Sunday, April 24, 2011

(137) Engineering pixels

Today I'm going to do a good session on the simulator. My task? Engineer a setup for Mazda Raceway Laguna Seca on the simulation driving the Ford Mustang FR500S. has a very accurate recreation of Mazda Raceway and I know the track fairly well, so I decided to see if I could get myself some fast laps and improve the car mechanically.

The Mustang is a good choice for this exercise, I think. It has odd suspension design, it's heavy, and has temperamental handling.

 The Mustang FR500S.

I'm starting with the factory base-line setup for the car. This includes an already fairly aggressive stance on the car, with higher rear ride height, a decent amount of camber, low tire pressures and toe-in/toe-out already set on the car. These more aggressively tuned settings are offset somewhat by the lack of a rear anti-roll bar, slightly higher front tire pressures and soft damper settings. These settings should make the car a little slower to respond.

The first thing I will do is drive the car for 20 minutes at the base-line settings. This will do two things. For one, it will give me a basic lap time to work from so that I can ensure the settings I change are making the car faster, and for two, it will allow me to feel out what exactly this car needs improved for the track.

The first session was uneventful. I ran laps in the 1:37.7 to 1:38.4 range, and I found that while the base-line setup does handle fairly well at Mazda Raceway, it is sluggish during the corner entry and mid-corner phases, though it puts the power down fairly well on the exits of corners. The big problem is occasional chronic understeer. If you're not on top of your pedal inputs, you can easily find yourself sliding off the edge in turns 4, 5, and especially 10. I'd like to try and control that.

The first change I'm going to make is to add the rear anti-roll bar. Currently the front anti-roll bar is set to medium, so I will add the softest (thinnest) anti-roll bar in the rear to keep the rear of the car from rolling over in the corners. Normally a stiffer roll bar reduces overall grip, but I can't stand the idea of not having at least a soft one back there.

15 minutes later and I'm happy with my change. My lap time gaps got tighter, and my best time got improved by 0.060 seconds. The car responds much better at turn-in and in the mid corner, and the exit speeds weren't negatively affected - in fact, I gained a mile per hour on almost every straight. I probably won't do any more roll bar tweaking.

 Diving into turn 6 at about 90 MPH.

The tire temperatures indicate that the tire pressures and camber are set well. That may change once we start adjusting suspension components though.

The next change I'm going to make is to the toe settings of the car. Currently the rear has some toe-out, which will make things a little more "loose" feeling - the rear will want to step out a bit more. So I'm going to remove some of that looseness.

The change didn't really affect the times, but it felt better to drive anyway. That massive wash-out understeer problem is going away.

Now I want to play with the dampers. The track is very smooth, so the dampers are really only going to control the balance of the car, not really provide any bump relief. So I'll stiffen the bump (compression) settings of the dampers and leave the rebound (extension) setting be - I don't want to change the balance of the car.

5 laps later and I think I'm going to make them even more stiff. I'll put the fronts up to +30 clicks and the rears to +26 clicks.

2 laps later and I've broken my lap record by two tenths, with a 1:37.406. That time would put me 8th on the world record leaderboard.

Turn 8, the Corkscrew. Fun fun fun!

The stiffened dampers made the car much more responsive, and more stable with my driving style - the understeer issue is almost nonexistent, and fixing it hasn't made the car devilish to drive either. Most of my laps landed in the mid to high 1:37s, and the tire wear became much more even, both across the surface temperature wise and over all four tires in terms of tread depth.

Tomorrow I'll play with the ride height, but I suspect I won't find much time.

These simulators sure are helpful in learning how to set up a car.

Tuesday, April 12, 2011

(136) Bowling for dollars

So. The first race. How did it go? Read on my friends.

The first thing on order for the weekend was a full test day on Thursday. Test days are usually conducted in an open-track format, but since this was prior to a race weekend the quantity of cars dictated that the day was divided into sessions. The Miatas were all gobbed into one group so traffic wouldn't be a huge issue. Faster traffic like Formula Mazdas and D Sports Racers aren't a problem, they just zip by in the braking zone or on the straight and neither car is affected that much. The issues arise when you get very powerful cars that handle badly running with very good handling cars that don't have any power. It can get frustrating for both parties.

Anyhow, that wasn't an issue. What was possibly going to be an issue was the weather. For the week preceding the test day I was watching the weather carefully. But, even the night before the test, the report said rain was inevitable. I was hoping to be able to learn the back portion of the track in the dry, but rain wouldn't be a deal-breaker, just mildly annoying.

Turns out I needn't have worried. The weather was gorgeous if slightly cool.

