Test n Tune - 04/13/14
Finally, after three years we got around to a real Test n Tune in the Jeep. We made a trip down to LA... or lower Alabama on Sunday, to visit the SCCA Wiregrass Region and enjoy the wonderful concrete surface that they have to run on.
Why concrete you ask? The most important event of the year is the SCCA Solo National Championship that's held in Lincoln Nebraska the first week of September. More than 1000 competitors gather to battle for the ultimate autocross win, and it just so happens that the event is held at an old Air Force base on a concrete airfield, located at Lincoln Airport. It's an old Strategic Air Command base, and the 12,901 foot primary runway was designated as an emergency landing site for the Space Shuttle. But we get one big area (big enough for 2 courses, a practice course, two grids, paddock space for 1000+ cars, trailers, motor homes, and other assorted vehicles, tents, and people. Great site.
So concrete testing and seat time are very important if you expect to do well at the Nationals. Unfortunately, there aren't any sites in the Atlanta area so we end up having to drive quite a distance to find one. This autocross was held at Hunt Army Stage Field located just outside of Dothan Alabama. The field is used for helicopter training normally, but when it's not in use, the Wiregrass Region holds their autocrosses there.
It was a perfect day for an autocross with a nice breeze, sunny skies, and temps in the upper 70's to low 80's. The concrete surface is like most airbases and is a coarse but smooth surface. No loose stones, gravel, or grit that I could tell.
We brought a whole crew with us this time. Myself, Jim Murphy (the car owner), Dan McMahan, the suspension tuning and tweaking guy and the Jeeps mechanic, and my son Matthew and his girlfriend Calley. Matthew and I were doing all the driving, so the plan was to split Jim's runs between us. We knew they got a lot of runs there since the turn-out is usually pretty low and we were right. We were split into three run groups so the car pretty much ran all day long. Dan made changes to the track bar on Matthews first 4 runs, and the front sway bar on my first 4. By the time we were about halfway done, Matthew and I had both agreed on what we felt like was the right balance. Matthew made the statement that it didn't feel like the front of the car would plant and turn like it should. Dan made a few more adjustments to the alignment and it got better.
But things REALLY changed once we took off the Avons and put on the Goodyears that we ran at the Nationals. Night and day difference. The difference was so profound, the car was picking up the front tires under hard acceleration. Matthew got two runs on those tires and I started a run... and it was then that things went bad. I was about a quater of the way through a run when I heard a loud bang and the car started wobbling around. To me, it felt like a tire had come off, but instead, the front arm on the left side of the axle had snapped in half, so the axle was cock-eyed in relation to the chassis. In the process, the rod punctured the fuel cell when it snapped.
The broken link is sticking straight up in this picture. It would normally be pointing to the right and be horizontal. The tube was very thin walled and obviously not up to the task it was installed to do. Heavy duty rods are going back in.
So that ended the day. Matthew ended up with 12 runs, I had 10, Extremely valuable testing and seat time. I learned quite a bit about the car (even though this is the 3rd year I've driven it!) that will certainly help out in the future. Next comes 4.56 gears (instead of 4.11) and some changes to the inter-cooler piping to help out on throttle lag.
Keep in mind that Jim Murphy's results were actually mine and Matthews
Raw - PAX - Class
One of my runs...
One of Matthew 's runs...
4/21/2014 12:00:15 pm
By the end of the day, it felt great and I felt much better about my driving. VERY productive day.
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Just some thoughts about driving the "Jeep", a SCCA (Sports Car Club of America) E Modified car that remotely looks like a Jeep. The Jeep is owned by Jim Murphy, so I just show up and drive it!