1" drop spindle, '70 drum style?

[Swede958]

Hey Degins, I'm in Austin too! Where are you getting all this foundry work done for these spindles? (Just curious... I'm in a foundry course down at Txstate)

I think the most economical thing to do to would be to design a spindle with a 1" drop, a cast in boss for a relocated steering arm, and to find a way to utilize a readily available hub. One idea would be to use a newer model mustang hub, like 94-95. They are like 54$ new with sealed bearings. The other option (and I'll have to go through my catalogue) is too see if there's a compatible hub using replaceable bearings that will work off the shelf (a la Baer). One other option might be to use, instead of one caliper option, cast the ears for caliper mounting in such a way that multiple caliper types could be used with little modification. Again, research would have to go into specific caliper mounting but instead of being stuck with one set of holes, small starter points (maybe 2mm x 1mm) could be machined in leiu of holes. I.e. Use holes A for stock caliper/stock rotor, Holes B for KH caliper/stock rotor, Holes C for PBR caliper/12" (+/-) rotor, Holes D for PBR/ 13" rotor... or whatever the market may want.

Not sure if it will fly, but if you can get a cad drawing a send it to me... I may be able to run out a copy on the LOM machine, then maybe cast a rough version? Just a thought.

 

[bnickel]

hey Swede, haven't seen you around in a while. how are things coming with the stang?

 

[Helmantel]

I think a shorter steering arm is definately desirable.

It would appeal to those with rack and pinions (reduced turning radius) as well as those who want quicker steering with their steering box. On 65-66 cars you can install a Shelby quick steering kit, but not on later ones. Those with the early cars would save the cost of the quick steering kit.

Like others have mentioned, leaving some extra meat on the steering arm to allow for multiple positions of the tie rod holes is a possibility. Maybe the 65-66 vs 67+ steering arm geometry issue could addressed in the same way?

Actually, a lowered tie rod position would also be desirable, to reduce bumpsteer. This leaves of course the question where the tie rod should be positioned, as different variations of "Shelby drops" would require different tie rod locations and an adjustable bumpsteer kit. However, a tie rod position that eliminates bumpsteer with a very common 1" Shelby drop and 3 deg caster would be a possibility.

I think that a set of $300 set of 1" drop spindles quick steering with improved bumpsteer would sell like hot cakes

 

[CochinoFilipino]

I’m interested and I think there would be more signs of demand once the piece actually exists. Then there will be more enthusiasm and discussion of its benefits.

 

[bnickel]

I think a shorter steering arm is definately desirable.

It would appeal to those with rack and pinions (reduced turning radius) as well as those who want quicker steering with their steering box. On 65-66 cars you can install a Shelby quick steering kit, but not on later ones. Those with the early cars would save the cost of the quick steering kit.

Like others have mentioned, leaving some extra meat on the steering arm to allow for multiple positions of the tie rod holes is a possibility. Maybe the 65-66 vs 67+ steering arm geometry issue could addressed in the same way?

Actually, a lowered tie rod position would also be desirable, to reduce bumpsteer. This leaves of course the question where the tie rod should be positioned, as different variations of "Shelby drops" would require different tie rod locations and an adjustable bumpsteer kit. However, a tie rod position that eliminates bumpsteer with a very common 1" Shelby drop and 3 deg caster would be a possibility.

I think that a set of $300 set of 1" drop spindles quick steering with improved bumpsteer would sell like hot cakes

i think we are complicating this too much, that's why i suggested only doing the 1" drop and not messing with anything else, a stock spindle with a 1" drop won't be optimal for every combo out there but for an otherwise stock car it would provide a much better geometry than a stock one without the drop. there are literally millions of basically stock mustangs that could benefit from the 1" drop but much, much fewer that have rack and pinion and even fewer still that will actually try to measure and correct the bumpsteer. by simply adding the dropped spindle a lot of people won't even need to address the bumpsteer issue as the relationship of the LCA and the tie-rods will still be factory stock add a 1" lowering spring and even then it won't be altered much. even with teh shelby/arning drop it won't be all that bad. for those few hardcore guys like us that will do an UCA drop even further than the shelby/arning drop then we'd need to address the issue with the available options like the baer tracker kit or the pro-motorsports kit.

like i said, possibly consider adding a boss for relocating the tie rod 1" further up the steering arm for the rack and pinion and quick steer type guys but i think the marker would be better for a stock style spindle with ONLY the 1" drop based on a 70 drum unit. even if the tie rod was relocated for better bumpsteer it still wouldn't cure it and you'd still wind shimming the tie rod or using a bumpsteer kit and also with the spindle pin dropped 1" you might run into clearance issues by relocating the steering arm down too far.

i say keep it simple for better marketability. don't get me wrong, i'm all for relocating the tie rod for both bumpsteer and turning radius i just don't think the market is big enough for it to be profitable, is all.

