The Miata Bushing MEGAthread: Heirarchy, DIY delrin dimensions, info and discussion
A heads-up for anyone running Superpro poly bushings - the poly bronze retrofit kit won't fit. Fortunately I discovered this before Sadfab shipped the kit, and I have now upgraded to the delrin.
In fact, anyone running polys not mentioned by Sean should check the bore diameter before ordering, and make sure ALL the diameters line up with the bronze dimensions.
In fact, anyone running polys not mentioned by Sean should check the bore diameter before ordering, and make sure ALL the diameters line up with the bronze dimensions.
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A heads-up for anyone running Superpro poly bushings - the poly bronze retrofit kit won't fit. Fortunately I discovered this before Sadfab shipped the kit, and I have now upgraded to the delrin.
In fact, anyone running polys not mentioned by Sean should check the bore diameter before ordering, and make sure ALL the diameters line up with the bronze dimensions.
In fact, anyone running polys not mentioned by Sean should check the bore diameter before ordering, and make sure ALL the diameters line up with the bronze dimensions.
Poly/bronze has been verified to fit Energy Suspension and Prothane kits. Im almost positive Whiteline uses the same diameters, but im not 100% sure as I have never had a kit in my possession.
I bought some Whiteline bushings for trailing arms in my 323 GTX. The steel sleeves in them were not metric. 3/4" material on one end 1" on the other. I believe Whiteline is an Australian company that has there parts made in Vietnam kind of shocked to see inch sizes. I though SuperPro was Australian as well. Energy Suspension and Prothane are both US companies and I think made in the USA as well.
Last edited by bbundy; Apr 1, 2016 at 01:49 PM.
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Thread Starter
Joined: Sep 2012
Posts: 4,560
Total Cats: 1,143
From: your mom's house phoenix, AZ
I must be completely confused. Lol, it happens from time to time.
So Prothane, or ES. All others are on their own and can follow madjaks lead if they choose.
So Prothane, or ES. All others are on their own and can follow madjaks lead if they choose.
Straight 3/4" on the camber bolt locations seems like a bad Idea. Even the energy suspension 7/8" ones come out mushroomed on the ends because of the adjustment slot interface lack of contact area.
Joined: Apr 2014
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I'm running 1" sleeves in my camber locations. First track day on them is tomorrow. What do you torque them to Bob?
If I were to guess I would agree with Bob. I bet they are not metric.
If I were to guess I would agree with Bob. I bet they are not metric.
for the ends on the bronze bush cam bolt locations. should work perfect.
The Official ARP Web Site | Kits
The Official ARP Web Site | Kits
I don't remember exactly. I do go over factory torque spec. but that's how I keep them from moving.
Thread Starter
Joined: Sep 2012
Posts: 4,560
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From: your mom's house phoenix, AZ
for the ends on the bronze bush cam bolt locations. should work perfect.
The Official ARP Web Site | Kits
The Official ARP Web Site | Kits
I also got some 1144 rod turned ground and polished from speedy metals. seems like it should have enough yield strength, a nice smooth surface finish, and way easier to machine than most other high strength choices.
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I was thinking about your issue with the ES sleeves deforming. To be fair they are made of some sort of cheese steel. The stuff just seams really soft, like I said, I think its 1008. I have 4 new ES sleeves i might go cut on the lathe for some more anecdote.
And yea, 1144 is nice to machine. Small cuts, its like cast iron, larger cuts, its like a harder but non-sticky aluminium.
And yea, 1144 is nice to machine. Small cuts, its like cast iron, larger cuts, its like a harder but non-sticky aluminium.
Last edited by hi_im_sean; Apr 2, 2016 at 05:42 PM.
Here's what I am working on.
I went with precision ground 416-A stainless for the sleeves. Super easy to machine, great surface finish, and not all that expensive (under $50 for all of the material I needed). I bought 6" of 5/8", 36" of 3/4", and 6" of 7/8" to make everything. Yield strength is 60 ksi which is pretty good, and you could harden them if you had the means (I don't). Took me about 8 hours of work on the lathe to make all this crap though!
Instead of bronze I am using precision Delrin tubing bought from McMaster. It's about 1/4 the cost of bronze, and you can make the bushings one piece because you can cut the tube to whatever length you want. The tolerances are surprisingly good.
I decided to use the ES front upper sleeves as-is, rather than trying to drill out the urethane to fit the 7/8" OD delrin. Later on I might just go with a solid delrin bushing in this location instead. We will see.
I also bead blasted and painted all of my control arms with 2K primer and 2K paint. All of them are tapped for zerks as well. I might cross drill some holes in the delrin bushings to at least have somewhat of a chance of getting grease between the delrin and the stainless. However they are such a close fit and the surfaces are so smooth on each that I doubt the grease would really get in there anyway!
Time to go assemble all of this, and install my brand spankin' new Xidas with spherical tophats at the same time!
I went with precision ground 416-A stainless for the sleeves. Super easy to machine, great surface finish, and not all that expensive (under $50 for all of the material I needed). I bought 6" of 5/8", 36" of 3/4", and 6" of 7/8" to make everything. Yield strength is 60 ksi which is pretty good, and you could harden them if you had the means (I don't). Took me about 8 hours of work on the lathe to make all this crap though!
Instead of bronze I am using precision Delrin tubing bought from McMaster. It's about 1/4 the cost of bronze, and you can make the bushings one piece because you can cut the tube to whatever length you want. The tolerances are surprisingly good.
I decided to use the ES front upper sleeves as-is, rather than trying to drill out the urethane to fit the 7/8" OD delrin. Later on I might just go with a solid delrin bushing in this location instead. We will see.
I also bead blasted and painted all of my control arms with 2K primer and 2K paint. All of them are tapped for zerks as well. I might cross drill some holes in the delrin bushings to at least have somewhat of a chance of getting grease between the delrin and the stainless. However they are such a close fit and the surfaces are so smooth on each that I doubt the grease would really get in there anyway!
Time to go assemble all of this, and install my brand spankin' new Xidas with spherical tophats at the same time!
Another thing that is odd if you are making kits for people with V8R rear Uppers. all the bushings in the rear upper are 2mm longer than stock or anybody else. 58mm instead of 56mm. it requires spreading things a little on the chassis to squeez them in. I made them 56 and they were too narrow had to add length otherwise too much squish and friction.

More data The Whiteline catalog lists their inboard lower sleves as 19mm which I think might actually be 3/4". Their non adjustable front upper is listed at 22.2mm which I think is 7/8" and they don't list any parts for other locations. their offset front upper uses 3/4"
Last edited by bbundy; Apr 3, 2016 at 11:51 PM.
Another observation based on some Prothane universal bushings I got for another car.
I think Prothane material is significantly harder than all the other manufacturers probably half way to the hardness of delrin.
I think Prothane material is significantly harder than all the other manufacturers probably half way to the hardness of delrin.
Prothane is supposed to be 80 Shore A for all locations except for the front uppers where its 95 Shore A. 95A is about 50R and most delrin is 120R. For comparison.
I can't find any data listed about what they claim hardness is from anybody. All I know is the 19-602 bushings I got for lateral links on my GTX are way harder than any of the ES, Superpro, or Whiteline bushings I have. Feel real close to my 95A wheels on my skate board.







