Project Car Diaries: Here’s How Just $120 in Chassis Upgrades Revitalizes Your Car
Replacing and reinforcing bushings is still one of the best and most noticeable improvements you can make to your car.
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In terms of dollars-per-noticeable-improvement, it’s hard to beat replacing bushings as a best-value upgrade on an older car. We often forget that something as simple as replacing some old rubber can make a huge difference in the way a car rides, feels, and responds. By that same token, improving upon some automakers' stock bushing designs can right a lot of wrongs for short money as well.
Recently, I replaced my 2011 BMW 128i's sway bar end links and bushings and reinforced its rear subframe bushings. All in, it was less than two hours of my life and less than $120 worth of parts incredibly well-spent. Why can't more jobs go this smoothly for so cheap?
This quick job of replacing the sway bar endlinks and bushings while also reinforcing the rear subframe bushings was done to tighten up some looseness and improve all-around response.
Tools and Supplies
On the Front-End
In the ten-ish-thousand miles I've owned my little BMW coupe, I've seemed to always overlook sway bar endlinks and bushings. Even when I swapped its front dampers for quality Koni Sports (aka “Koni Yellows”), paid extra-close attention to its setup for track duty, and focused on its braking and grip performance.
But one day it randomly dawned on me: I should closely examine those and replace them. In fact, I didn't even bother with the first bit, I just ordered endlinks and bushings from FCP Euro for a very reasonable fifty-or-so bucks before tax and shipping. I was right in my jumping to conclusions: The endlinks' rubber bits had become too flexy, and the bushings were completely cashed.
With little more to do than secure the Bimmer's front end on jack stands, remove its wheels, and go to town with a ratchet, I had everything swapped in half an hour, followed by putting each corner under load for final torquing. A quick test drive revealed immediate effects: the car no longer clunked going down my driveway, and the front end felt more solid and well-damped rolling down the road. It's amazing what fresh rubber can do, no matter how small it is or where it lives on the car.
Towards the Back
The next job made me feel especially guilty—why on Earth did I not accomplish this earlier during my year-or-so ownership thus far? Especially considering the fact that my buddy who sold the car to me included them with the sale: Whiteline's polyurethane subframe bushing insert kit.
These inserts fix a common problem on E9X and E8X BMWs: the subframe bushings have a lot of flex from the factory, which causes excessive lateral movement and drivetrain slop. The deflection that occurs disallows the shocks and springs from doing their jobs, effectively, and exasperates understeer on track. Additionally, since the rear subframe contains the differential, this sloppiness creates an inefficient route for power as it's headed towards the rear wheels. Finally, the latter inhibits smooth shifting, too.
There are other options out there, such as metal inserts from 034 Motorsports and full-on bushing replacements, but the 1 Series community had nothing but positive things to say about these, so how could I say no for free-ninety-nine?
Installation is a little more detailed than the former job above, but not by much. The key is using a lift, so I rented space at Your Dream Garage nearby in Southern California and went to work.
I hoisted the 1er up to a comfortable height, removed the wheels, then brought it up a tad further to fit myself and a jack underneath to support the subframe. Next, I got all four subframe bolts ever-so-slightly loose before undoing just the rears. Then, I lowered the jack ever-so-slowly, keeping an eye on nearby brake lines and wires to avoid pulling on them. Once I had just enough space, I lightly greased up each insert and placed it in its home.
Up next, I brought the subframe back up enough to get two new bolts in snug (but not torqued) and moved on to the fronts. These required removing some trim and chassis bracing, but that was all of a few extra minutes. I moved the jack to the rear diff, removed the fronts' bolts, and again lowered the subframe down just enough to install two greased-up inserts. Once they were in, I got everything back into place, put some pre-load on the subframe, and torqued all bolts to spec.
The Juice Was Well-Worth the Light Squeeze
The end result was immediately noticeable and immensely impressive. The car rolled along more solidly, felt quicker to take off, and shifts were even smoother—not that I ever had any real complaints about how this thing's sweet six-speed shifted before.
There was a mild increase in noise, vibration, and harshness on the highway, but nothing that'd get annoying over time. In fact, after driving over 900 miles on a recent road trip, it wasn't an issue at all. I can now feel more of what's going on at the rear end, which is a welcome change that will bode so well for on-track driving. Hopefully, peoples' comments about these simple contraptions helping extinguish understeer are very real as well: I can't wait to find out.
Don't Wait—Replace Your Bushings
If you're thinking about doing any kind of chassis-slash-suspension work, make sure to take on all associated bushings in the process. Granted, I dug how the car handled pre-bushing replacement, but now it's even better. What a solid—pun intended—upgrade for such little time and money. In my BMW 128i's case, it'll accompany a future steering upgrade quite well, to boot.
Click here to come on more wrenching adventures with us in Project Car Diaries. We work on Euro cars, Japanese tuners, American muscle, and more with new installments every week.