Tuesday, May 29, 2012

Faster, but Frustrating

The good news is it didn't rain. A few days before the 4/21 event, it looked like a soaker, but instead it was a truly nice day, with temps in the low 70's, just a few degrees below ideal for my car. My times were some of my best ever, and I set a record for "PAX SS". I out paxed a lot of people that usually beat me, and my season pax standings score was 92.5, which is also a new high. The other good news is Matt Neiman was at this race, and racing well. This time I had real solid competition.

Matt's car is a turbo, stroked, Miata that is prepared almost entirely to the class limit. Matt is also considered an instructor driver for the Renegade Miata club. I was quite surprised that I was beating him last year, and to hear him tell it his suspension settings were giving him issues all year. This year he seems to have sorted them out.

The bad news is he beat me by 0.309 seconds. The other bad news is I had cone troubles again. This time it was particularly frustrating because I had no idea where I was hitting the cone. It turns out I was just barely basing the same cone. In other words, I was running over the base, but not actually hitting the cone, which means it wasn't actually making a noise that I could hear, and therefore I had no idea what to do differently. 

The result was that on runs 3, and 5, I ran a time that should have been a significant improvement (we won't talk about the 6 cone debacle that was run 4). Repeatedly, the time slip I was handed looked good, and I started to celebrate only to hear later that I had actually hit a cone and I was in danger of coming in last. Finally I played a hunch and took a calculated risk on run 6, and peeked in my rear-mirror, knowing that I probably would loose time by doing so, and I managed to spy the offending cone.

The next run I hit a different cone, but I am sure I missed the one that had been plaguing me. On the 8th and final run I managed to repeat my last run heroics, and run my fastest time, clean. I found out from my co-driver David later, that I wiggled a cone, but wiggle is good, and based is bad! The difference is probably less than half an inch.

This is better than last year where I had a string of last runs that had an awesome time, but a cone penalty as well. However as PJ put it... I need to drive that fast on my first run. All I could say in response was: "Yes I do!"

Thursday, April 19, 2012

New Look

Changed the background, tweaked some colors to work with it. I also improved the standings page with photos of almost all the competitors (courtesy of Eddie Savage of course).

Saturday, April 7, 2012

A Good Start

Last year at the start of the season, I was lamenting not being able to attend the 1st event and 4rd place finish in the second event. Last year there were also only 4 competitors total in the first 2 races. It was a smallish class and a seriously uninspiring start.

This year, is nearly the polar opposite. I made it to the first points event, and Super Street Modified was the largest class of the day with 9 total drivers. Also, this year I found a co-driver and as for who seems to be a cool guy, committed to racing and excited to drive a Lotus.

As for how I did... this more or less sums it up:

Thursday, March 29, 2012

Yes We Camber!

Now that I have a fresh new U-joint in the steering and the winter gas is all burned off, it's time to get ready for racing. This year I intend to work hard to ensure that the camber and toe are properly set, the car is corner balanced, and I hope to work out the best settings for my shocks, sway bar and tire pressures in light of the new setup.

That's about a six variable optimization (if you don't count weather & temperature), which is kind of daunting. Where does one start?

While I was doing the work on the steering, I noticed that my right side had a lot fewer camber plates than the left, so I had a strong suspicion that my side to side camber was not correct. Therefore, since this appears likely to be out of whack and since the settings are available on Lotus-Talk, I'll start there.

Over the winter, I bought a SmartCamber tool, but before I can use it I need to get the car on a level surface and equipped as if it were racing. We want to optimize for racing so the setup will be slightly off for road use, but road driving isn't a competition (despite what the folks in the urban assault vehicles seem to think).

I put on the race tires, removed the tow bar and put 150lbs of books and break rotors in the driver's seat to simulate the driver (which is around 7% of the weight of the car!). To level the car, I shimmed the wheels with linoleum tiles (available for 69 cents each in Home Depot). I measured how many each wheel needed with a 78" long level resting on a couple of sockets and the SmartCamber tool, which is really just a fancy level. After marking the point I measured the tiles, rolled the car to that point and jacked it up. After jacking the car up, and placing the tiles under the wheels I also inserted a plastic bag folded over with some motor oil between the folds. This allows the tires to slip sideways when the car comes back down and avoids the need to roll the car back and forth.

The camber measured -1.1 on the right side and -0.1 on the left side. That's a whole degree of difference, which may go a long way to explaining why my car tended to ABS earlier than it should in threshold breaking. Also, thinking back I can't remember any spins that were clockwise. I hadn't thought about it before, but I suspect that the setup I had settled on in terms of shocks/tire pressures and sway bar settings last year was flawed. Possibly, the right side of the car was slightly tail happy, but neutral on the left, which would be consistent with a better camber setting on the right that gave the front right more traction in a left turn than the front left had in a right turn.

The rear was better, -2.0 on the right, and -1.7 on the left. The latter is stock and the former is just a little bit less than the recommended setting for autocross which is -2.25.

I took out all three shims on the front left, one on the right rear and two out of the left rear. The result was -1.0/-1.1 in the front and -2.1 -2.3 in the rear. This is now within the .2 side to side tolerance recommended by Lotus (just barely for the rear). Many serious racers seek even more negative camber in the front, but to achieve more one needs to replace or mill the steering arms.

Anway, Next up... Measuring the Toe. Here are some pictures of my setup...