Has anyone installed this Rear Suspension bushing? Please post review. TIA.


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Madness Polyurethane Rear Suspension Bushings

 

Badass,

I've used these in other similar applications. All I can suggest, is be careful; study how this particular suspension component works. In my last application, these prevented some roll toe-in changes making the car very snappy at the back end. I installed hard rubber after and found these were much more comfortable, and, allowed this particular trailing arm to work correctly.

Bushing hardness should should also match suspension damping characterisitcs; hard bushing and soft damping, not a good combo...nor is the reverse.

 

I have them and they made a nice noticeable difference in all conditions I have experienced to this point. I have pss9's and they made the ride smoother and the suspension more "active" I am actually going to put them ( pss9's ) one click tighter on the street now.

Only downside is they raise the rear of the car slightly, the stock sponges :-) compress while the urethane ones don't. Since they are the same size, height and thickness and since the urethane ones don't compress the car sits slightly higher in the back than before I installed them. Since I have coil overs its no big deal to adjust them but I thought I would point that out. As soon as I get done playing with a couple things I am taking the car back to the scales and dial in ride height, corner balance and alignment

 

Thanks for the input. I have the koni coilovers on the car now w/ hsport comp bars and RDR camber links. I'll give them a try since the factory bushing seems like its too soft. If I get noticeable oversteer, I can go to full soft on the rear bar and maybe adjust the rear shock.

Any noticeable harshness in the ride w/ the bushing? What is the density of the bushing? Hoping that they will offer a fair amount of compliance and be about a medium firmness.

 

the ride is actually better, I have the rdr plates, h-sport rear arms upper and lower. I dont know the details of the bushings, sorry. They definitly help.

 

Part of thier design IS to remove some of the rear roll steer in the Mini. In this case, the more the Mini rolls, the more the stock bushings deflect causing understeer. This is either good or bad depending upon where you drive. Personally, I find this to be a valuable safety net on the road or track and completely undesirable in an autoXing event.

I would personally begin with the front control arm bushing - the rear most bushing. You'll still gain more control without removing some built-in safety margin.

Now you have two opinions.

 

I would rather have the springs doing the work, not the bushings. If you are spending a lot of money on coilovers, I believe the stock bushings should go. You have to adjust your suspension settings around these squishy bushings that probably won't stay the same for long. Webb Motorsports also carries the bushings.

Now three opinions.

Steve

 

All three opinions are certainly valid. The real struggle for me is answering this quesion, what does the durometer say? I removed all the stock bushings in another car and replaced all with poly from Energy Suspension. As it turned out, two were just too hard for the application - not a comfort observation - an operational one. Once I removed those two and installed hard rubber, the control I sought was there, the bushings worked as designed, although with much more precision, and, they were nearly as comfortable as stock.

This was a time consuming, but valuable, experiement.

 

All,

George of MiniMadness makes high quality products and has a good reputation with his successes in Tuner Challange and One Lap of America cars.

That said, I tried to do George one better and "let the springs, not the bushings" handle the rear suspension. Am using H&R sport springs and stock struts. I fabricated a set of monoball upper mounts, replacements for the bushings, for the rear struts, zero compliance. Big mistake. My MINI became an ugly beast on heavy braking at the track and on the street. The rear end hopped around violently and seriously upset the car's straight line stability. The monoballs were great for spirited street driving: pitching was materially reduced. I then replaced the upper monoball bushings with new stock bushings and the car is again much more predictable under heavy braking. Heavy braking was the only situation where I felt the handling suffered from the very stiff upper mounts.

The urethane bushings described in this thread are not the same as the monoball mounts that I fabricated. But, that experience of mine points to a potential problem when compliance is removed or severely reduced, at least in the rear end. If you do install the urethane bushings, test the suspension under heavy braking to make sure that all is well.

Regards,
John Petrich in Seattle

 

John,

Your experience exactly mirrors mine in other applications.

However, follow the thread about the front bushing for a while. I did not know that a dual compound bushing existed for the front control arm. If the same type of design exists for the rear I might try it. The bushing has to take on the properties of a rubber bush in my mind however; it must allow the suspension to work. Specifically, toe compliance at the rear end can create a very stabilizing or uncontrollable condition. I personally believe that rear toe affects stability more than the front. I'm leary of fussing with the rear bushing for the above reason. The toe and camber adjustment links are a different story.

Compliance affects the shape of the contact patch under differeing conditions, it is not always a bad thing. Instability is never a welcome trade-off ,in my mind. Your point is well taken.

Thanks.

 

I've had the Mini-Madness front control arm bushings and rear control-arm helper bushings on my `05 R53 for for a while now, and haven't found any negative effects. Both are somewhat firmer than stock, but no so much so as to take compliance out of the equation. Both make the car more precise and predictable.

I'm personally not an advocate of delrin or heim-joint bushing replacement for a road-driven car, both because it can make the car too unforgiving, and because the parts to which they are attached are not designed for severe road shock to be transmitted - they need a bit of cushion from vibration to avoid long-term fatigue.

Today I installed the M-M Rear Suspension bushings. These replace the soft foam-rubber bushings at the top of the rear shocks. The OEM are soft: you can easily dent them 3-4mm with a thumbnail. The replacements are solid urethane, a bit softer than the heel of a shoe. You can dent them maybe 1-2mm with the same thumbnail.

I found that, like the rear trailing arm bushings, the effect is simply to take some slop out of the rear suspension, without any apparent negative side-effects during hard cornering. The tail end of the car is simply that much more predictable. Compared with the trailing arm bushings, these don't seem to have quite as much of an effect, but what they do is in the right direction.

The stock bushings are intended for use with the unpleasant OEM shocks, which need a bit of help to reduce noise and harshness. With my Koni FSDs, that might not be needed, and letting the shocks do their job results in better predictability and control when you are at the point where the tail is starting to get loose.

However, even with the FSDs, I found a noticeable increase in plastic-rattle noise on my local poorly-maintained roads. I'm taking them back out in favor of the stock bushings, as noise-reduction is a high priority for me.

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