Fabricated A-Body spindle ideas and discussion

[DionR]

And seeing as our cars are generally a few hundred lbs lighter, it should be sufficiently overbuilt.

And the S550 hub is huge. Significantly bigger than a Challenger rear hub, and that car weights a bunch more than a Mustang. I tried to fit the S550 hub inside of the drum-in-hat e-brake off a Challenger and there is no way, it was like 2” bigger in diameter and wanted to sit on the e-brake shoes. This thing is fairly massive.

And in case you are wondering, yes I have plans for a weld on axle end that would use this same hub. Something similar to this:

Big Bearing Ford Kit with E-brake

 

[DionR]

In my mind, the biggest potential benefit is being able to engineer in some positive caster. But that really only makes sense if the knuckle is cheap enough to build. The stock spindle seems to work fine so why spend a bunch of money for that.

I started down this road because I wanted a more robust wheel bearing setup with a built in tone ring. So those are a benefit to me, but maybe not others.

I could see moving the UBJ mount up an inch, but I don’t think it can go higher. Unless maybe the LBJ was dropped some, and that limit is maybe only 1/2” if at all.

I know that there is a guy that strongly advocates for a 1” drop, but I’m not clear on why that is better. This is where some geometry checks would come in handy.

One potential issue with a stock hub centerline is as the car is lowered, suspension travel is reduced. @72bluNblu has talked about this several times. He runs a QA1 LCA without the bump stops and gained most of his suspension travel back. But a small change in centerline like a 1/2” drop might work to help with that and still clear the wheel with the OTR end.

Just some thoughts.

 

[bjkadron]

In my mind, the biggest potential benefit is being able to engineer in some positive caster. But that really only makes sense if the knuckle is cheap enough to build. The stock spindle seems to work fine so why spend a bunch of money for that.

I started down this road because I wanted a more robust wheel bearing setup with a built in tone ring. So those are a benefit to me, but maybe not others.

Yes, the tone ring and better bearing is also where I see the main benefit. With ease of brake adapting and possibly a better (more serviceable) Lower balljoint situation and maybe bump steer improvements being possible improvement but not a main priority.

 

[DionR]

The one drawback to the S550 rear hub is that it requires a bolt to squeeze the bearings. The Mach 1 hub doesn’t require that and doesn’t seem to be more expensive, but the bolt pattern is not symmetrical and might be difficult to fit around the LBJ bolts.

 

[bjkadron]

The one drawback to the S550 rear hub is that it requires a bolt to squeeze the bearings. The Mach 1 hub doesn’t require that and doesn’t seem to be more expensive, but the bolt pattern is not symmetrical and might be difficult to fit around the LBJ bolts.

What year Mach 1?

 

[DionR]

If we were really slick, we could try and adapter the double LBJ most of the cars have now, like the Mach 1 spindle. Basically, instead of the strut rod attaching to the LCA, move it over to the knuckle and attach it with a ball joint. No idea how that geometry works though.

 

[DionR]

What year Mach 1?

This one says 16-22. Guessing this fits GT350, GT500 and Mach 1. Maybe anything with the magma ride?

More Information for MOTORCRAFT HUB395

 

[bjkadron]

If we were really slick, we could try and adapter the double LBJ most of the cars have now, like the Mach 1 spindle. Basically, instead of the strut rod attaching to the LCA, move it over to the knuckle and attach it with a ball joint. No idea how that geometry works though.

I think that would be going backwards., it would definitely make the geometry calculations more complicated. I'd say you would almost be better doing a new LCA like this angle kit. Corvette C5/C6 Mega Mantis Angle Kit

 

[DionR]

I think that would be going backwards., it would definitely make the geometry calculations more complicated.

Frankly, I don’t understand how they work. Seems like there are some pivots required where it doesn’t seem right to have a pivot. But I do know the theory behind them, and that is to get the LBJ pivot further under the spindle where you couldn’t put it physically. This gets the SAI in and reduces scrub radius.