Ric McCormick met me as the day began and we talked over my goals and how to go about coaching me. It felt good to work with him again after a few years of experience since the first time we worked together 3 years ago. I think, now that I have more experience, I can better appreciate and understand his wisdom. With a plan I hopped onto the track for the first of my 5 sessions.

 Strapping into the Miata. I really fit well in this car. Check out the monster of a rear view mirror I have.

The Miata felt pretty good right out of the box. Some pressure tweaking was required throughout the day but mechanically the car is set up very well. I used my "test" set of tires, which already had a few hours of running from being used in the driver school last month.

I wasn't too lost on the back portion of the track, fortunately. It's fairly simple, and I've watched tons of onboard videos showing it, plus I got to drive around it at slow speed during driver school.

Ric adjusted a few of my lines and my times dropped. I have a device on the car called a Rumblestrip. It's a little display that shows my speed, and when I pass the pit wall it shows my lap time if it can find a "ping" device, kinda like a transponder. It also shows my "split" time, whether I am in the process of setting a fast lap or not. If I'm ahead of my best lap, it shows a minus number. -0.35 means I'm going 3 and a half tenths faster. 0.30 means 3 tenths slower. It's incredibly useful when trying to diagnose the optimal line or gear for a corner because it gives instant feedback on how much time and speed I gained or lost. It's also shocking how much time you can gain and lose on an average lap, corner to corner.

A big point of the test day was gearing. The gear selections around Thunderhill are strange in a Miata.

Conventional wisdom says that if a corner falls directly between two gears, say, 6800 RPM in 3rd (200 away from the shift point) versus 4900 RPM in 4th, then the driver should use the higher gear since not only will it eliminate two shifts from the corner (eliminating possibilities for mistakes), it also encourages the driver to carry more speed through the corner. Trust me, you'll work your butt off to carry that extra 100 RPM in 4th to be "on the cam" at 5000 RPM on the exit.

In a car with reasonable torque, that is. The Miata has very little torque, and almost no power below 5000 RPM. You can take turns 2 and 9 in 4th if you really want to, but it's geared just high enough that you have reduced torque on the exit. During the test day, I ran turn 9 in 4h. Once I got totally up to speed as the race weekend went on, however, I started using 3rd. I gained 2-3 tenths doing that. Basically, 4th gear acted as a training wheel, encouraging me to push it harder and harder until I surpassed "gear selection equilibrium" and started going even faster by downshifting.

This isn't the case with turn 14 however. In turn 14, you can use either 2nd or 3rd. I always use 3rd. 3rd gear has enough punch coming out of there that, if done properly, gives you a good shot down the front straight.

Ian Cook of Cook Motorsports to fellow racer Mike Niemann: "I can't believe it! These Miatas are so light they just try to fly away!"

The other thing Ric encouraged me to do is left foot braking. I've been doing this on the simulator for years, but I've never used it in a real car outside of karting. I started using it in the corners where I didn't need to shift and, apart from braking a little bit too hard the first couple laps, it started working well for me. My left foot is more delicately tuned than my right is. Plus you can use the throttle while braking, giving you a smoother transition from brake to gas in those high speed corners like turn 1 which are very sensitive to jerky pedal work.

The other thing we talked about was my preparations, both mental and physical. I have a daily workout routine that I've been using for a number of months now. It's really helped me a lot more than the typical "30-minute workout every 2 days" schedule. Nevertheless Ric had a few things for me to add to it, including some balance exercises.

In all, it was a very good test day and I learned a ton from Ric. I dropped into the 2:09s in the final session of the day. Just as the last session got off track, a hail storm struck. Better timing there could not be.

Friday was practice and qualifying day for the first race, which would be held on Saturday. I continued to refine a few things that Ric told me to work on during the weekend. It was a fairly uneventful day, save for one thing - the tires.

On Thursday we bought a new set of tires to use in the race. The idea being that the test set I used in driver school and the test day were probably past their prime. I would "run in" the tires on Friday during qualifying and practice, and they would then be prime for the race.

Unfortunately for me, the Toyo RA1 tires we use in Spec Miata are street DOT tires that we shave down until nearly slick. That means that while they look like a race tire, they are still very much a street tire. Street tires are very hard rubber, designed for long life, and I totally underestimated how long they would take to "come in".

My fastest laps in morning practice were 2 seconds slower than on the test day. No ringing bells went off in my head because it was cold and everyone was setting slower times. I figured my car just didn't like the cold. There was a very loud squeaking noise coming from the right rear every time I went through a left hand corner. I figured something in the suspension was making the noise, and nothing felt wrong so I ignored it.

