Urethane Control Arm Bushing - What brand?

[housegsx]

Ok autocross/road race guys, what brand suspension bushings should I go with? Prothane or Energy Suspension? What do you use? I hear Prothane is has a harder durometer than Energy Suspension. Is that true and is that preferred? Is there anything else different about these kits that I should know? I've read Prothane have a split design. I don't know what that means, it might just be referring to the engine mount bushings, which I don't care about.

 

[viprez586]

Polyurethane is polyurethane... I highly doubt there is any difference.

 

[AndrewD5418]

Polyurethane is polyurethane... I highly doubt there is any difference.

One would think. Ask Tim Zimmer about his front/rear motor mounts.

 

[housegsx]

I have no interest in motor mounts. I've already done those. I'm only concerned about upper and lower control arm bushings, front and rear.

 

[awdfun]

If you really want to replace ALL of them in the back, get the Prothane full kit, as the Energy kit doesn't come with the 4 inner bushings you'll need.

 

[turbosax2]

The general consensus is that Prothanes are stiffer than ES. If you want to verify this, email both companies and ask the durometer of the bushings. Prothane at least should answer for you - they told me the durometer of their motor mounts. The Prothane "split design" means that the bushings are two pieces and will install like their motor mounts do. The ES bushings are 1 piece and will be a little tougher to install, might have to have them pressed in.

Remember, RRE and Dennis Grant don't recommend replacing the bushings on the front lateral arm with polyurethane.

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Far North Racing - A-Arm and other stuff


Assuming you don't need the sway bar bushings or shock bushings because you have aftermarket sway bars and shocks, you can save some money by only purchasing the bushings you need.

Front Control Arm Bushing Kit, Upper & Lower - 13-201 - $41.39
Rear Control Arm Bushing Kit, Upper & Lower - 13-301 - $116.39
Front Shock Bushing Kit - 13-901
Rear Shock Bushing Kit - 13-902
Sway Bar Bush. Kit, 19mm Bar (FWD & AWD) - 13-1101
Sway Bar Bushing Kit, 18mm Bar (AWD) - 13-1103
Total Kit - 13-2001 - $179.95

Prices found here:
MITSUBISHI, 1997, Prothane Motion Control - summitracing.com

 

[housegsx]

If you really want to replace ALL of them in the back, get the Prothane full kit, as the Energy kit doesn't come with the 4 inner bushings you'll need.

Which 4 inner bushing? Do you mean on the lower arms?

The general consensus is that Prothanes are stiffer than ES. The Prothane "split design" means that the bushings are two pieces and will install like their motor mounts do. The ES bushings are 1 piece and will be a little tougher to install, might have to have them pressed in.

Yeah, I've heard Prothane is stiffer. At least for the motor mounts. Can you explain to me what split design means? Is that inferior to the ES design? Or is it just as good, but aids in ease of installation? Where are they "split"?

Remember, RRE and Dennis Grant don't recommend replacing the bushings on the front lateral arm with polyurethane.

I didn't know this. Why would Dennis not recommend polyurethane and then proceed to use spherical bearings on the lateral arms?

Assuming you don't need the sway bar bushings or shock bushings because you have aftermarket sway bars and shocks, you can save some money by only purchasing the bushings you need.

Thanks, I may end up buying them separately. I don't need engine mounts, shifter bushings, or sway bar bushings. I've already done those.

 

[turbosax2]

The split design just aids in ease of installation, I don't see why either split or 1 piece could be called "superior".


Split design. This picture shows 2 bushings. They are each 2 pieces, so you put one piece in one side of the control arm, and the other piece goes in the other side (just like the motor mounts).

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1-piece design. Look at just the red bushings. They're only 1 piece so you will have to press them in.

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Quote from DG's site:

But it's not enough to just hog out a solid bushing and press that in there (or use a polyurethane bushing) as the suspension MUST pivot or the steering won't work. The solution is to press in a pair of spherical bearings. These are solid radially, but allow the arms to swing free.

Apparently the polyurethane won't allow that arm to pivot like it needs to. I would think the spherical bushings are probably worse for shock noise and wear than the polyurethane bushings, but that's the sacrifices you make for a race car. I'm pretty sure I've seen a quickie how-to on installing the spherical bushings - if you're interested I'll try to find it again.

 

[housegsx]

Quote from DG's site:
But it's not enough to just hog out a solid bushing and press that in there (or use a polyurethane bushing) as the suspension MUST pivot or the steering won't work. The solution is to press in a pair of spherical bearings. These are solid radially, but allow the arms to swing free.


Apparently the polyurethane won't allow that arm to pivot like it needs to. I would think the spherical bushings are probably worse for shock noise and wear than the polyurethane bushings, but that's the sacrifices you make for a race car. I'm pretty sure I've seen a quickie how-to on installing the spherical bushings - if you're interested I'll try to find it again.

Thanks! Ok, I know what the split design is now.

To me, that quote from Dennis' site seems to suggest that polyurethane isn't good to use anywhere in the lower control arms. It doesn't say that it's bad to use just where the shock fork mounts.

Also, I've thought about spherical bearings, but I don't know about going that route for a car that still sees street use and doesn't run race rubber on the track yet.