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Discussion Starter #1
reviving an old subject, but I don't mind throwing myself under the bus.

over on sccoa, in 2013/2014, fast92sc was talking about making them again, the last run being made 2009ish. Looking at his profile he hasn't been here in a year. Anyone know if he is now making them again?

From what I herd, AJE isn't the best. I'm assuming they got their missalignment problems worked out. One has to buy their lca's, which seems to be the expensive and problematic part. Anyone ever re-work AJE's to take stock t-bird lca and strut rod? Using a jig or measuring? Ya with a jig one could make the whole thing but this might be easier, faster, less R&D....
 

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The geometry on the SRB end needs to be so heavily modified that whatever time you save by starting with the AJE would be moot, the mounting for the LCA pivots are different as well since they don't use bushings. plus the AJE is quite costly, the best way to do it is what fast92sc did and build a jig around a factory stock K member and build the new one around it, not that hard from there to lay the tubing out.
 

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The geometry on the SRB end needs to be so heavily modified that whatever time you save by starting with the AJE would be moot, the mounting for the LCA pivots are different as well since they don't use bushings. plus the AJE is quite costly, the best way to do it is what fast92sc did and build a jig around a factory stock K member and build the new one around it, not that hard from there to lay the tubing out.
idk maybe I'm over thinking the work involved with having to build an entire k member. making a jig for the mounting points would be easy, the rest??? pic for further reference, here's my thoughts



tubing along red lines would be easy. Yellow forms square, exact dimensions unknown, but I suppose the exact size of the square isn't so important as long as all the attaching points for parts is the same. The other tubes unmarked would then vary, of course, on the square.

I would think one jig that holds every piece of tube would be best but I suppose one could build a separate jig for the yellow square and then weld to the other stuff on the main jig, using rack bolt points as reference. Either way alot of R&D time, not counting the important parts that the suspension parts bolt to. Almost all dimensions for the tubes are unknown.

Thats why I thought instead of having to build a jig that has to line up 10 tubes plus brackets, then build the whole member, build one that just uses the member to car points and member to lca and strut rod points- all could be done easily with stock k. Then just take aje's, cut off their lca brackets, bolt to jig, fab up and weld on new brackets for stock t-bird lca's, then done! the suspension mount points would be were they needed to be.

Price of tubing, experimenting, mistakes, time trying to figure out dimensions I/we don't have. Thought it might be easier/cheaper starting with a member that had the missing dimensions. Wouldn't most the work already be done? approx how much $ in tubing would it cost to build the whole member?
 

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just some quick #'s, dom 2" with .25 wall is about $20 a foot. I've never seen mn12 tubular k in person but I'm guessing that's probably close to what they use for the 2 tubes with red lines? Each about 2ft long, thats $80, not including tax, the other eight tubes and brackets, or welding. So a conservative number, 150-200 for the member? Cost of materials to make the elaborate jig, $100? So total 250-300+?

Not trying to rant or anything like that. Just trying to get an idea what it would take to make a whole K vs modifying aje's, and if modifying is even an option.
 

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just some quick #'s, dom 2" with .25 wall is about $20 a foot. I've never seen mn12 tubular k in person but I'm guessing that's probably close to what they use for the 2 tubes with red lines? Each about 2ft long, thats $80, not including tax, the other eight tubes and brackets, or welding. So a conservative number, 150-200 for the member? Cost of materials to make the elaborate jig, $100? So total 250-300+?

Not trying to rant or anything like that. Just trying to get an idea what it would take to make a whole K vs modifying aje's, and if modifying is even an option.
AJE uses chromoly now according to all available info. Here it is at Jegs: AJE Suspension TB-80UM, AJE MN12 Thunderbird Tubular Front K-Member and Components | AJE Suspension

The K member cost isn't the real problem. The real problem is that his design doesn't reuse stock LCAs and his solution is difficult to align and are reportedly crap.

If you're willing to spend that much on raw materials then just buy the one they make and figure out how to solve the LCA problem.

If I could have just spent #360 on his then I would have done that instead of modifying my stock K member.
 

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Discussion Starter #6
AJE uses chromoly now according to all available info. Here it is at Jegs: AJE Suspension TB-80UM, AJE MN12 Thunderbird Tubular Front K-Member and Components | AJE Suspension

The K member cost isn't the real problem. The real problem is that his design doesn't reuse stock LCAs and his solution is difficult to align and are reportedly crap.

If you're willing to spend that much on raw materials then just buy the one they make and figure out how to solve the LCA problem.

If I could have just spent #360 on his then I would have done that instead of modifying my stock K member.
that was my idea, as a mentioned in the last post. make a jig using ford' s stock, non tubular k. Jig would be easy to make since you only need it to include member to car mounting points and member to lca and strut rod mounting points.
then use it to weld on new brackets for stock lca components(lca and strut rod) to aje's member in the original, non-tubular k member's location. So in theory, no problems with lca since stock ford lca and strut rod are reused, and no alignment problems since they would be mounted in the exact mounting point locations as the stock, non-tubular k. I'm I not taking something into account?