 

[valley82]

If you guys end up making these sign me up for two sets, one for me and the other for my brother in law.

Gettin ready to buy a complete suspension package from open tracker, and the discbrake kit I've got from JMC requires the '70 spindles.

 

[67efivert]

not trying to cut into designs stuff but heres a 2" drop set http://www.fatmanfab.com/07page17.htm

 

[bnickel]

not trying to cut into designs stuff but heres a 2" drop set http://www.fatmanfab.com/07page17.htm

i've seen the fatman spindles and they are not pretty at all. in fact they are downright scary looking. also, the only option you have for the brakes is granada calipers and rotors and that's it. you can't even use an aftermarket kit for a stock granada spindle.

 

[69gmachine]

i think we are complicating this too much, that's why i suggested only doing the 1" drop and not messing with anything else,

As much as I hate to agree with BNickle (because of cost), from a marketing perspective he may be right, especially considering Degins desire to produce kits. I also understand Degins desire to mitigate the risk of investing a large amount of capital in an unproven design by trying to guage market volume, but designing a product as critical as a spindle is not best done by group consensus IMHO.

I've decided to go with a custom aluminum spindle so I can spec exactly what I want, and use the alum hub and Coleman rotors I already have.

BNickel forgot to mention that reduced unsprung weight is another benefit of aluminum.

I sincerely hope Degins produces something that improves on the stock design. I'm sure the market is there if done right.

 

[SNAKEPILOT]

To summarize the benefits of the drop spindle:
1. Lower ride height without losing suspension travel.
2. Ability to run wider wheels? Max now is 4.75 bs on a 17" wheel, would the drop allow a 5.5 bs?
3. Better handling from better scrub radius?
And the options:
4. Shorter steering arm for decreased turn radius? Wouldn't anyone with wider tires want this, not just the R&P users?
5. Disc brake type. I have Degins "new" Granada spindles which are 70-73 disc spindles. How would my Wilwood hubs and discs work with a dropped "drum" spindle?

 

[bnickel]

To summarize the benefits of the drop spindle:
1. Lower ride height without losing suspension travel.
2. Ability to run wider wheels? Max now is 4.75 bs on a 17" wheel, would the drop allow a 5.5 bs?
3. Better handling from better scrub radius?
And the options:
4. Shorter steering arm for decreased turn radius? Wouldn't anyone with wider tires want this, not just the R&P users?
5. Disc brake type. I have Degins "new" Granada spindles which are 70-73 disc spindles. How would my Wilwood hubs and discs work with a dropped "drum" spindle?

the hubs and discs should work fine provided they are based on the 70 up design, that shouldn't change if the 70 style drum spindle is used. in fact the calipers would still be able to be used you'd just need a different caliper bracket, but i'm pretty sure wilwood makes a bracket for the 70-73 drum spindle, if they would sell you just the bracket.

one of these days i may cut up and extra set of drum spindles and do a little cut and paste to see what kind of backspacing could be run with the stock UCA location and the shelby/arning drop. however by the time i'm able to get around to it Degins may already have it figured out.

i like the fact that the car could be lowered without compromising suspension travel and still lowering the center of gravity and the benefits of being able to use a wider wheel up front and an improved scrub radius. a drop spindle would allow such an inproved front suspension, that if combined with something like a TCP or GW strut conversion you would have the ultimate in handling from an early stang short of cutting out the shock towers and completely redesigning the entire suspension.

 

[70vert]

I've decided to go with a custom aluminum spindle so I can spec exactly what I want, and use the alum hub and Coleman rotors I already have.

BNickel forgot to mention that reduced unsprung weight is another benefit of aluminum.

