Things that go Whump in the Night
I am always amazed by the chain of events that leads to discovery. This past weekend, I was getting my MINI ready for winter. We don’t get a lot of snow here in Maryland, but when you car is only a few inches off of the ground, it doesn’t take much to slow you down. I figured the splitter would act like a dive plane in the snow. With that in mind, I decided to take off the splitter, close the brake duct holes, reinstall the fog lights, and trim a inch off of the bottom of airdam to gain some more clearance.
I had the car up on jack stands with the front wheels off. I remember looking down into the center bore of the camber plate (photo above) on the driver’s side, thinking it didn’t look quite right. I compared it to the other side and noticed the gap was about twice as large. I figured there must be some movement in the receiver, and since I had been working on the hub, maybe the downward pressure had made it droop. Then, as I reinstalled the wheel, and was pushing down to tighten the lugs, I heard a “whump”. The bearing had dropped out of the receiver. Even I know enough about suspensions to think, “not good….”
Sure enough, the urethane bushing had failed. The bearing was still attached to the top of the strut, but the strut was no longer attached to the receiver. From the machining that appears to have taken place, it looks like it has been loose for a while.
I talked to the manufacturer and they are going to replace the camber plates. That’s good news, and the car is still drivable, but I have to be careful to avoid large potholes. Once I line up the bearing, and lower the car to the ground, the weight of the car along with the compression of the spring keeps it seated, even when I jack the car up again. I can make it fail, but I have to put a lot of pressure on the hub to drop it out again.
So this presents an opportunity: If I’m going to have to have someone reassemble the struts, I might as well replace the shocks. (Quiet: Rationalization in progress.) I’m not yet good enough to really take advantage of coil-overs. Plus at $1200-$2500 I can’t afford them anyway. I’m thinking about 3 options:
- Koni Sport. The yellow Konis are adjustable. The fronts can be easily changed through the center bore of the camber plate. The rears are a little harder to use since you have to remove the shock to adjust them. I’ve heard good things from people who set the rears to the mid setting, then adjust the fronts to suit conditions. Soft for daily driving or in the rain. Hard for autocross/track. Designed to work with lowering springs.
- Koni FSD. FSD stands for frequency selective damping. That’s a fancy way of saying that the have a softer rebound rate for a quick (high frequency) compression such as seams on the highway or a pothole; and a hard rebound rate for slow (low frequency) compression such as on a smooth track. Sort of a cake/eating thing. They are not adjustable, but they compensate for the two primary goals of the daily driver/occasional racer.
- MINI JCW. The JCW suspension is designed to work with shorter springs which should help with the harshness of using stock struts on lowering springs. They aren’t adjustable and they don’t offer two distinct damping rates, but they’re OEM.
I’m leaning toward the Koni Adjustables. If I can dial out the harshness of my current suspension, then maybe people won’t worry about their fillings when they ride with me. The ability to make adjustments gives me something else to play with (or blame) next season. That’s a bonus.
Catching up with Fall Track Days & Progress on the BMW Stealth Project
I haven’t been keeping up with blogging so I’ll try to catch up with a few things in this post. With the economy in a tailspin here in the US, I’ve put my BMW project on hold for a while. There are a couple of advantages to this strategy: It preserves cash should we have to throw everything in the Volvo and head to Mexico; and if I wait until January, then the BMW will qualify as “historic” according to the great State of Maryland and I can skip the Maryland State Inspection (and associated fees).
Since I’m not making any progress mechanically, I thought it would be a good time to even out the flat black paint scheme. Here you see it before the attack of the black spray bombs.
And here it is afterward. You can see how far I’ve gotten by looking at where the door meets the rear quarter-panel. From that point back to include the roof remains to be painted. My goal is a uniform satin finish. Sort of Stealthy.
Back in October, I went to the Fall Driver’s School at the Shenandoah Circuit, Summit Point, WV.
It was a great three days of track time, but at the end of the first day, my friend hit the wall at the start of the main straight.
He and his passenger were both unhurt, but his 2005 Corvette was totaled. I was actually quite surprised how well the passenger compartment held up. He dropped a wheel off the outside of the turn going 85+ MPH and skidded across the track hitting the opposite wall with the car rotated about 110 degrees. Both airbags deployed as the car ricocheted off the wall. Now you know why I’m working on a dedicated track car.
SCCA Autocross Event #7, 9.28.08
Today was the final SCCA event of the year at FEDEX Field for the Washington DC Region. The course was long — almost double the usual length. With some tricky off-camber turns and off-set slaloms, it was too long to try to memorize so you tried to pick out the tricky parts and ride out the rest. The day was rainy off and on. We made it through three runs in the dry before the final run in the wet. Thinking it was going to be wet all day, I decided to run the Azenis instead of my V710s. It was probably a good choice for a drying course. I also recently switched to Hawk HP plus brake pads which really had much more grip than my old tired EBC pads.
WDCR SCCA Autocross Event #6, 8.30.08
I haven’t managed to make any of the local SCCA autocross events so far this year. I bought a season pass last winter, but as it turns out, I had to work during the first five events. I enjoy the longer courses the SCCA runs, but don’t enjoy the events as much — everyone is so much more serious than at the BMW or CDC events. Nonetheless, the SCCA events are a good way to measure your progress. At least some people in SM still don’t take it too seriously.
Today’s event was in the A lot at FEDEX Field outside of Washington DC. The course was very fast, with a couple of seriously off-camber corners that caught out many of the high horse-power cars in AS. There was also a slalom that you cold enter from either the right or the left. To enter on the left, you had to modulate your speed in the corner leading to it. This proved more challenging for the rear wheel-drive cars than the MINI. If you entered on the left, you exited at a better position for the turn following the slalom.
I scored mid-pack for Street Mod which is much improved over last year where I was in the bottom 10 percent. I found some more pictures posted on SMUG.
Ah, There’s Your Problem
Well, there’s your problem. Your engine isn’t attached to your car.
I was going to start working on the drive-line today. I know the flex-disk is shot so I got a new one along with the center bearing for the drive-shaft. As long as the drive-shaft is out, I was going to replace the bushings for the shift linkage since it’s easier to get to when the drive-shaft is out.
As I was sitting in the driveway about to pull into the garage, I was thinking there was an awful lot of vibration from the engine. Maybe what I was feeling wasn’t all coming from the drive-line. The engine idles fairly smoothly (for a car with 214K miles) so if there was vibration in neutral, the source had to be something other than the drive-line.
Sure enough, both motor mounts were sheared and the engine was sitting about an inch to the left of center. It was easy enough to get the broken mounts out, but moving the engine back to center to lower on to the new mounts was a bear. I finally managed to get it to swing around and lower back down. Now that the engine is back in the right place, I have to see what else doesn’t line up anymore. Luckily I had some spare mounts in the garage, but that wasn’t how I had planned to spend my day.
8/29/08: Update. I decided to check the transmission mounts today. One was still attached. It’s amazing (or scary) how much more smoothly the engine idles when it’s actually attached to the car.
