ayellows2k

Hi everybody, i'm replacing a few control arm bushings and I have a question.

I'm replacing the front lower compliance bushing with Mugen hardened rubber ones. I'm just not sure what to replace the front lower bushing with (see #2 in this link on Powerflex's website: Honda S2000 Performance Suspension Bushings). Anybody know some good options?

If I replaced it with the poly bush from Powerflex, do I keep the oem metal shell from the old bushing or just press the whole thing out and then press the Powerflex poly in?

Lastly, what are your thoughts on mixing poly with rubber to get some compliance but also crispness? I was thinking of going with Powerflex race.

Thanks for your help

B serious

I am not really a fan of polyurethane bushings. Usually too much slop, too much harshness, and not much gain. You do get less binding than rubber, though.

I'd still rather use OEM (genuine honda) if I wanted it to last forever.

Or sphericals if I wanted response at the cost of some added maintenance.

ayellows2k

Ok, what are your thoughts on the Hardrace hardened rubber bushings that have the metal sleeve?

DefSport

Urethane bushings are horrible as a suspension rotational bushing. They are stiffer than rubber, yes, but they cause a huge amount more friction in the suspension movement vs a rubber bushing (which acts more like a spring, with a little internal friction). Urethane is no spring, all friction, and a ton of it at that.

This causes your bushings to translate suspension movement directly into the car rather than letting the damper absorb the impact/movement in a controlled manner.

Spherical bearings remove bushing deflection without all the friction. Which is the way to go if you want to go higher performance and give up a little impact absorption.

Mccormick009

Im a bit lost on your rationale. How is a spherical more compliant than urethane?

powerflex and certain urethane bushings have lubricated sleeves that move freely (less than spheical) with suspension travel. Being a polymer (some softer than others) it has some compliance.

Sphericals have zero deflection but completely free articulation. I would assume they feel more smooth than anything but transmit all force to chassis with no buffer

Car Analogy

Urathane bushings, even when properly lubed, have a considerable amount of Stiction, static friction.

So while they react more smoothly and articulate better than rubber when there is a large impact, they react with no articulation to small impacts.

The results is a rougher ride overall, but better over large bumps.

Urathane bushings work great in big, heavy cars such as muscle cars, where you are dealing with a lot more force on the bushing even over small bumps, as it will overcome the stiction over surfaces where it wouldn't on a car like ours.

DefSport

The thing with urethane bushings is they actually ride OK over rough surfaces right after install, but they quickly pound out the grease after install and you're left with a ridiculous amount of friction over small AND large bumps. The small bumps just feel worse because sometimes the movement doesn't even break the higher static friction value (dynamic "moving" friction is probably half static friction) - such that almost all the bump force is translated into the body of the car via the "locked" bushing.

You can regrease and they're good again for a short while, but it never lasts. I've also not had good experience with zerk fittings for regreasing the bushings. It helps some, but it doesn't really coat the ENTIRE sleeve, and even a little unlubed urethane has a huge amount of friction compared to a rubber bushing.

DefSport

You're confusing radial compliance with high friction causing binding.

Yes, a urethane bushing has more radial compliance than a spherical bearing, but it has WAY more friction. This "locks" up the bushing and translates a large amount of force directly into the chassis instead of letting the wheel move up and down and letting the damper absorb the impact.

A spherical bearing has no impact absorption/radial compliance, but what it will do is let the spring and damper easily move and absorb the impact force. Yes, some sharp hits like reflector dots etc. translate more impact harshness into the unibody with sphericals because the impact is so sharp, but over typical road bumps, the spherical bearing is great at letting the spring and shock easily absorb all wheel motion.

Slightly stiffer rubber than OEM is actually a really good bushing material for a street car, and maybe sphericals in a few places to limit wheel deflection under load.

Singh_snisen

Do spherical is ur a baller or just do mugen on all arms.

andrewhake

This is my plan for my own car. Fresh arms with spherical compliance, slightly stiffer Mugen/Spoon rubber bushings for rest of the arms. And spherical on the front upper arms (Ikeya Formula adjustable arms) to improve steering feel a bit which are already on the car and work very well.

Porsche does this selectively on all of their more motorsport derived cars like GT4, and GT3. Using spherical where it makes the most sense, and stiffer rubber in other areas.