re: Front Steer Rack Conversion - Part Deux - 03/04/14 12:26 PM
I'd like to know about the lower ball joints, a few people have used different types. I have seen some with bolt in units, but most have been screw in units (which I believe are B Body units???)
Posted By: STEFF
Re: Front Steer Rack Conversion - Part Deux - 03/04/14 01:08 PM
Quote:
I'd like to know about the lower ball joints, a few people have used different types. I have seen some with bolt in units, but most have been screw in units (which I believe are B Body units???)
Screw in ball joint #K772......same as upper. It had the same stud dimensions as the stock b-body lower ball joint.
Posted By: Stanton
Re: Front Steer Rack Conversion - Part Deux - 03/04/14 04:32 PM
For proper ackerman, the tie rod end should fall on a line drawn from the center of the rear axle through the front lower ball joint. Looking at a front end with stock spindles and discs, this just isn't possible.
Also (correct me if I'm wrong here) the idler arm pivots and center link pivots should also fall on a line drawn from the center of the rear axle through the LCA pivot point.
So with the front-mount rack, it would have to be wider at the inner tie rod ends than the LCA pivots - the actual width depending also on how far forward it is. Correct ?
I'm wondering if its possible to overcome the ackerman issue by moving the rack further forward.
Does anyone know of a book that has good info on front end design?
Posted By: jcc
Re: Front Steer Rack Conversion - Part Deux - 03/04/14 05:03 PM
Since you seem to be open to varying opinions:
1. So whatever forces the balljoint inputs upward, they are resisted first by the flat section surrounding the balljoint, which will flex, to what degree I don't know, and the bending forces will be also resisted by the two 5/8"? attaching bolts in single shear that mount to the spindle, correct? Seems Like thickening/adding a web/etc around the balljoint would stiffen this area, reducing the bending load.
2. Is this billet or welded?
3. The steering arm web is IMO way over kill, the way I see it the arm mainly needs to transfer steering inputs, which I also think most grossly over estimate, and resist the twisting induced by the bump steer standoff correction. Your large/long web is not the ideal solution for those two scenarios.
4. It looks nice.
Posted By: gregsdart
Re: Front Steer Rack Conversion - Part Deux - 03/04/14 07:03 PM
Quote:
For proper ackerman, the tie rod end should fall on a line drawn from the center of the rear axle through the front lower ball joint. Looking at a front end with stock spindles and discs, this just isn't possible.
Also (correct me if I'm wrong here) the idler arm pivots and center link pivots should also fall on a line drawn from the center of the rear axle through the LCA pivot point.
If you have to compromise bump steer, toe out at top and bottom is prefered, bacause it doesn't over steer the car in a hard turn with body roll. That dictates at least the proper length tie rods, or slightly longer.
So with the front-mount rack, it would have to be wider at the inner tie rod ends than the LCA pivots - the actual width depending also on how far forward it is. Correct ?
I'm wondering if its possible to overcome the ackerman issue by moving the rack further forward.
Does anyone know of a book that has good info on front end design?
The lower control arm arc at the ball joint sets the length of the tie rods, which in turn set the width of the rack. Moving it forward or back will not help, only mess up the angle of the tie rods. Bump steer is more important than Ackerman, provided Ackereman doesn't get too far out of whack for what you want to do with the car. I have zero in my race car, would never go less than half needed for the street.
If you have to compromise bump steer at all, it is better to toe out at top and bottom of travel. that way the car won't over steer in a hard turn with body roll.
That would be a situation where the tie rods need to be longer than perfect, and the rack would have to be shorter than is best. It doesn't take much to screw the whole deal up. I spent many hours on my street dart, getting down to as little as 1/8 inch change in tie rod length and up/down location before it looked good to me.
Posted By: Stanton
Re: Front Steer Rack Conversion - Part Deux - 03/04/14 07:30 PM
Quote:
The steering arm web is IMO way over kill
Good god, what are we talking, a couple ounces ?!?!? Hell, skip the fries at lunch !!!
As for the ackerman, zero is fine for straight line racing but the OP's application (as far as I know) and mine would be a street car and you do want some ackerman or you end up with significant scrub.
Posted By: STEFF
Re: Front Steer Rack Conversion - Part Deux - 03/04/14 08:10 PM
Quote:
Quote:
The steering arm web is IMO way over kill
Good god, what are we talking, a couple ounces ?!?!? Hell, skip the fries at lunch !!!
As for the ackerman, zero is fine for straight line racing but the OP's application (as far as I know) and mine would be a street car and you do want some ackerman or you end up with significant scrub.
As far as the ackerman discussion, from everything I read, if you get the outer tie rod intersect outside the balljoint, you will have ackerman. Maybe not the exact optimimum position, because of space limitations ie: the wheel, but you do the best you can. On a side note, My rack is out 8 1/2" in front of the wheel. The outer tie rod connection is 7" in front. My mind escapes me how far out the tie rod connect point is outside of the ball joint. I'll have to look at my notes. Also, using my test arms, I played around with the outer connect location, in and out, up and down and settled on a position that got bumpsteer to within .030" over 6" travel.
