...I also experienced an issue with my Energy Suspension bushings that's worth mentioning. When I first installed them, I forgot to order zerk fittings and grease, and since I was limited on time, I just used the grease that came with the bushings. I put ~540 miles on them including ~45 min of track use, and I took them back off to install zerk fittings. The rear bushings looked brand-new, but when I removed the front bushings, they basically crumbled into pieces.
Here are some pictures of the carnage:
I noticed some minor squeaking over rumble strips, but otherwise, they were silent, and there was little resistance when I moved the control arm. I was very surprised to see this kind of damage with such little use.
I called Energy Suspension and emailed them a lot of pictures, and their engineering team said it was caused by a manufacturing defect that shouldn't happen again. Interestingly, they also recommended AGAINST installing zerk fittings because drilling/cutting the bushing could cause tearing when it's stressed. I installed zerk fittings anyway. I've put another ~1500 miles including ~3 hours of track time since then, and I haven't noticed any issues, so hopefully they're fine now. I haven't pulled the control arms off again, but there is no compliance when I tug on the wheels. Hopefully nobody else has this problem.
Great pics, and yea... that looks like a bushing that was made wrong. Energy Suspensions isn't the worlds best brand, but they do make a lot of offerings and generally speaking they work well. That seems like a bit of a fluke - sorry you experienced that. We sell Energy... and Powerflex... and Whiteline... and other brands of polyurethane / non-rubber elastomer bushings and I feel they ARE appropriate for many dual purpose and even purpose built track and autocross cars. Let me make my case....
The Energy Kit for the S197 front LCA is pretty basic. The rearmost bushings are the MOST important ones to replace. Many times we leave the front bushings alone, but if they are made right, installed right, and greased they should last a decade or more. I'm not saying that "ddd4114" did anything wrong here - those do look like they weren't made correctly. Greasing those wouldn't have likely made a difference, but long term use without grease zerks can and will kill a poly bushing.
We show picture this in our instructions for the S197 Energy Bushings but not everyone reads them - the knurled finish on the LCA part that inserts into the bushings needs to be sanded smooth, otherwise it will chew up the poly bushings as shown above. This is present on the stock control arms for the rearmost front LCA bushing.
Adding a grease zerk to ANY poly bushing is muey importante! I cannot overstress this point.
There is never a polyurethane bushing we install at my shop that does NOT get a grease zerk. I just don't give the customer the option to "opt out"....
Corvette, Miata, Mustang - don't care. If it is a bushing that pivots (in ONE axis) and is made of "not rubber", it gets a grease zerk or it doesn't get installed. We've seen non-greased poly bushings last less than ONE YEAR... so its just become policy here. ZERK THEM ALL. #PolyLivesMatter
If the class rules, customer's budget, and the car's intended use all allow for a metal spherical bushing, then sure... that's a better way to go. But NOT all bushing locations or race car builds NEED metal or even Delrin bushings. These will wear faster, make more noise, and add suspension "slop" when worn. We never used these on pivoting control arm bushings for street cars unless it has some sort of weather tight enclosure. Those do exist... some BMW rear suspension bushings are spherical from the factory, BTW. But they are VERY well protected from rain and dirt.
Likewise, Polyurethane material has its limitations. It is NEVER appropriate to use a solid poly bushing in a "dual axis of rotation" suspension joint. The BMW E46 LCA shown above uses a 2-piece, 2 durometer poly bushing to combat this. The hole for grease to travel is drilled through the housing and the outer poly bushing. This way grease can travel all the way to the inner pivot point - where the two poly pieces meet.
Regarding performance, I also have noticed little benefit (after adding poly LCA bushings). At the same time, I've noticed little detriment to ride quality. My lap times aren't any better, and the response of the car hasn't changed. Despite the durability problems of the OEM bushings, I'm almost tempted to suggest replacing the OEM control arms (at ~$140/ea.) instead of spending the money and time on installing poly bushings. I'll have to keep an eye on mine over time to see how well they hold up.
With all due respect, scientific track testing is slightly different than seat of the pants testing or even just a causal look at lap times. But there is an easy test you can do with an S197 Mustang to SEE what the nasty fluid filled LCA bushings can do...
With a stock S197 with the massive rubber/fluid filled front LCA bushing installed, do this.... have a buddy drive the car while you stand nearby. Have them accelerate to about 20 mph than stomp on the brakes. It helps if you stand where the car will come to rest. WATCH the wheel squirm fore-aft (wheelbase change) and in/out (toe change) as it comes to a stop. It doesn't take much braking effort or speed to SEE this happen. I've done this with lots of folks and its pretty eye opening (I need to make a video). That toe change only gets worse as brake pad friction and mechanical tire grip goes up. It changes the turn in feel, tire wear, braking stability and more. I've driven so many of these cars with and without poly bushings I can always tell the difference just by driving them hard.... I can feel the wheel flopping around with the stock rubber bits.
Poly bushings remove that flex and slop that the OEM rubber bushings have - the rearmost bushing on the front control arm makes the biggest difference here. Its the size of a beer can and filled with goo. "Goo" is not a good suspension material.
Of course when we load these cars laterally in a corner (again, this is amplified on better compound & wider tires / firmer spring rates) the stock fluid filled ding-dong LCA bushings will DEFLECT so much that you will lose "dynamic" camber. Between the giant rubber strut top mount and the big rubber front LCA bushing you could lose 2 degrees of camber or more in a corner. That will show up over time as adverse tire wear at the shoulder, less lateral grip, etc.
This is where high quality pictures taken at an autocross or track day come in very handy - and why we take and post so many pictures at events like these. We can then look at the car loaded up in a corner and SEE things that you might not feel from behind the wheel. This guy above probably things he's hauling the mail, but in fact he's losing so much camber that the outside front tire is losing much of its available grip and shredding the outer shoulder. Poly bushings added to this car can usually be class legal for all but the stockest of classes, won't break the bank, can ride well and last a long time - if properly installed and greased.
Rubber suspension bushings can become or are often intended to be bonded to the control arm points or swaybar, and that often adds unwanted suspension bind. These rubber bushing points then have to pivot against themselves to rotate. To do that enough means they have to be soft. We often see OEM swaybar bushings that are rubber but "bound up" so badly we cannot rotate the swaybar in the chassis mounts with the endlinks removed. That is BAD and one thing we aim to fix with aftermarket bushings - be they poly, Delrin, or spherical.
Any pivot point in any suspension should move smoothly and with almost no effort with the springs removed. We will do this on cars and use the "pinkie finger" test.... if it takes more than a pinkie finger's effort to rotate a control arm or swaybar with the endlink, spring and/or strut damping removed, there's unwanted bind in the system. That bind is something a damper can't control, and makes for a funky driving feel in a highly tuned setup.
So that's why I feel poly has its place in HPDE, autocross and Motorsports - it has it's place and it's limitations. When used correctly poly bushings can remove slop and bind from your car's suspension, and reduce camber loss and toe change. While ddd4114 had some bad luck, and that's unfortunate, but it is very much not the norm. We've used poly bushings in hundreds of cars with excellent luck, as long as they get installed and greased regularly (1-2 times per year).
So anyway, that's my 2 cents on poly bushings.
Cheers,
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