Thats why I thought instead of having to build a jig that has to line up 10 tubes plus brackets, then build the whole member, build one that just uses the member to car points and member to lca and strut rod points- all could be done easily with stock k. Then just take aje's, cut off their lca brackets, bolt to jig, fab up and weld on new brackets for stock t-bird lca's, then done! the suspension mount points would be were they needed to be.
 

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Part of why you're complicating things is that you're using the AJE as your frame of reference. This is a custom project, there is no guideline.

The LCA pivots require a box structure for the oem bushing and cam bolt setup, the strut rods require diagonal pieces of flat steel. Use the factory stock k member to make a jig to locate those(and rack) and all you have to do to make the part you highlighted in yellow is connect them all together. Keep in mind you have to do this even if you did choose to modify the AJE, how else would you know how to find the proper locations for the factory LCA and strut rod mounts?
 

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that was my idea, as a mentioned in the last post. make a jig using ford' s stock, non tubular k. Jig would be easy to make since you only need it to include member to car mounting points and member to lca and strut rod mounting points.
then use it to weld on new brackets for stock lca components(lca and strut rod) to aje's member in the original, non-tubular k member's location. So in theory, no problems with lca since stock ford lca and strut rod are reused, and no alignment problems since they would be mounted in the exact mounting point locations as the stock, non-tubular k. I'm I not taking something into account?
I think you generally have it. I'm not saying it's going to be easy because if it was I'm sure that someone would have already worked it out by now.
 

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Discussion Starter #9
Part of why you're complicating things is that you're using the AJE as your frame of reference. This is a custom project, there is no guideline.

The LCA pivots require a box structure for the oem bushing and cam bolt setup, the strut rods require diagonal pieces of flat steel. Use the factory stock k member to make a jig to locate those(and rack) and all you have to do to make the part you highlighted in yellow is connect them all together. Keep in mind you have to do this even if you did choose to modify the AJE, how else would you know how to find the proper locations for the factory LCA and strut rod mounts?
No, I'm not confused because I'm using aje's framework as a reference. To be honest, I'm not confused at all, there's just some info I don't know.
I meant one option, was to make the box structure for the lca and the diagonal pieces of flat steel-your words, and weld them to aje's using one simple jig.

If I was to make the whole k member, I planned to make it the way you mentioned. What I was "confused" about or what I didn't know is as follows,

Diameter and wall thickness of tube to use- obviously a big deal, mostly if one builds too small/weak. Some places need bigger tubes than others, cause those places need to be stronger than others. Sure I could build the whole entire thing using only 3" od with .5 wall but that would be way more than needed and way more cost. Too small, lets not go there. My point, one can't use just any size tube. SO what dia and were?

This isn't such a big deal as the tube, but the yellow square, as we call it, can't be just any dimension either. One has a little more wiggle room here. Width of the square- width lca mount points would somewhat gauge that. There is also the distance from the square to the top of the member, the location of the rack would determine were that needs to be. Length, front to back, would be gauged by lca and strut rod location. as I said there is wiggle room here.

Have you ever tried welding a perfect square using only a tape measure and a framing square? I find it a pain, Having a separate jig just for the square would make it much easier. Then a main jig, that holds the square via rack mounts, lca mounts, strut mounts, engine mounts, ect.. but that adds cost, not much though.

I'm comparing cost and time here. Building the whole thing, how much would the tubing and plate cost again? plus the yellow square jig and the extra metal needed for the main jig for all the extra mounts(engine, rack, sway bar) that I will need to weld on, the cost of all the extra welding, VS. One simpler main jig, a little steel plate, and adj's member?

The whole reason I had the idea of modifying adj's is one wouldn't have to guess the diameter and wall thickness of tubing, a lot simpler(and cheaper) jig could be used, and alot less time making stuff
 

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When did I ever say you were confused? I said that you're making things complicated. The Jig you'd need to build for the yellow square with factory mounting will provide literally half the necessary positioning to build the K member from scratch, only additions you'd have to add to that fixture are the motor mounts and the frame rail/ sway bar sections. Reverse engineering the AJE is just an unnecessary and fruitless task for the cost of entry and the time spent modifying it, especially if it's just to figure out wall thickness and tubing diameter. AJE didn't put much if any R&D into theirs to determine that aspect, in fact they probably used the same tubing stock as they do for the run of the mill Mustang K members they specialize in primarily, and that information can be found from a basic google search from varius tube K member builders. The builder on SCCoA provided his chosen thicknesses and diameters as well IIRC.
 

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Discussion Starter #11
First all I really appreciate the help.
oops, complicated, not confused, sorry bout that.
In regards to building a whole k, I thought if one tried to make one jig for everything it might get a little cramped and hard to work with. Hence a smaller jig just for the square and a bigger one to weld the square to everything else. But that's not important.

K so aje probably didn't crunch numbers when selecting tubing. But I'd still need to find out what size of tubing to use for which parts, not necessary the sizes aje uses, but the size that can/should be used and were, and the total cost for materials. I can figure out the total cost but sizes of tube? Sure, I could guess, it would probably be fine, but it would suck to build it too light and have it break! I'll start googling it, as you mentioned.