Posted By: TShell
Re: Front Steer Rack Conversion - Part Deux - 03/04/14 08:26 PM
Quote:
Quote:
Quote:
The steering arm web is IMO way over kill
Good god, what are we talking, a couple ounces ?!?!? Hell, skip the fries at lunch !!!
As for the ackerman, zero is fine for straight line racing but the OP's application (as far as I know) and mine would be a street car and you do want some ackerman or you end up with significant scrub.
As far as the ackerman discussion, from everything I read, if you get the outer tie rod intersect outside the balljoint, you will have ackerman. Maybe not the exact optimimum position, because of space limitations ie: the wheel, but you do the best you can. On a side note, My rack is out 8 1/2" in front of the wheel. The outer tie rod connection is 7" in front. My mind escapes me how far out the tie rod connect point is outside of the ball joint. I'll have to look at my notes. Also, using my test arms, I played around with the outer connect location, in and out, up and down and settled on a position that got bumpsteer to within .030" over 6" travel.
Posted By: jcc
Re: Front Steer Rack Conversion - Part Deux - 03/05/14 04:48 PM
Quote:
Quote:
The steering arm web is IMO way over kill
Good god, what are we talking, a couple ounces ?!?!? Hell, skip the fries at lunch !!!
As for the ackerman, zero is fine for straight line racing but the OP's application (as far as I know) and mine would be a street car and you do want some ackerman or you end up with significant scrub.
As much as I agree with the above on ackerman, defining the problem as "scrub" could be misleading, as scrub is more usually thought to be related to SAI type issues, although your point about lack of ackerman is still understood to be clearly negative.
And it doesn't take many fries to soon add up to a 1/4 pounder. 
http://en.wikipedia.org/wiki/Scrub_radius
Posted By: STEFF
Re: Front Steer Rack Conversion - Part Deux - 03/05/14 04:54 PM
Quote:
Quote:
Quote:
Quote:
The steering arm web is IMO way over kill
Good god, what are we talking, a couple ounces ?!?!? Hell, skip the fries at lunch !!!
As for the ackerman, zero is fine for straight line racing but the OP's application (as far as I know) and mine would be a street car and you do want some ackerman or you end up with significant scrub.
As far as the ackerman discussion, from everything I read, if you get the outer tie rod intersect outside the balljoint, you will have ackerman. Maybe not the exact optimimum position, because of space limitations ie: the wheel, but you do the best you can. On a side note, My rack is out 8 1/2" in front of the wheel. The outer tie rod connection is 7" in front. My mind escapes me how far out the tie rod connect point is outside of the ball joint. I'll have to look at my notes. Also, using my test arms, I played around with the outer connect location, in and out, up and down and settled on a position that got bumpsteer to within .030" over 6" travel.
Tshell, Tried to PM you back, but you have that feature set to not accept PM's.
But, Thanx for kind words!
Posted By: 1967dartgt
Re: Front Steer Rack Conversion - Part Deux - 03/05/14 05:07 PM
Quote:
Quote:
Quote:
Quote:
Quote:
The steering arm web is IMO way over kill
Good god, what are we talking, a couple ounces ?!?!? Hell, skip the fries at lunch !!!
As for the ackerman, zero is fine for straight line racing but the OP's application (as far as I know) and mine would be a street car and you do want some ackerman or you end up with significant scrub.
As far as the ackerman discussion, from everything I read, if you get the outer tie rod intersect outside the balljoint, you will have ackerman. Maybe not the exact optimimum position, because of space limitations ie: the wheel, but you do the best you can. On a side note, My rack is out 8 1/2" in front of the wheel. The outer tie rod connection is 7" in front. My mind escapes me how far out the tie rod connect point is outside of the ball joint. I'll have to look at my notes. Also, using my test arms, I played around with the outer connect location, in and out, up and down and settled on a position that got bumpsteer to within .030" over 6" travel.
Tshell, Tried to PM you back, but you have that feature set to not accept PM's.
But, Thanx for kind words!
You can get him here toryshellehamer@yahoo.com
Posted By: Stanton
Re: Front Steer Rack Conversion - Part Deux - 03/05/14 07:54 PM
Its when doing things like these lower arms that it'd be really handy to have access to a 3D printer !!
Posted By: LA360
Re: Front Steer Rack Conversion - Part Deux - 03/06/14 11:50 AM
Quote:
Its when doing things like these lower arms that it'd be really handy to have access to a 3D printer !!
I doubt they would let me print a couple of titanium steering arms on the SLM at work. 
Posted By: gregsdart
Re: Front Steer Rack Conversion - Part Deux - 03/06/14 03:00 PM
Quote:
Quote:
Quote:
The steering arm web is IMO way over kill
Good god, what are we talking, a couple ounces ?!?!? Hell, skip the fries at lunch !!!