But I brought it up more as a joke than anything.

 

[swisswill]

I'm with you guys, my goal is around wheel bearing, ABS, and better/more simplified brake options. Improved geometry is a side benefit for me, but if we can do it, let's do it. I only throw out alternative designs and production options because that's what I found in my research. I think we're best off coming up with a design that we can have a few sets made up to begin with, then others can have the files and build their own if they wish. Michigan Metalworks takes a different approach and I bring it up because it's stout, maybe lighter/maybe not, and they've already said they could do it, and if we brought them the design and files, it'll cost that much less to have it produced. But just another option.

On the rotor, if using a Ford hub, why not simplify the rotor fitment and use a Ford rotor? The '15 Mustang has a rotor that is 13.9" diameter while the SRT rotor is 14.17". All the necessary holes are perfectly sized to the hub already, same thickness, almost same diameter which means the four piston SRT calipers should have no problem playing nice with the rotor, and there is no need to use feeler gauge material.

Mustang

SRT

Have you seen MillerBuilt's fabricated spindle? It's a super nice piece.
Fabricated C5/6

Years ago I bought suspension analyzer to layout my '69 front and rear suspension. I'm going to see if I still have the CD for that. I was on a mac at the time and when I went back to PC forever later, I had all but forgotten about it. I might still have it. I'm going to look this weekend. If I do, I'll get it installed and then we can start getting measurements. Or maybe I send it to one of you guys that has better access to a vehicle than mine in storage.

 

[bjkadron]

I'm with you guys, my goal is around wheel bearing, ABS, and better/more simplified brake options. Improved geometry is a side benefit for me, but if we can do it, let's do it. I only throw out alternative designs and production options because that's what I found in my research. I think we're best off coming up with a design that we can have a few sets made up to begin with, then others can have the files and build their own if they wish. Michigan Metalworks takes a different approach and I bring it up because it's stout, maybe lighter/maybe not, and they've already said they could do it, and if we brought them the design and files, it'll cost that much less to have it produced. But just another option.

On the rotor, if using a Ford hub, why not simplify the rotor fitment and use a Ford rotor? The '15 Mustang has a rotor that is 13.9" diameter while the SRT rotor is 14.17". All the necessary holes are perfectly sized to the hub already, same thickness, almost same diameter which means the four piston SRT calipers should have no problem playing nice with the rotor, and there is no need to use feeler gauge material.

Mustang
View attachment 1716391448

SRT
View attachment 1716391449

Have you seen MillerBuilt's fabricated spindle? It's a super nice piece.
Fabricated C5/6

Years ago I bought suspension analyzer to layout my '69 front and rear suspension. I'm going to see if I still have the CD for that. I was on a mac at the time and when I went back to PC forever later, I had all but forgotten about it. I might still have it. I'm going to look this weekend. If I do, I'll get it installed and then we can start getting measurements. Or maybe I send it to one of you guys that has better access to a vehicle than mine in storage.

This rotor is the one that is mentioned in post 7 but it's a very poor choice of rotor design. See the video explanation here:


I will see if I can find the measurements I did when I previously analyzed. I'd be glad to run the numbers.

 

[swisswill]

That makes sense, and is unfortunate.

 

[DionR]

The S197 rotor is a better idea, still 14" and a better design. And if the knuckle were based about the S197 4 Piston brakes, the S550 6 piston calipers would bolt on with the 13/14 GT500 15" rotor. Or so I have read.

The SRT rotor has the advantage in my mind though as it is slightly bigger in diameter and has more offset so the caliper doesn't stick out as far.

That said, the S197 setup has the advantage for upgradeability. The SP setup upgrades to the HC 6 piston brakes but that takes a wheel bigger than 18".

I looked for GT350 calipers on RockAuto and didn't see any. This makes me think that while they might be easy to source, they aren't as widely available as the 14" S197 and S550 stuff.

