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But now I'm wondering if the rear control arms are the main source of the really hard ride. Would any of the other bushings contribute heavily to that? (Watt's Link, Front Control Arms, Sway Bars)?
I replaced them ALL with polyurethane when we did the rebuild, but I'd rather not re-do them all if I can help it so I'm kind of looking for most bang-for-buck in terms of smoothing out the ride.
Cheers,
Jon
Last edited by vipernicus42; May 9, 2022 at 07:04 PM.
Reason: I'm an idiot - the "Rear End Link" bushings I posted were for the swaybar end links and not the control arm links.
If you replaced the rear link bushing with poly, that is probably whats causing your harsh ride. What else changed? Stiffer springs too? I have poly in the control arms, front sway and torsion bars and in the rear watts linkage with stock rear arms (old as sin too) and the ride is only a little stiffer with the RB springs (which I cut a bit to adjust ride height).
The Springs and shocks are basically the only things that didn't change. I'm still running the RB springs and KYB shocks combo I've enjoyed for years. I think I also had one if not both RB Swaybars, I can't remember if I only swapped one waaaay back when I did the rack and pinion conversion, or if I had done both.
But since we had stripped the whole car down to bare metal for the big paint and bodywork rebuild project we replaced ALL the bushings with brand new poly. Control Arms, Watts Link, Sway Bar Bushings and Sway Bar End Link Bushings, front control arms, tension rods, you name it. If it was rubber and existed under the car we replaced it with brand new poly.
I regret that. I use the car for road trips and meets way more than I do for autocross (and I've never taken it track racing). A bit less kidney-jarring on these crappy local roads would be nice.
After a lot of research right here on the forum, here's what I went with which provides good road handling and still a soft enough ride in the rear that my wife-unit will go out in it with me.
On the rear, it's well-known that polyurethane bushings in the upper and lower control arms result in harsh ride and binding under certain corning conditions which results in ZERO suspension when it happens. Binding of the links will result in the car feeling like its bolted to the ground, and youll feel every bump in the road through your spine and neck. For this reason, stock OEM rubber bushings vulcanized into the stock arms are the right solution for a street car driven on typical roads. Keep in mind that you need to lower the full body weight onto the axle and springs before you tighten everything down on your upper and lower control arms, or you add pretension which will rip the rubber bushings away from their mounts. Also, cutting bump stops even on a car running older springs will vastly improve ride and handling, as sagging springs will quickly bottom out on the bump stops during hard cornering. Nothing drastic, just cut an inch off of each side. I run poly sway bar bushings, stock Watts Link bushings and OEM arms and added the double shear backer to the Watts Link and like the way it feels.
On the front, polyurethane tension rod bushings help to keep toe and camber aligned, while stock OEM control arms inner bushings will ensure a compliant ride quality. Sway bar bushings of polyurethane and end link bushings also work well to reduce body lean. Other than that, using OEM rubber bushings makes sense on hose arms which provide the most feedback to the driver. On a track this may be useful, but on the street it results in harsh ride and uncomfortable passengers. Plus, polyurethane bushings tend to be noisy.
This is excellent info. I had planned on doing just like vipernicus and going all poly so I wouldn't have to worry about it again but I'm glad I saw this response. I'm also building a street cruiser and mountain runner so I don't need full race suspension.
I know this goes back 2 years from when I did it, but i just went onto an online mazda parts supplier and ordered all new links with rubber bushings. Wasn’t as cheap as a set of poly bushings, but comfort never is.
i installed all the rears last year and have done a few track days on it. Very compliant with RB springs. I bought poly bushings for the front tension rods to go with the OEM lower control arms, I’ll tackle that sometime this summer.
I know this goes back 2 years from when I did it, but i just went onto an online mazda parts supplier and ordered all new links with rubber bushings. Wasn’t as cheap as a set of poly bushings, but comfort never is.
i installed all the rears last year and have done a few track days on it. Very compliant with RB springs. I bought poly bushings for the front tension rods to go with the OEM lower control arms, I’ll tackle that sometime this summer.
Do you have a link to the website you used? I am currently looking to get new bushings for all the suspension parts on the car, specifically the front is pretty shot on all the rubber.
This was for rear uppers (2) lowers (2) watts left, watts right, watts link, front LCA left and right. Edit, just spot checked website and some prices are a bit higher now.
Do you have a link to the website you used? I am currently looking to get new bushings for all the suspension parts on the car, specifically the front is pretty shot on all the rubber.