I wasn't going to cut apart adj's member for ANY reason, not even to figure out tubing sizes. That was never the plan.

Reverse engineering? I dunno If I'd call welding 4 brackets on aje's member reverse engineering. It's not like the whole thing would have to be cut all apart and welded back together. Just welding on new brackets for stock components, that's it.
 

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But I'd still need to find out what size of tubing to use for which parts, not necessary the sizes aje uses, but the size that can/should be used and were, and the total cost for materials. I can figure out the total cost but sizes of tube? Sure, I could guess, it would probably be fine, but it would suck to build it too light and have it break! I'll start googling it, as you mentioned.
i worked in a steel warehouse for 9 years and be a fabricator by trade i can tell you the use nothing special just DOM tubing like: 1020 DOM A513 Round Steel Tube x 1.5 OD x .188 wall or 1020 DOM A513 Round Steel Tube x 1.5 OD x .250 wall for your yellow outlined part and 1.0 OD x .156 or x.250 Wall for the rest from what i see . If they would use chrom moly tube the k member would*n sell for 360 $$ plus shipping, plus the control arms for 450 $$
May i ask why do you want a tubular k member so bad??
there is only 30 lb of weight saving in it ,see Coyote 5.0 Engine Swap thread,page 2
if you want the k member lighter cut out the original and brace that one up ,what i* gona do because close to 900$ for 30lb of weight saving does not cut it
if you need a price look here MetalsDepot® - Buy DOM Round Steel Tube Online!

so long

hoschy
 

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First all I really appreciate the help.
oops, complicated, not confused, sorry bout that.
In regards to building a whole k, I thought if one tried to make one jig for everything it might get a little cramped and hard to work with. Hence a smaller jig just for the square and a bigger one to weld the square to everything else. But that's not important.

K so aje probably didn't crunch numbers when selecting tubing. But I'd still need to find out what size of tubing to use for which parts, not necessary the sizes aje uses, but the size that can/should be used and were, and the total cost for materials. I can figure out the total cost but sizes of tube? Sure, I could guess, it would probably be fine, but it would suck to build it too light and have it break! I'll start googling it, as you mentioned.

I wasn't going to cut apart adj's member for ANY reason, not even to figure out tubing sizes. That was never the plan.

Reverse engineering? I dunno If I'd call welding 4 brackets on aje's member reverse engineering. It's not like the whole thing would have to be cut all apart and welded back together. Just welding on new brackets for stock components, that's it.
If that was just 'it' I'd agree with your plan :D, the issue arises from the fact that the AJE will need to be cut up to mount the two LCA pivot boxes to some extent, and will most definitely need to be cut up to mount the two strut rod diagonals. They won't even necessarily work within the AJE's footprint, remember, The AJE uses very simple pivots on the K member itself, all adjustment comes from the threaded rods in the arms themselves, the stock K member OTOH contains the adjustment mechanism on a cam bolt system, which take up a large footprint in the K member structure. So it'll need to be jigged up for the positioning of the new components as well as hold the K member AND true in the likely event that it won't keep it's shape when you do cut/weld it. To that end I just don't see the savings.
 

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Thanks to Bad-Hoschy, that's the sort of info I'm looking for. I figured dom, but size and wall thickness I didn't know. Yes one can guess it... Better to overbuild.

Finding nada on google on dia and wall thickness for any k, no matter application.

Saw in person a 88 firebird tube k, Main crossmember tube is 1.5 OD all others were 1.25OD. Wall unknown, of course.

I know how alignment is done with stock and aje's members. And yes, I/we don't know(yet) if the bracket to hold the strut rod(plate to be welded on) would land well enough in aje's footprint so they could be attached adequately.

I herd of some using mig, I thought tig would be necessary for something like this?

Any word if fast92sc ever got back to making his like he wanted?

My t-bird is buried in snow at the moment. Hopefully this weekend I'll do enough digging so I can get some rough dimensions off the stock K so I can figure out approx tubing that will be needed. Then comes a closer price for tubing.
 

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Hi Fordjoe

i know that josh aka OxmanWI has the same AJE k member for his project maybe there is a chance he could give you dimensions on that if you want to ask him, plus he got the original out of the car he posted a picture in the Coyote 5.0 Engine Swap thread .
i have accses to one in the junkyard on the weekend depends on weather ,we expect lake effect ****, i could get some dimensions to


so long

hoschy
 

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Hello:wavey:

I'm lost on the appeal for the tube front K?:zdunno:

Unless you need to mod a special oil pan???

I notched mine.
special oil pan + lowered engine.

:zbench:
less weight using high tensile strength steel, clearance for larger oil pan and longtube headers :D
 

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less weight using high tensile strength steel, clearance for larger oil pan and longtube headers :D
Well, I think that's where Tess is going. I just modded mine to get clearance for my long tubes and for a bigger oil pan. The weight savings came from cutting out some metal. I could have saved more weight I guess but that would have been more cuts. :D
 

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I think too many people are becoming interested in tubular front subframes. When they have no reason to. Especially on street driven cars.
 
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