SADFab

/\ Don't even need that. ES publishes the dimensions of the sleeves in every kit that I have seen. Its even in the instructions. I could simply look up the ND kit info, order the proper bearings per the dimensions and cut the sleeves to those dimensions with a few considerations and changes for locations that have alignment bolts for example.

k24madness

iTrader: (6)

Sean would you venture out to another marque? The 993/964 Porsche crowd favors walrod poly LCA bushings. They do however suffer the same fate as other CA poly installs. I can put you in touch with a distributor of the bushing who would buy in bulk. Maybe you guys could work something out.

hi_im_sean

iTrader: (3)

Pending some changes to the way we manufacture these, yes, definitely.

acedeuce802

iTrader: (1)

Does anyone know if the sleeves in the ES kit are made of reasonably machinable material? Has anyone just taken 1/8" off the diameter of the sleeves that come in the kit and add the bronze bushings? Is the washer necessary? I would assume that bronze bushings would still stay constrained in between the control arm tabs without the washers, or does the washer provide any other purpose? I read the thread so forgive me if I missed this already!

aidandj

iTrader: (5)

One of the issues with that is how thin some of the locations have to be, and the Es material is of somewhat questionable strength. All of our sleeves are made of stronger material that the ES sleeves.

Leafy

iTrader: (1)

You guys really need to buy a clapped out swiss machine fo cheap.

hi_im_sean

iTrader: (3)

Yes... Something like that. We are partial to haas.

I have. It is some of the softest **** steel ive dealt with. The washer is necessary to provide proper surface area to sustain the clamping loads at the alignment bolt locations.

Leafy

iTrader: (1)

Lol HAAS. I mean they're cheap and completely capable of making these. Swiss does have the downside of requiring you to buy precision ground stock, but then you really wont have to screw with the OD. Old clapped our swiss go for cheap typically because joe bumblefuck is scared of them because they think its too hard to run. But they're just lathes where the Z axis is the part moving instead of the tool turret, every single one has a free bar feeder, lol. A diy bar magazine is easy to whip up and then you can let that bad boy run lights out cranking these things out assuming you put good tools in it and get learned good on your part count per tool.

hi_im_sean

iTrader: (3)

The thing is, whatever we get won't just be used to make simple sleeves and T bushings. Im not going to divulge my business dealings in a public forum to justify it to you, just understand this isn't my first rodeo. Although I do appreciate your input Jonathan.

PAdutch

I am currently making my own set of delrin bushings for a NA CSP autoX miata (much thanks to SADfab for making the dimensions public) . I was going to use a offset FLCA-f bushing but I am concerned I will be losing caster. It would seem best to maximize caster and camber to put the offset bushing in the FLCA-r position. Am I missing something?

For reference, CSP autox means 15x10 or 11 wheels with 275 hoosiers. Stiff springs and cut fenders.

Godless Commie

iTrader: (2)

Just to answer the NVH and daily usage questions by a number of posters here about an all Delrin bushing setup:

They are great on a daily driver.
Yes, the car is more "crisp", but it's not harsh, at all.
I am using 7&6 Kg springs, and the car feels much smoother since I switched to Delrin.
Turn in is much better, and steady state cornering is a lot more fun.

Here are a couple links to my setup:

https://www.miataturbo.net/suspension-brakes-drivetrain-49/diy-offset-delrin-bushings-rear-lcas-camber-correction-74732/

https://www.miataturbo.net/suspension-brakes-drivetrain-49/clunk-rear-takeoff-75495/

I do have a couple questions for @aidandj

I noticed you are using one piece bushings (Delrin) for several locations.
I have made a point of making 2 piece bushings for all locations. That way, I have "lips" on both ends, because I treat all surfaces as thrust surfaces, and want to be able to eliminate friction.
What was your decision making process for 1 piece bushings?

Also, I leave a 5 mm gap between the 2 piece bushings. That is my location for the grease zerks and I fill that void with grease, obviously.
I grease my bushings about once a year, more if I have the time. I have not seen much dirt come out, if any.
I looked at your drawings, and you leave no.space between the two piece bushings. Any special reason?

On a side note,I made a set of engine mounts and made (cast) my own bushings for those out of Shore 57A PU.
Love them so far.
I only have 200+ Km (120 miles) on the car since I installed the motor mounts (with the rebuilt engine).
They seem to make a noticeable difference in throttle response.
Plus, they look cool.

hi_im_sean

iTrader: (3)

Since I designed the bushings, Ill go ahead and answer.

I only use a 1 piece bushing where there is a bolt going through both for and aft bushing locations on a given arm. This would be the FUCA, and RLCA-O.

FUCA-
1.There is no inner thrust face period. The bolt passed through a tube in the subframe, which is around the same diameter as the steel sleeve. So you would have to add a washer to make a thrust face for the flanges that would face each other.
2.. There is little relative load on this arm, 1 thrust face is fine.
3. Assuming you did #1, you would have to machine the sleeve length specific to each car. Alternatively, you could make sure that the sleeve bore lengths are within a few thou of each other, and that the gap between them is the same, minus flange thickness, as the mounting point width. And that whole stack-up cant exceed a few thou. Delrin is not squishy, so in order for the rear facing or front facing thrust surfaces to both take a their full load, you would have to fit them to each arm so there is probably around a 0.002" gap. There is too much variation in arms and subframes, and they are definitely not within 0.002" in any dimension. If not, one thrust surface will makes contact first, and the arm will have to bend the amount of the difference between sleeve length and flange gap on the other bushing before it make contact, and even then they are very unequally loaded. Never mind the fact that would make things kind of tight and a pita to install for the end user, for almost no benefit. This is true of all locations, and one of the benefits of running poly in each lower is that it mitigate this on the arms that carry the majority of the loads on the car (the LCAs).

