Archives

CDC Autocross Event 5, 5.29.09

sandy

Since the BMW is still on jack-stands in the garage, I decided to take out the MINI for the Capital Driving Club autocross at Bowie Stadium this weekend. It was sunny and hot, but fortunately, not yet so humid. I was competitive with the other MINIs that were running, but I wasn’t up there with the top 15 this time. No grip on the dusty course (at least that’s my story and I’m sticking to it…)

behind

You can see from the photos above that the course was quite dusty. It started with a clockwise half-loop into half a figure-eight and another half-loop into a short slalom. Across the top of the parking lot through as series of tightly spaced off-set gates with a quick right-left-right-left, followed by a loop to the finish. You sort of get a feel for it from the video, but the camera mount is too low to see the cones. I’ll have to figure out another way to mount the camera in the future.

Thanks to the CDC group photo pool for the photos of my car. I also posted a bunch of photos from heats 1 and 3 to the pool as well.

Well, there’s your problem…

rack

I’m pretty sure that there steering rack belongs somewhere under the car…

Day 1 of the steering rack adventure is complete. Without making too much of a mess, I managed to get all of the hoses off, fluid drained, and the old rack removed. The tie-rod links proved to be a pain, but after much wrangling, the whole thing finally came out.

If installation is the reverse of removal, do I have to bust my knuckles and pinch my fingers in the same places as I put it back together?

Stealth Not Ready for Prime Time

I was hoping I’d be able to make it to the May NCC HPDE at Summit Point at the end of the month without having to replace my steering rack, but no luck. The boots are full of fluid. There’s also a vibration in the drive-line which probably indicates the U-joints are shot.

Of course, this model doesn’t have replaceable U-joints so you have to replace the whole drive-shaft. The good news (as such) is that a replacement isn’t that expensive, and a good, re-manufactured and balanced shaft is only about $400. Of course, you have to drop the entire exhaust from the header back to get to it…

Since there’s no way it will be repaired before next weekend, I thought I catch up on some of the details I skipped when I rushed on to the track in March.

Caliper Before

I’ve always really hated how the stock rotors and calipers just rust away. If you’re running the old bottle-cap wheels, you never see it, but with the open track wheels it really looks poor. Hopefully the extra coating won’t add to the heat build-up.

Caliper after

And no, I didn’t forget the retention spring. I’m just letting the paint dry before putting it back on.

518hp MINI

MINI Dyno Chart

I recently lost my cell phone which turned into an opportunity to get an iPhone. There are a couple of interesting automotive apps available for iPhone so I thought I’d test a couple of them.

The image above shows the Dyno results for the MINI using an app called Dynolicious. It shows a 12.82 second quarter-mile at 137.4 MPH and a peak horsepower of 518 HP. In third gear. On a public street…. OK, so maybe the calibration was off a bit. My second run after calibration showed 229 HP, but I didn’t capture the image. I think that’s still about 10% too high, but more realistic given the previous Dyno results at 197 HP.

BMW Dyno sheet

The second image shows the results for the BMW — Even though it still says MINI — which I suspect are more accurate. I’m really most interested in initial acceleration so the chart really tapers off as soon as I get into third gear. I was trying to compare the BMW to the MINI to see which is quicker off the line for autocross. I decided to try a second app as well called PocketDyno+ which I thought was a bit easier to use and set-up than Dynolicious, but doesn’t produce the really cool charts you see above. The results were interesting.

The MINI has about 25% more HP than the BMW; weighs about 200 lbs less, and is almost half a second faster covering 1/8 mi; but in the first 60 ft — which is what really counts in autocross — the BMW is faster by .15 seconds. Both cars are running the same Falken ZE 912 tires and the test was conducted on the same stretch of road under the same conditions. I suspect the effect of the weight transfer on the FWD MINI negates the superior power and torque available until the cars starts moving, and then it plays less of a role in straight-line acceleration.

CDC Autocross Event Four, 5.9.09

3Wheelin

On Saturday I finally made it to a CDC autocross event. This one was held at the Triple Skid Pad at Summit Point — same place as the BMW Club event, only this one wasn’t a sogfest. BSR has finally paved the aprons around the inside of each skid pad and cut-out, but the infield is still very soggy. The course was fairly simple, but because of the lack of grip, was actually quite challenging. I wasn’t sure if it was going to be wet so I took both the RA1s and the Hankook slicks. I ran the morning runs with the RA1s and then the slicks in the afternoon. Right off the bat, the slicks were 3 seconds faster and ended up being almost 5 seconds faster.

GeorgeCo

The video is from the last run. I still haven’t fixed the audio, so you want to turn down the volume.

The results aren’t posted yet, but I suspect the winner was in the low 47 second range. I’m hoping for a top ten finish. My best was in the high 48s. As a comparison, my best on the RA1s was in the low 53s. I probably should have heat-cycled the Hankooks before running them last month at the first SCCA event. They really had much more grip this time, even on the slick surface. I think they are going to work out well this year and seem to be wearing fairly evenly so far.

Triple Skid Pad

The only down side was the poor fellow driver in the Lotus Elise who went off into the mud only to turn up a 30-pound rock with his front splitter. With a large “whack”, bits of carbon-fiber were flying everywhere. I’ve been told the only way to make repairs is to buy a new clam shell for the front half of the car. That’s an expensive weekend.