hornetball

iTrader: (4)

Yeah, that was a pretty bad threadjack, but the subject was worthy. Well done Curly!

bbundy

I made sleeves for urethane bushings that actually pivot. I replaced all the 7/8” OD sleeves with 4340 ¾” OD Sleeves surrounded by ¾” ID 7/8” OD SAE oil/Teflon impregnated bronze bushings. Rear upper is a spherical.

Don’t have any time on them yet but they feel great I think they will work well. Now requires very little force to move the suspension up and down now. Removed like 40 lbs of static friction in the rear. Performs very close to an all Spherical setup and probably less likely to develop slop as the surface area transfering load of the bushings is much greater than that for a sperical.

aidandj

iTrader: (5)

Where do I place my order....

bbundy

I did it it works wonderfully well!!

hornetball

iTrader: (4)

Dang, Bob, that's awesome. Were they OTS parts from an industrial supply house or did you have to machine yourself?

bbundy

Had the sleeves machined from cold finished bar stock that is typically used for hydraulic rams so surface finish looks smooth and polished like a shock shaft material. Bushings are from McMaster but the local hardware store has them as well. Material cost isn’t terrible it is a lot of machine time however. A little bit over 3 feet of bar stock to bore out and part off in some pretty tough material.

For the cam bolt locations I have 4mm thick 7/8" OD washers made so as to better handle high clamp loads without squishing the subframe which was a conscern.

aidandj

iTrader: (5)

Would you be willing to share dimensions, I may take this on as my next lathe project.

Mobius

iTrader: (2)

That's awesome Bob. Aidan I will donate fundage to the effort, I want a set.

aidandj

iTrader: (5)

Also just to make sure I understood it right, the sleeves have uerethane bushing inside them, which stop the binding issues, but create friction issues. By putting the sleeves inside brass bushings you are left with a bushing that doesn't bind laterally yet still can rotate freely?

Dustin1824

iTrader: (2)

I have wanted these for as long as I saw them in Sean's rear knuckle sperical bearing thread.

Just keep in mind, I believe Bundy made this to work with his V8R control arms. You would have to make custom urethane bushings that are 7/8" ID and standard miata OD for these to work.

Is this correct Bundy?

bbundy

These replace the metal inner sleeves that come with energy suspension urethane bushings or the version found in V8R arms. You still use the urethane parts. Urethane sliding on steel absolutely sucks for low friction properties and is hugely inconsistent and won’t stay lubed for really any use at all I don’t care what scheme you use. I would argue bonded rubber like OEM is a better solution to urethane because it has no sliding friction.

The bronze bushed inner sleeves in the urethane seems to cure the friction problem while retaining the advantages Urethane has over both bonded rubber and delrin solutions.

aidandj

iTrader: (5)

Ok that makes sense. For some reason I thought the sleeves you made went around the urethane bushings. So these go inside the urethane and the copper bushing is what slides inside the bushing.

So the sleeve just needs to have the same ID as the normal sleeves in the urethane bushing kit, and then the OD needs to match the ID of the bronze bushings.

What size bronze bushings are you using?

Got any installed pictures?

If the bronze bushing is the part sliding on the urethane bushing then why did you go for the $$$$ steel bar stock. Seems like any standard steel would work.

hi_im_sean

iTrader: (3)

i almost bought the isc offset uppers, then after researching, emilios past posts steered me away. i ended up taking his advice and make the front lower offset and couldn't be happier. with delrin in the front and rubber in the rear, binding isnt an issue

https://www.miataturbo.net/build-thr...9/#post1193050

i was going to make a thread a few weeks ago with all the dimensions of various bushings as i make them throughout the car, starting with the LCA front, but i couldnt find my napkin cad drawing in the garage.

hi_im_sean

iTrader: (3)

oddly enough, all the discussion on these was in my spherical knuckle thread, we talked about alloys for at least 3 pages i think

https://www.miataturbo.net/race-prep...cussion-82072/

aidandj

iTrader: (5)

I'll re-read all of that. It started to go over my head and I got bored at one point.

hi_im_sean

iTrader: (3)

its very dry

aidandj

iTrader: (5)

Just got started, its freaking death valley in there. I'll work my way through it.

aidandj

iTrader: (5)

Bob, with the bronze bushings will lubing still be required? How long do you think these will last? Will the bronze wear at some point?

bbundy

bronze press into the urathane slides on the steel.

aidandj

iTrader: (5)

Ok so the sliding surface is the steel sleeve and bronze bushing, that makes more sense.