Bushing problems

[doug_porsche]

Nice.

i am still researching, obsessing, over the bushing issue.
i dislike the variable spring rate that the "stock" rubber bushings force on you.
monoball/spherical have the control properties and low friction I desire, but... The ride suffers, trying to keep momma happy, and on the street seem to wear quickly.
poly bushings are available, (and I should just finish the bushing removal tool, and finish installing the set I bought from you), but can squeak and possibly, over time allow the arm to shift forwards/backwards (problem like Ken had).

the current rabbit hole I am looking into is to "borrow" the IP that Elephant Racing uses successfully on Porsches with their Polybronze bushings. https://www.elephantracing.com/porsc...onze-bearings/

you do need to grease them frequently, (depending on the environment, monthly to bi-annually is what I read), but with the grease zerks , a 10 min task, addressing the longevity concern. The polyurethane addresses the vibration and alignment issue. The bronze shoulders would address the forward/backwards issue.

I just need to decide on material and check with my brother, a machinest (and the other 80% of my brain trust), to see if we have the tooling to pull this off (don't know if he/we can machine the grease channels with his cnc/lathe)

[gafernandez]

we do not have the space for the thick bronze required for the grease fitting.

I just road in a lotus with the same style spherical bushing i am proposing and it road no different than the stock ride

[GTO3KJ]

Admittedly my car only gets used on track but l converted it to spherical bearings and it's perfect, previously used poly bushes which l found were inconsistent.

[gafernandez]

How did you do the Spherical bearing

Does it seam to ride any different other than the handling

[doug_porsche]

Good point, as usual for you.
I did some shower thinking, (I know TMI), and came up with the solution that...
The bushing, with the shoulders, need to be two half's.
So I could move the grease fitting to the A-arm its self and just pocket where the fitting would extend.
Then I forced it through the KISS filter and though; if I just would make each half 21ish mm, that would give me approximately 3ish mm space gap where the fitting could extend into, and give me a 3ish mm grease reservoir.
Then I forced that idea through the KISS filter and though; if I would just trim the shoulders off the polyurethane bushings, and then use either a "Bunting bearing" washer or a plastic self-lubricating bushing, to replace the shoulders, then I would have a simple, captive (fore and aft) solution that even I have the technical skills to implement. (and thanks to you, I already have the poly bushings).

[gafernandez]

you mean something like this, was already working on it but urethane bushings were out of stock should be here tomorrow to see if they work

were the grey is the a arm, the gold is the metal part of the bushing and the red is the urethane

[doug_porsche]

Long answer
If it outer metal barrel is a press fit, to prevent fore and aft movement, then yes.
Or, for easier maintenance , replace some/all of the poly shoulders by extending the metal barrel to include a shoulder. (Again wanting to capture the bushing, preventing the "Ken" fore and aft movement issue.
This could aid installation by eliminating the need for a press to assemble the bushing, by reducing the OD of the outer barrel by a couple of thousands and you could assemble, and added bonus dissemble, buy hand.


Or again, KISS, delete the polyurethane shoulders, replacing with a bronze or plastic bushings, one per side.


short answer
yes!

[gafernandez]

what i found is that the sholders are sheared off by the arm so the idea is to internally support the lateral movement instead of trying to do it all on the lip

[doug_porsche]

what i found is that the sholders are sheared off by the arm so the idea is to internally support the lateral movement instead of trying to do it all on the lip

“Learn from the mistakes of others. You can't live long enough to make them all yourself.”― Eleanor Roosevelt

So your design is a press fit. Cause and effect riddle answered. Thanks for sharing the knowledge.

[doug_porsche]

Do you have an opinion on...
i am tempted to try a solid delrin bush in just the rear tow arms.
i don't think it will transmit too much nvh, weare should be minimal because of minimal rotational movement, compared to the a-arm bushing.
i don't think the temps will get too high to cause an issue for delrin.
Will lock in toe settings.
quick and easy to try.