ES bushing epiphany.. something im sure yall already knew.

[90kacoupe]

When i had the subframe out of my car and all the suspension peices apart.. i didnt put any of my ES bushings in the uprights or the LCA's.. the reason i didnt is because the stock bushings were stiff enought.. but after messing with my suspension with out the shockson. (moving it up and down) i realized i need to press those bushings in asap.. and here is my reasoning.. and correct me if im wrong..

with the stock bushing the metal sleeve in the center is made into the bushing.. and in the ES they are not.. so when u tighten down ur stock bushing it pulls the metal sleeve tight. and when ur control arms move it fights the rubber in the bushing the whole time, limiting the movement. with ES bushings the metal sleeve is seperate so when the control arm moves the metal sleeve will turn inside the bushing instead of trying to twist the bushing..

im sure yall already knew this, but i felt like i made a decent discovery.. lol and correct me if im wrong on any of this..

[a_ahmed]

welcome to the real world mr. neo...

haha jk :P That's why rubber bushings rip and suck, not that polyurethane are an excellent alternate in contrast to spherical solutions.

[90kacoupe]

lol yea this is something im gonna do on my s13 subframe for now since i have all the parts.. but when i do the s14 subframe swap.. everything for it will be spherical bearings..

[Def]

I'd avoid the urethane bushings for our rear uprights.

Urethane is a very high friction material against metal, and you can grease the crap out of the metal sleeve and it'll rotate with moderate friction when you first install it. A few weeks/months down the road, and almost all the grease will have squeezed/run out, and you'll essentially have an almost unmovable link generating a huge amount of friction whenever your suspension tries to actually move(which is the whole point of a suspension).

Stock rubber bushings act more like a spring which is not ideal as they're variable with suspension travel. The rubber also has lots of internal friction, so they're not completely frictionless.

Bottom line - friction in your suspension is bad. In an ideal world you'd have zero friction in all your suspension links.

Spherical bearings are king in eliminating friction AND eliminating compliance/deflection, stock rubber bushings are way behind in the friction category, and probably worst from a compliance/deflection standpoint. Urethane is lightyears WORSE than any other bushing solution with regards to friction, and only marginally better than rubber from a compliance standpoint. Overall I'd say spherical bearings if you can even possibly justify the expense(I'm working to make that jump a little more affordable), or keep the stockers.

Nismos would probably trade less compliance for more friction and more of that "hard to control" spring effect. Probably not worth the $$$ unless you really feel the tradeoffs are worth it and that's all your autox/race class allows.

[ecugrad]

Delrin?

I know that's gonna be a DIY kinda thing

[Def]

Delrin is a horrible bushing material really. It's only good in a class where you can't use anything else. I guess it gets rid of the compliance, and has less friction than urethane, but it's still really high AND they don't let things axially rotate, which is a must(i.e. turn left and right while rotating the pivot). So you end up with a ton of binding, probably more than our stock bushings with all the stuff going on back there.

E36/E46 M3 club racers only use them on the front control arm bushing that actually gets a benefit out of not axially rotating(keeps the wheel in the same position - kinda the same as us using rigid tension rods up front). Other than that, most have found them to be trash when trying to replace a complex bushing like pretty much everything on our car.

[racepar1]

The only bushings where delrin would work on our cars it the RLCA bushings as they do not need any axial movement, just radial, For that application delrin is actually a pretty good solution as it is impregnated with carbon, which makes it somewhat self-lubricating. I think urethane bushings are an order of magnitude better than the stock rubber ones, but still not anywhere near ideal. A good idea if you are installing urethane bushings is to install grease fittings so that they can be lubed regularly because like DEF said they lose lube and begin binding quickly.

[Def]

They likely are better than a stock bushing when well lubed. They quickly start sucking with tons of friction after that though. Grease/zerk fittings might be an option - but at that point with the effort involved I think there are better options. Keep in mind you'd probably be looking at weeks to maybe a few months max between greasings - and the mess that would follow as it's pushed out.

[racepar1]

Ya but a good spherical bearing is going to run at least $50 each and there are 16 bushings in the rear suspension including the LCA bushings and 12 not including them. That works out to $800 for all 16 sphericqal bearings and $600 for everything but the LCA's. Beyond that you would have to machine up your own sleeves for the bearings as well as the spacers for them and if you don't put bearings in the LCA's you have to machine up some delrin bushings and some metal sleeves. Bottom line is that bearings are not an attainable solution for a lot of people. Installing some zerk fittings, greasing the bearings regularly and cleaning up the mess regualrly is much more realistic.

[Def]

Well, arms are cheap enough and satisfy the spherical part on one end, and I'll be offering some Aurora bearings for $100/pair, so I don't think it's a complete deal breaker when you're talking about putting a nice set of dampers on the car and other arms.

I've thought about delrin on the rear LCA, but I wonder how it'd work in practice. I agree sphericals in the stock rear LCA is probably cost prohibitive given how many of them there are.

[jmauld]

How often do spherical bearings need to be lubed?

Would Delrin work in the front Control Arm, with the stock (or nismo) rubber bushing in the T/C rod?

[Def]

How often do spherical bearings need to be lubed?

Would Delrin work in the front Control Arm, with the stock (or nismo) rubber bushing in the T/C rod?

Never if they have PTFE liners(all should for use on cars).

Nope, even with sphericals the control arm has some rotation due to the tension rod being bolted to it. On stock/Nismo bushing arms the front control arm is going to be moving around like crazy.

[jmauld]

How much movement are you talking?

Where I'm headed, is that I don't know how much play would be allowed by a polyurethane/delrin bushing that is only ~4mm thick (working off of memory here).

On the flipside, I also don't know how much movement would be forced on the control arm by a T/C rod that is using a spherical bearing. To me, it always seemed like using a spherical on the T/C rod and not on the control was a bad idea. If you did one, you really should do both of them. At least, from the way that I understand their movement.

Do you agree, that in an ideal setup, the control arm would only move straight up and down? I assume that the angle on the T/C rod is an attempt to reduce the amount of push/pull that it has on the control arm as it moves in an arc?

[Def]

There is essentially zero give in delrin, a little bit in urethane.

The control arm gets rotated by the simple fact that the tension rod by definition(it is a rod) is straight from its bracket to where it mounts to the control arm. Move the control arm up and down and you can see that the tension rod will force the control arm to rotate as it swings in this arc. The tension rod cannot be in the "control arm is flat" position as it swings in an arc.

[Def]

As for ideal setup, yes, I think angling the control arm isn't optimal, but there isn't an even remotely easy solution to that that still involves the stock suspension mounting points. With sphericals everywhere the angling of the arm becomes a non-issue.