We’ve been hearing a squeaking over bumps coming from our UMI lower rear control arms. Not knowing the exact age of the bushings on the chassis side, we knew a replacement was in order. Researching on UMI’s website, we easily found replacement bushings for our control arms. Ordering and checkout was easy, and our parts arrived neatly packed just a few days later. UMI also included a TON of stickers, which we always appreciate.
Removal of the control arms is an easy affair. We jacked up the body, supported it with jack stands, and let the axle hang free. Wheel/Tire removal was next. Then, working one side at a time, we unbolted the chassis and axle bolts, and pulled the control arm out of the car. Then, using an appropriately-sized socket, we hammered the inner metal sleeve out of the bushing. With this sleeve free, we started one of the bushings by prying on the edge of the pushing with a wide flat-bladed screwdriver, then resorting to pulling with our hands to remove the half bushing. With one half out, the other was easily pushed out by hand.
Installation, as they always say, is reverse of removal, just with a lot more elbow (and bushing) grease. Using the supplied Energy Suspension grease, we lubed all sides of the bushings, and the outside diameter of the inner sleeve. Then we installed a bushing half, pushed in the inner sleeve, then installed the other half. the bushings tend to want to walk out of the control arm on their own, so a quick installation into the chassis-side mount is key. We elected to bolt the axle-side on first, then lever the chassis side into place using the weight of the axle. We then slid the bolt home, and went to hand-tight. After replacing the opposite side, we set the car back on the ground and tightened the bolts to spec.
This past weekend we attended the last championship event of the season for the San Diego Region at the classic Qualcomm Stadium. This event was on the west lot, which typically results in bigger and faster courses. This course, designed by Arvind Govindaraj, was no exception. We entered the Stealth Bomber in CAM-C, running our street wheels and tires, Nankang Noble Sport NS-20 275/35/18 on Avid.1 AV-06 wheels in 18×9.5 sizing. These tires are a 360tw all-season, so we knew we wouldn’t have a lot of grip to work with. We did elect as usual to adjust camber in to -3 degrees from our street setting of -1 degree, which brings with it a slight bit of toe out. This removed a bit of understeer and gives the car excellent turnaround. Since this was the last event of the year, and our late start in the season already removing us from the points race, we elected to enter in X-runs to allow for ride-alongs.
The first run was fast, despite not seeing the course until we ran it, but we were presented with a very disappointing 79.83 time. Turns out the car in front of us had spun off course and stalled, out of our line of sight. That meant a rerun, and that our first time was actually the stalled car’s time. Great! The grid was packed, and we did have a bit of traffic and wait time before getting to our second run. We came in with a 59.108+1, clipping the first cone in the second slalom. Faster than the rest of the CAM-C field, but we knew there was room on the table. Our final run ended up being our fastest at 56.302. The next fastest CAM-C car put down a final time of 60.250. Nearly a 4 second lead on street tires, we were ecstatic! The training received during the SCCA Novice School in November, along with the new parts and adjustments, had made a world of difference. 2016 is going to be a fast and competitive season.