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build diary << | show individual entries | >>February 27, 2005:
I spent some more time with the bump steer testing. Remember how I realised that my steering geometry was wrong some time ago? This forced me to move the tie rods below the steering arms, leading to the problems with the rod end limitations. Well, even with with my newly raised steering arms I still needed to either raise them further or drop the rack down. Maybe my measurements were done with the tie rods on the top of the arms after all. I suspect the truth is that I measured to the center of the arms. Regardless, I dropped the rack down about 1/4" (the limit without rebuilding the rack mount) and improved things fairly significantly. It's still not perfect but that will have to wait. The Seven goes back on the scales just to make sure. Since the change back to the stock intake manifold, the car has been very well behaved. Well, once I fixed that one bad connection in an injector wire. It feels quite healthy and the weather right now is perfect for tearing around. It's going to be a lot of fun at the track this weekend. A view from underneath.
The first foray on to the track was a little unnerving. The car didn't feel as planted as it should and never seemed to take a set. My girlfriend Janel (who supplied her Jeep as a tow vehicle again, poor girl) was along with me and started to get motion sickness after a few laps. The performance of the car shocked her. She'd been in it on the street where it is noisy, rattly and full of little zings and vibrations. Given her affinity for warmth and the recent weather, she hadn't been in the car for some time. On the track, the ferocity and violence of the car was overwhelming. Janel was able to help out with taking some tire temperatures, though. The rears looked pretty good but the fronts indicated a lack of front camber. That's the same thing I had decided after eyeballing them in the past. After a couple of tries this was dialed in and the handling of the car was transformed. The front of the car was utterly faithful to whatever you asked while the rear would move around wherever you wanted. Even in turn one - a high speed decreasing radius sweeper - the car was completely composed. I got a big silly grin. Other cars at the trackday included several Mazdaspeed turbo Miatas as well as a couple of aftermarket setups. The Seven was able to run away from many of them including a 2000 model with a 14 psi supercharger. The one that caught my attention was a brand new Elise, though. It was the first time the owner had taken the car to the track and he was only running about 7/10ths in the corners. I was only able to get behind him once unfortunately because he was taking people for rides and only doing a few laps at a time. One of the high points of the day was when I was driving Flyin' Miata's modified Mazdaspeed and I tucked in behind Bill Cardell driving the Seven. We had a great time playing around. I was obviously driving his car harder than he was driving mine but neither of us was hanging around. It's fun watching the Seven move around on the track. There's a surprising amount of body roll but it works well. Bill was impressed with the amount of leg strength needed for the brakes. With the new tires, it's basically impossible to lock up the wheels. I hadn't really noticed because I'm a wuss when it comes to braking. Maybe I'll put slightly different masters on. Mechanically, the car was almost perfect. The air filter fell off once and pulled a sensor wire off with it. That was fixed in a couple of minutes with no harm done. One of the fender stays started to crack and the fender assumed some odd angles. I've already reinforced one, this was the other. No big problem. Janel came out for a few more laps later in the day and had no more queasiness - either my driving was smoother or she was used to the car. She did notice the car was much faster. So, a fun weekend then. Oooo, we're not done yet. Sunday morning I was at an autocross back in Grand Junction. The Jeep was still loaded up. It's embarrassing showing up with a "trailer queen" to an autocross but hey, I'd spent the last day on the track and only been home for 9 hours! I haven't been on an autocross course in three years and it's quite a different matter running the Seven as opposed to my Miata. Even a light launch gave me a lot of wheelspin and it felt as if I'd been fired off a catapult. The runs were pretty frantic and I had a hard time getting ahead of the car instead of just reacting to it. What really impressed people was the slalom - the best part of my autocrossing has always been straight slaloms and the Seven just tore through it. It transitions cleanly due to the light weight and of course those exposed front wheels take all the guesswork out of placing the car. The Seven was mobile enough that I could dance it around fairly well. I had some good competition from a turbo Miata that was driven well and a WRX with enough power to get serious wheelspin despite four huge Hoosiers. I was worried about the Miata but my last run was fast enough to win fairly decisively. Phew - it would have been quite embarassing if I hadn't walked away with that one. A Seven is almost purpose-built for autocrossing. A good weekend. Some new videos have been added to the site. The new and improved trailer setup. I snuck another video on to the website yesterday - it shows the speed difference between the Seven and a stock Miata. Okay, this isn't a surprise. But it's still pretty fun to watch. Another photo of the car cornering. |