RLCA-
1. Same as above, a washer would need to be added. Energy does this in their kits, but thats poly. It will tolerate inconsistencies in the arm dimensions and squish to where it needs to be.
2. Same as #3 above with the caveat that this location is heavily loaded longitudinally. This was a concern of mine when I first designed these, but it has yet to become an issue.

Our bushings do have a space. Its just closer to 1-1.5mm instead of 5mm. Delrin doesn't need a grease reservoir, although it can benefit greatly from recesses that run axially, not radially. This is according to Dupont, the "inventors" of delrin, from thier PDF on how to implement acetal as a bearing. The idea being, that they serve as debris catches and give it a path to escape(debris refers to tiny metal particles from the sleeves and dust, or asperites broken off after break in). The only way to do that is with a broach, or have them injection molded. The former I refuse to do, and I dont have an injection mold setup. So I prefer to have the bearing surface area over a grease res that doesn't serve much purpose. And as far as the grease fitting, you just drill through the delrin and it gives the fitting much more to bite into than just 1mm of steel.

Godless Commie

iTrader: (2)

Thank you for taking the time to respond.
And, sorry for not directing my questions to you.

If you had a chance to look at the links I provided in my initial post, I'm sure you noticed I made my set back in 2013.
I have had one minor issue so far, and that was due to incorrect outer diameter for one steel sleeve. That has been corrected.
(Sleeve outside diameters need to be as wide as possible - not too wide where you end up with too little delrin material tho - to spread the loads to a wider delrin surface, things work smoother that way.)
Other than that, they have been absolutely flawless.

I completely understand your approach for the FUCA design.
To be honest, I think I will be modifying my drawings to convert them to 1 piece bushings.

As for the RLCA, (outers, sharing that big bolt) I really think sticking with a two piece setup would work best there for the loads imparted on them as you mentioned.

Also, what do you think about the spacers I came up with on the RUCA inner bushings?
I felt like I had to go in that direction after seeing how much the stock bushings "travel" under load.

EDIT

What do you think about offsetting the FUCA to gain max caster?

What I mean is this:
There is an 11 mm difference between the chassis mount tubing length and the distance between the two FUCA bushing holders.
You would normally split that difference and allow 5.5 mm on both sides (facing the chassis mount) to center the FUCA.

Now, if one were to move the FUCA towards the front by splitting that 11 mm difference like, say, 8 mm front and 3 mm rear, that would angle the upright towards the front at the top, yielding more caster.

I can never get the prescribed 5.5 degrees, best I can get is around 3 degrees or so.
Would such a modification be helpful, or am I missing something here?

Paging @hi_im_sean

Sorry for all these questions, but it's damn near impossible to find anyone I can talk about this stuff.

hi_im_sean

iTrader: (3)

Whoops forgot to answer this the other day.

Yes you are missing something, although its hard to visualize. Try to imagine how the LBJ moves in space as you take either the for or aft bushing position and move it laterally, while the arm rotates about the other bushing. Because that's what you are doing with the offsets. The front offset moves the LBJ out, almost in a straight line(its actually an arc, as it pivots around the rear bushing, but with very little longitudinal displacement (decreasing caster) as the arm is about a 90* L and the arc is just faling off the tangent point.... make sense?) away from the car increasing camber. If you were to offset the rear bushing, moving the rear bushing eye out, pivoting on the front bushing, it would move the LBJ forward (again, it travels in an arc with the radius being the distance between LBJ and bushing center points, so there is some lateral displacement too, actually decreasing camber a little bit), increasing caster and doing nothing for camber. If you make both the front and rear offset, you now have camber again, but just negated any caster gain, with the addition problem of having delrin in both positions where you need to have 1 poly (unless you get an offset poly from superpro AUS), although it would eliminate the almost insignificant loss in caster from the front only being offset.

clear as mud?

hi_im_sean

iTrader: (3)

I saw you earlier, just a bit busy this am. Give me a few and ill respond.


And wtf you doing on our schedule. You work nights?

hi_im_sean

iTrader: (3)

A broach I made to produce axial grooves. Its just too labor intensive to do...

Godless Commie

iTrader: (2)

I am Turkish, residing in Istanbul, Turkey, 10 hours ahead of you.
I do keep late hours tho.

Godless Commie

iTrader: (2)

I don't know what happened with the links, here they are:

https://www.miataturbo.net/suspensio...rection-74732/

https://www.miataturbo.net/suspensio...takeoff-75495/

Let me throw this in here, too.

https://www.miataturbo.net/suspensio...ive-pro-80290/

PAdutch

Very clear, thank you.

I am coming from a Macpherson strut car, where I used to run alot of caster 6deg+. Having alot of caster allows you to run less static camber because of camber gain. This, in-turn, has better contact patch under braking and can increase your ultimate turning grip.

I guess I need to do more research on set-ups but I was thinking getting camber is easier than caster. I will be running a extended lower ball joint already and if I needed more static camber I could always make offset FUCA bushings (I may have to run a spacer for wheel clearance, no biggy).

I guess I curious about a setup like this:
Offset FUCA (adds camber)
Extended Lower balljoint (adds Camber)
Offset FLCA-R (adds caster, slightly decreases camber)
Poly FLCA-F

I'm not sure where that would leave you as far as alignment specs but Ill be doing some more research. Seems like to much caster can lead to corner jacking and bump steer issues possibly.

Godless Commie

iTrader: (2)

Given the amount of suspension travel, bushing ends obviously rotate just a couple degrees.
Wouldn't that require at least 10 or more "grooves" to properly clean the rotating sleeves in there?