As for the ackerman, zero is fine for straight line racing but the OP's application (as far as I know) and mine would be a street car and you do want some ackerman or you end up with significant scrub.
As far as the ackerman discussion, from everything I read, if you get the outer tie rod intersect outside the balljoint, you will have ackerman. Maybe not the exact optimimum position, because of space limitations ie: the wheel, but you do the best you can. On a side note, My rack is out 8 1/2" in front of the wheel. The outer tie rod connection is 7" in front. My mind escapes me how far out the tie rod connect point is outside of the ball joint. I'll have to look at my notes. Also, using my test arms, I played around with the outer connect location, in and out, up and down and settled on a position that got bumpsteer to within .030" over 6" travel.
Steff, You covered both ends of the project IMO, excelllent engineering and great looking finished product. I would be proud to put this deal on a show car.
Posted By: STEFF
Re: Front Steer Rack Conversion - Part Deux - 03/09/14 07:32 PM
Posted By: Stanton
Re: Front Steer Rack Conversion - Part Deux - 03/09/14 10:15 PM
Wow, those things hang out way in front of the rotor. What size are those rotors ??
Very nice. When I saw your cad drawings I thought they were going to be milled out of a chunk. But seeing how you've made them its something just about anyone could tackle without great expense. Very nice! And I think the extra gussets make sense.
Would you care to share the actual specs on those ??
Posted By: STEFF
Re: Front Steer Rack Conversion - Part Deux - 03/10/14 12:44 PM
Quote:
Wow, those things hang out way in front of the rotor. What size are those rotors ??
Very nice. When I saw your cad drawings I thought they were going to be milled out of a chunk. But seeing how you've made them its something just about anyone could tackle without great expense. Very nice! And I think the extra gussets make sense.
Would you care to share the actual specs on those ??
Thanx!! Here's the info: From the center of the ball joint to the tie rod connection is 7", which is only a 1/2" further out from stock. The tie rod connection is also .625" outside of the ball joint. I had the gussets and base plates water jet cut from A-36 Hot Rolled Steel. Cost was $150 including material. Base Plate is 3/8" thick. Gusset is 3/4" thick. The Ball Joint Sleeves came from Speedway Motors. They were $7 each. I was able to have a friend at work machine the hole for the ball joint sleeve and tie rod tube in the main plate. The hole for the Ball Joint Sleeve was machined on a 7 1/2 degree angle to mimic the factory ball joint angle. The holes were machined to provide a slip fit for the BJ sleeve and tie rod tube. All parts were tig welded.
Posted By: STEFF
Re: Front Steer Rack Conversion - Part Deux - UPDATE!! - 03/30/14 07:32 PM
Finally finished my front end and just came back from a road test. The car drives GREAT!!! Goes straight, backs up with no issues etc.... Did a garage alignment, following instructions from Rick Jones article. Can't wait to get this thing down the track in two weeks at Mopars at the Rock!!
Posted By: MR_P_BODY
Re: Front Steer Rack Conversion - Part Deux - UPDATE!! - 03/30/14 07:40 PM
Cool
... Steff.. whats the length of the steering
arm from the C/L of the ball joint to the C/L of the
tie rod end... whats the turning radius... I'm moving
mine in about 1" and moving the rack back about 1 1/2"
to get a better turning radius
EDIT
I see you put the length in... thanks... hows the
turning radius
Posted By: STEFF
Re: Front Steer Rack Conversion - Part Deux - UPDATE!! - 03/30/14 08:05 PM
Quote:
Cool ... Steff.. whats the length of the steering
arm from the C/L of the ball joint to the C/L of the
tie rod end... whats the turning radius... I'm moving
mine in about 1" and moving the rack back about 1 1/2"
to get a better turning radius
EDIT
I see you put the length in... thanks... hows the
turning radius
Turning radius isn't as tight as before but it isn't all that bad either. I have the Pinto rack, which has 4 turns lock to lock. Just need to be a little more aware when pulling in to tight areas. No hair pin turns.....LOL!
Posted By: MR_P_BODY
Re: Front Steer Rack Conversion - Part Deux - UPDATE!! - 03/30/14 08:30 PM
Turning radius isn't as tight as before but it isn't all that bad either. I have the Pinto rack, which has 4 turns lock to lock. Just need to be a little more aware when pulling in to tight areas. No hair pin turns.....LOL!
I have the Pinto rack also and I think its just over
3 3/4 turns lock to lock but I didnt like my turning
radius for a street rod so thats why I'm moving things..
I'm gonna start on that next week... I'm finishing up
moving the body up 1" in the rear.. gotta do the same
thing in the front.. the springs I have are wrong
on both ends... I'm putting on 5# heavier rears and
moved the lower brackets... the fronts will take a bit
more work... I have the upper strut mounts on top of
the rail and I need them on the bottom with lighter
springs in front.. right now the struts are topped out
Posted By: 340RICK
Re: Front Steer Rack Conversion - Part Deux - UPDATE!! - 03/30/14 10:14 PM
Looks great Steff
glad to hear she drives nice
