[GI] Poly bushings: Making a Comeback in Feb 09'!!!

[onlytrueromeo]

^I was going to suggest something like that....I like!

If for some ODD reason, they can't cast it like that, or drill it like that or w/e, maybe we can do something ourselves, such as thread an appropriately sized screw to thread the inner surface?

I know it sounds crude, but if we have no other options, would it work?

My other thought was that instead of grooving the poly, an either thing would be to do that to the metal insert. The only problem I foresee in that is that it might act as an abrasive and wear away at the poly.

[wytbishop]

^I was going to suggest something like that....I like!

If for some ODD reason, they can't cast it like that, or drill it like that or w/e, maybe we can do something ourselves, such as thread an appropriately sized screw to thread the inner surface?

I know it sounds crude, but if we have no other options, would it work?

My other thought was that instead of grooving the poly, an either thing would be to do that to the metal insert. The only problem I foresee in that is that it might act as an abrasive and wear away at the poly.

It would be possible to create something like that on the finished bushing with a large tap, but I don't think it should be a problem castign that feature. I think it might increase the cost significantly though. I have sent an email to the shop forman to get his feedback on the design.

You're exactly right about grooving the sleeve. It would destroy the bushing in no time.

[MazdaManiacMx3]

The problem with that grooving is that there is less surface area contacting the sleeve therefore creating more room for it to flex and move ( what we are trying to stop by putting harder bushings in , in the first place .)
Thats only my thought on that anyways.
Kris -

[wytbishop]

Good question Kris. I have considered that. The trick I believe is to stike the correct balance between trapping the neccesary volume of lubricant and creating asignificant lubricated surface area, without reducing the stiffness of the bushing. The grooves I've drawn are only 0.025" deep. I haven't calculated it, but I estimate the reduction in surface area at around 13% without having the drawing to look at. I don't think that deflection would be too dramatic, but it can be reduced easily to around 10%.

I have just spoken with the shop forman and he says it's no problem to do, but may be costly. Obviously the more machine work that needs to be done, the more it costs to make. I will give him one complete drawing on Monday so that he can give me an idea of the cost versus other less detailed options.

[wytbishop]

Just as a progress report...

Models of the SuperPro bushings are complete. I will be removing the control arms from my parts car on Sunday. My wife will be away all week so I will be able to test fit the SuperPro bushings and identify any fitment issues or improvements necessary and get the drawings completed by the 25th. At that time I will nail them down as to a timeline for quoting and production.

[RS_OBD'oh_2]

Why is it that more things get "nailed" after the wife takes off?

Sorry, I went all Daninski on that.

[tehbrookzorz]

I will try to observe this thread! If you start selling them and I don't pipe up, remind me! I like all your ideas!

[wytbishop]

Updated top post.

[Flyer]

I are also the interested...

[wytbishop]

So yesterday I went and pulled the passenger side suspension components off the parts car. HOLY FECK what a job. the bolt which passes through the rear subframe was no problem cuz it was very new looking, but the spindle bolt was so totally siezed it had to be cut. If the spindles on the daily driver are that bad it could cause problems.

So I am going to press the bushings out today and beadblast the parts tomorrow I hope. This will allow me to test fit everything and evaluate some of the sizing options and stuff.

I sent a complete drawing of the rear front TTL outer bushing to the manufacturer to get them to tell me if they can be made to my requrested specs and how much that is likely to cost. If it's ridiculously expensive to do, I will have to re-evaluate my design.

[turbulence23]

damn man, those look s*xy

i'm interested in a complete kit, but would first like to know what the costs will be..

i just want a good replacement for the stock bushings, but not that hard that it wil shake out the fillings in your teeth

[wytbishop]

I have nearly finished generating drawings for the bushings. I have had to seek the advice of a professional draftsman for one key element which is delaying the process slightly. I am also still waiting to hear back from the manufacturer on another key question, so that's really what's holding things up. I determined that the set I bought had two incorrect part numbers in it. The rear trailing arm on other BG chassis cars is 35mm OD and ours is 44mm. Our rear LCA bushing is larger as well. Interestingly, the information on clubprotege.com is correct and does reflect these differences, so I don't know if he ordered the wrong parts, or if SuperPro sent him the wrong stuff or what. Either way, I have straightened it out and this wil be the definitive kit for A-spec MX3's.

I have figured out endlinks. I am going to order a set of 3.25" links from AWR for the Probe/MX6 and make sure that they fit for the rears. I have a catalogue coming from a Canadian manufacturer of the spherical Heim joints and associated parts and I know which parts I need for the fronts, but I have to wait to get the catalogue to get part numbers and then contact them for pricing. I can get it all from the US for about $40 each link so I hope to be able to do about that same price or better in Canada. If they have a distributor near by, the savings in shipping will make a difference. The front links are tough because they're about 2.25" from center to center. Nobody makes a link that small and the standard parts have to be modified to do it at all.

I will order the parts I need to make a set and make the necessary modifications. Once I have made a working set of links I will contact Jeff about setting up a group buy. This is a much simpler task than the bushings so I will have no trouble getting that done by the time bushings are ready.

[Mooneggs]

I am definately interested in this for both of my cars! I will have to wait and see the part list as I may only be needing mainly rear components...

how will these bushings compare to the SRD front control arm bushings? for instance if I am already using all the SRD bushings would you recommend I switch them?

[wytbishop]

I don't know the Durometer of the SRD bushings. I will be asking the manufacturer to supply bushings in 70, 80 and 90 Shore A Durometers, so you should be able to get something that matches if you know what the SRD ones are.

I can only speculate as to the effect of using different Durometers front and back. I don't think it would be catastrophic. I think different bushings will have different affects on handling characteristics so it's really a trial and error thing. If you picked the brain of someone with lots of racing experience I'm sure they would be able to say this bushing should be stiffer for this application or that bushing should be softer...etc.

For myself I want a comfortable firm suspension for the street so my forst set will be all 70 Duro. Later I will build a set of suspension components which are stiffer for Autocross.

[wytbishop]

Well I've been having trouble getting concrete feedback from the manufacturer so today I went looking down another avenue to have these made. I talked to a company in Calgary which is not a plastics manufacturer, but a machine shop which specializes in mold making. I am sending them my models tomorrow to have them give me a quote to produce the molds for me. This method has benefits and detractors. On the upside, I would be flat out purchasing the molds from them and then I could take them to any place which works with poly and have the bushings cast. This way there is no question as to who is the owner of the product. Me. On the downside, I have to front the cost of the molds myself. I will get it back because it was always going to be incorporated into the cost of the bushings, but this way I will have to pay for the molds before I can have any bushings made.

We'll see how it goes. I think I like this way better, because later on I can just take my molds to whomever I choose and have more bushings made.

Anyway...just wanted to let you all know what's going on.