Gmachine,
I shudder to ask this, but where are you looking at getting a custom spindle done, and what is the cost looking like? I understand that a handling benefit on rough roads is one of the benefits of reduced unsprung weight, as well as ride of course. (hides wallet)

 

[69gmachine]

AFX (https://secure13.nexternal.com/shar...usType=BtoC&Count1=208614528&Count2=125754952) makes a spindle for the 1st Gen Camaro that has a removable steering arm, has mounting ears for the big PBR 2 piston 'vette caliper, and uses the C5 bolt on spindle/hub assembly. They're currently on back order, but they go for $695/pr w/C5 hub assy, but no steering arm (I'll use the tall one and see if I can get it sans hub to save a little on the cost). They will put in whatever taper you want for the ball joints. A steering arm is another $175, but the only ones I saw on their website appear to be front steer. I may have to get someone like Coleman to make a custom set for rear steer. Then I will need to have a custom spindle pin assembly made that uses the Ford spindle pin with a backing plate that will bolt in where the C5 assembly normally goes. I just happen to have a few Ford pins laying around that were meant to be used in a custom fabricated upright. As you can see, I will have well over a grand in these by the time they're ready to bolt on, but they will be light, allow the use of a late model 17x9" wheel up front, and allow me to retain my PBR 'vette calipers

 

[Helmantel]

Some seem to think that raising the spindle pin reduces the scrub angle. It doesn't but increases scrub instead. Not by much, but it certainly doesn't decrease. See picture

Of course, when the raised pin allows the installation of wheels with more backspacing, scrub will be reduced.

How many features degins wants to build into these spindles, that's up to him. I posted some ideas and so did others, so its up to him to judge these ideas and see if they are feasible. If anything, he can keep it in mind when designing the molds so that they may be added later by just changing the machining operations rather than the whole mold (like the shorter steering arm or maybe a late model type spindle pin to allow a Fox body/SN95 hub)

 

[69gmachine]

Helm,

Nice picture, and you are absolutely correct that raising the spindle does not by itself improve scrub radius. However, there is a way to reduce scrub angle by raising pin height, and that is by using deeper offset wheels, that you cannot install on a stock spindle due to fouling with the upper bj (at least with 17" wheels). That will pull the CL of the wheel/tire in towards the car to come closer to the SIA.

 

[Helmantel]

That's what I meant to say with the following

Of course, when the raised pin allows the installation of wheels with more backspacing, scrub will be reduced.

FYI: MustangSteve had a set of bullet wheels narrowed from 8 to 7", so that they fit without a spacer (or maybe a thin one) with no rubbing and reported a noticable improvement insteering feel and effort. The wheels now have a 4.65" backspace.

 

[70vert]

Hope 17x9, 5.5bs will work

with this drop spindle. I have Coy's wheels front and back - 17x8, 4.75bs front, 17x9, 5.5bs rear, and am hoping to keep the same wheel style - just order two new 17x9s. Sure will make keeping a spare easier.

I would be amazed and very pleased if this allowed the use of 275 rubber up front. Trans-Am convertible here I come!

Helm,

Nice picture, and you are absolutely correct that raising the spindle does not by itself improve scrub radius. However, there is a way to reduce scrub angle by raising pin height, and that is by using deeper offset wheels, that you cannot install on a stock spindle due to fouling with the upper bj (at least with 17" wheels). That will pull the CL of the wheel/tire in towards the car to come closer to the SIA.

 

[degins]

As much as I hate to agree with BNickle (because of cost), from a marketing perspective he may be right, especially considering Degins desire to produce kits. I also understand Degins desire to mitigate the risk of investing a large amount of capital in an unproven design by trying to guage market volume, but designing a product as critical as a spindle is not best done by group consensus IMHO.

I've decided to go with a custom aluminum spindle so I can spec exactly what I want, and use the alum hub and Coleman rotors I already have.

BNickel forgot to mention that reduced unsprung weight is another benefit of aluminum.

I sincerely hope Degins produces something that improves on the stock design. I'm sure the market is there if done right.

69gmachine,
As I have stated before, my inclination is not in the performance area. That said, I have no intention of blindly following a consensus opinion. My talent is in bulldozing through the debris and getting things done.

I have gleamed from this discussion that many user wish to use tires with larger backspacing and diameter than is currently feasible using the standard spindle. This spindle should be compatible with a performance disc brake caliper and it would be optimal if it had multiple tie rod mount points or a replaceable steering arm like on earlier Fords. It would be nice to reduce the rotating mass.

This need could be fulfilled using a drop spindle that would place the upper ball joint closer to the center of the wheel and thus less prone to interfer with the rim. The magnitude of the drop is limited since one could introduce new rim interference issues.

None of this matters unless you guys can come to overcome the common prejudice about cast spindles. This leads me to a long (and probably boring) discussion of the cast vs forged issue.