 

[DionR]

Have you seen MillerBuilt's fabricated spindle? It's a super nice piece.
Fabricated C5/6

That one is new to me. Looks good though.

 

[DionR]

It might be kind of hard to decipher but here is how the Mach 1 hub might be made to work:

 

[DionR]

Definitely won't work in it's original orientation.

 

[jos51700]

We have a sheet metal laser where I work. If you want to send flat patterns and material thicknesses, we might be able to save you some money.

 

[67Dart273]

This is just incredible!!

 

[DionR]

We have a sheet metal laser where I work. If you want to send flat patterns and material thicknesses, we might be able to save you some money.

Is there is a material thickness limit?

 

[MV8]

Are you still asking for suggestions to reduce the scrub without excessive kpi?

 

[DionR]

Are you still asking for suggestions to reduce the scrub without excessive kpi?

Absolutely! All ideas are welcome.

To be clear, Steering Angle Inclination (SAI) and King Pin Inclination (KPI) are the same, correct? I've always assumed they are and have been referencing SAI, so when you say "KPI" I just want to make sure we are talking about the same thing.

 

[MV8]

We are. A few different acronyms have been used over the years.

• Invert the LBJ. This will raise the ball center about an inch and more effective than moving the UBJ.
• By putting the stud boss in the LCA, the end of the LCA is shorter. The LBJ can also be further outboard/closer to the rotor without the end of the LCA contacting the rotor at full bump.
• You probably don't want to do this, but floating calipers allow the rotor to be closer to the wheel center, reducing scrub from a given wheel offset. The floater needs no more than the clearance required with a new outer pad. Fixed calipers are thicker outboard of the rotor to fit pistons.
• Design the arms to clear more rim offset and still have an adequate turning radius.

 

[swisswill]

The S197 rotor is a better idea, still 14" and a better design. And if the knuckle were based about the S197 4 Piston brakes, the S550 6 piston calipers would bolt on with the 13/14 GT500 15" rotor. Or so I have read.

The SRT rotor has the advantage in my mind though as it is slightly bigger in diameter and has more offset so the caliper doesn't stick out as far.

That said, the S197 setup has the advantage for upgradeability. The SP setup upgrades to the HC 6 piston brakes but that takes a wheel bigger than 18".

I looked for GT350 calipers on RockAuto and didn't see any. This makes me think that while they might be easy to source, they aren't as widely available as the 14" S197 and S550 stuff.

The S197 and S550 stuff seems super easy to source. RockAuto has black S197 four piston calipers for $116 a piece, rotors from $41, pads from $10, and hubs from $63 (sometimes get what you pay for with pads/rotors/hubs), but this can be done for a very reasonable price.

I found suspension software receipts and it turns out I bought the Autowares software, which isn't quite as robust as the Performance Trends version but will probably serve the purpose. I've got to hunt up the CD and we should be good to start plotting this out. There's also a 10 day free trial of suspension analyzer so if we have measurements we can use the free download and get it dialed in w/in a 10 day period, maybe.

 

[opus65]

The S197 and S550 stuff seems super easy to source. RockAuto has black S197 four piston calipers for $116 a piece, rotors from $41, pads from $10, and hubs from $63 (sometimes get what you pay for with pads/rotors/hubs), but this can be done for a very reasonable price.

I found suspension software receipts and it turns out I bought the Autowares software, which isn't quite as robust as the Performance Trends version but will probably serve the purpose. I've got to hunt up the CD and we should be good to start plotting this out. There's also a 10 day free trial of suspension analyzer so if we have measurements we can use the free download and get it dialed in w/in a 10 day period, maybe.

Is something like the Lexus adjustable upper ball joint just too weak to be of any help?

 

[DionR]

Here is the info I was thinking of in regards to fitting 18" wheels with the 15" S550 brakes. Turns out it was an S650 Dark Horse with 15.3" rotors that they were test fitting.