The fact is that a properly forged part will have more tensile strength than a part properly cast from the SAME material. This allows the use of a marginally less costly material. This matters when one is manufacturing 100s of thousands of part in a continuous run. The 5-10% material cost savings and the less costly continous production nature of forging more than offsets the extreme cost of developing the production dies and equipment. This advantage vanishes when one produces the product in limited batch runs. The cost of a set of forging dies could be $50000 or more. So, for limited production runs, one resorts to casting superior materials that contain higher concentrations of key EXPENSIVE alloying agents like Nickel, Molybdenum, and Chromium. The casting method is more labor intensive, but doesn't require the massive investment in equipment.

The casting must contain materials that will result in a greater or equal yield strength than the forging. Yield strength is the key issue (definition: The stress a material can withstand without permanent damage). Forgings, by virtue of being squished into the die, have fractionally higher yield strength in the direction of the squish. Some regions of the forged part will be stronger than others. A cast part has equal strength throughout. So, a properly cast part with yield strength that is equal to the forged part is generally superior. The key here is the word PROPERLY. The cast part must be correctly heat treated and be free of internal defect. Internal defects in a casting are, in large part a feature of the design of the mold and the casting process. The casting producer uses x-ray analysis of cast samples to assure internal integrity. Acoustical analysis (analysing the stuck ring tone of a part will also assure quality). I compare the yield strength of my cast part against the yield strength of one of the arms of the spindle. The arm is a region of the forged spindle that was squished into the die and thus exhibits the maximum strength of the part. The cast part must have yield strength greater than the arm of the forged spindle.

Thanks everyone for your continued valuable input.

 

[bnickel]

69gmachine,
As I have stated before, my inclination is not in the performance area. That said, I have no intention of blindly following a consensus opinion. My talent is in bulldozing through the debris and getting things done.

I have gleamed from this discussion that many user wish to use tires with larger backspacing and diameter than is currently feasible using the standard spindle. This spindle should be compatible with a performance disc brake caliper and it would be optimal if it had multiple tie rod mount points or a replaceable steering arm like on earlier Fords. It would be nice to reduce the rotating mass.

This need could be fulfilled using a drop spindle that would place the upper ball joint closer to the center of the wheel and thus less prone to interfer with the rim. The magnitude of the drop is limited since one could introduce new rim interference issues.

None of this matters unless you guys can come to overcome the common prejudice about cast spindles. This leads me to a long (and probably boring) discussion of the cast vs forged issue.

The fact is that a properly forged part will have more tensile strength than a part properly cast from the SAME material. This allows the use of a marginally less costly material. This matters when one is manufacturing 100s of thousands of part in a continuous run. The 5-10% material cost savings and the less costly continous production nature of forging more than offsets the extreme cost of developing the production dies and equipment. This advantage vanishes when one produces the product in limited batch runs. The cost of a set of forging dies could be $50000 or more. So, for limited production runs, one resorts to casting superior materials that contain higher concentrations of key EXPENSIVE alloying agents like Nickel, Molybdenum, and Chromium. The casting method is more labor intensive, but doesn't require the massive investment in equipment.

The casting must contain materials that will result in a greater or equal yield strength than the forging. Yield strength is the key issue (definition: The stress a material can withstand without permanent damage). Forgings, by virtue of being squished into the die, have fractionally higher yield strength in the direction of the squish. Some regions of the forged part will be stronger than others. A cast part has equal strength throughout. So, a properly cast part with yield strength that is equal to the forged part is generally superior. The key here is the word PROPERLY. The cast part must be correctly heat treated and be free of internal defect. Internal defects in a casting are, in large part a feature of the design of the mold and the casting process. The casting producer uses x-ray analysis of cast samples to assure internal integrity. Acoustical analysis (analysing the stuck ring tone of a part will also assure quality). I compare the yield strength of my cast part against the yield strength of one of the arms of the spindle. The arm is a region of the forged spindle that was squished into the die and thus exhibits the maximum strength of the part. The cast part must have yield strength greater than the arm of the forged spindle.

Thanks everyone for your continued valuable input.

i would be fine with a high strength cast part. at any rate, a new high strength cast part is going to be less failure prone than a 40 year old forged part in most cases. IIRC, the last time this discussion came up you didn't want to get too far away from stock because of the smaller audience for this type of part, hence my recommendation to everyone to keep their suggestions for the design less complicated. i would really like to see this spindle made so i wanted to keep it as simple as possible to increase the chances fo it actually making production.

however, i can :Zip2: if you want.

 

[Helmantel]

Degins,

Interesting explanation on forging vs casting. Are the originals cast or forged? I always thought they were forged, but I think you said in another discussion they were cast? Not that it really matters, but I'm just curious. Knowledge is power, you know

Anyway, I'm no metallurgist, your explanation on how to make high strength spindles despite being cast sounds convincing to me

Arjan