I mentioned the squeak when I got back to the pits and it turns out my right rear tire was rubbing the body work. How did I know? The tire had a little river of molten rubber running down the side wall and plastered on the inside of the fender. I touched it and it came off on my fingers like tar.

The tire in question. The darker blueish part just between the tread and the side wall is where all the molten rubber pooled and cooled into this super hard substance. You can see the streaks on the edge of the tread where it was rubbing. That's the trouble with running tires twice as fat as the ones from the showroom.

A quick roll-in of the bodywork and the issue was solved.

Then came qualifying. I figured my tires would be good to go for this session, but boy was I wrong. I ended up setting a session best time of 2:11.8. If I had kept my worn-in test set on the car, I might have done a 2:09.8, which would have put me 12th on the grid and 4th in class. Instead, I got landed in 20th overall, and 7th in class. Ouch.

Still, for the first race, that's not bad.

Saturday rolled around and it was time to grid for the race. It was early and cold, but I had my "good' set of tires on, the track had plenty of rubber from Friday, and I was ready. My team mate, David Allen, was just in the row in front of me. My plan was to carve myself a space to work on the start, and then I would follow David for a few laps to see if we could work together to advance through the field. I was warned by a number of racers that the field usually stacks up pretty good until about turn 5, which is where things get more single-file. I planned to start working through the field after that.

The Cook Motorsports/Premeir Auto Service and Team MiataKa paddock area. Richard Avril's yellow and black car in back going topless due to a broken rear window. In my opinion all the Miatas should be topless.

At the start everyone got stacked up exiting turn 15. This was good for me, because I knew what the leader was trying to do - brake hard, and then take off while everyone recovered. Once I verified that the leaders were on their way, I stepped on it and carried their advantage to the mid-field, leaving the guys behind me for dust down the straight, though not gaining much on the guys in front of me.

I held my line through to turn 5, where I linked up with David and started following him. I did this for a few reasons.

1. He's my team mate, and team mates taking each other out due to hard racing isn't cool. I wasn't going to push him hard unless I had a legitimate reason to go by him.
2. He's much more experienced than I am, and I would be able to emulate his demeanor and keep myself calm. The first race in a new car at a new track is very exciting. You have to do as much as you can to keep it from going to your head and making you act like a nincompoop.
3. The draft is huge in these cars. Plus I could keep serious competitors off his tail while he worked through.

Simply put, teamwork is better in any situation.

Fred Peterson in the red 9 car had other ideas though. He passed me going into turn 10, but I was able to get him back in turn 14 and continue watching David's back while he tried to get by April Halliday in the blue 36 car.

After watching this for a while, I realized David was having no luck. So I decided to go by him in turn 10, and hopefully he'd be able to follow me past April. Unfortunately that didn't work out as intended, since there was a spin in turn 14. I only barely saw the yellow as it was raised out of the corner of my eye. I had gone into turn 14 pretty hot, and that extra tiny little bit of pressure on the brake sent me into a big slide. I've recovered from big slides before. I had a full lock drift once out of turn 6 that I saved. But turn 14 has a little bit of banking, and the car decided to come around right as it caught extra grip from the slight banking, and it sent me shooting off the other way, thankfully avoiding the spun car, as well as the barrels on the outside. I lost the spot I had just gained from David, and now the purple 95 piloted by Bob Murillo was on my tail.

I pushed hard to keep Bob behind me, but as I caught back up to David I realized that I would not be able to hold Bob off if I stayed behind David. So I passed him in turn 10 again, despite David being very pointed about his defense of that corner. I shoved it up the inside anyway.

I then focused on catching back up to April since she had checked out with all the passing and battling going on behind her. Bob was pushing me hard after getting around David and I soon found myself close enough to start dueling with April. She ran wide in turn 14 and I tried to capitalize on it, going 2 wide through 15. That didn't work, and in hindsight it was kind of a dumb move, because Bob was able to capitalize on my mistake and motored by.

Bob's rear bumper was missing, and I found it very hard to get any kind of draft from his car. That bumper must provide a lot of the drag on a Miata.

Bob got by April later that lap, and then I squeaked by as well in turn 14. The chase was on. Bob had an SSM car just like mine, and I really wanted his spot.

I caught him up, but couldn't pass because the draft didn't work. After a few laps we caught lap traffic. I tried to stay with him but he used it more to his advantage than I, and he pulled a gap that I never recovered.

I finished the race 5th in class and 16th overall. David finished 6th in class and 21st overall.

I actually have a little treat for you guys. During the test day my GoPro actually died. It just stopped turning on, even with fresh batteries. Luckily, my instructor from driver school, Juan Pineda, was racing (incidentally he also got his first class win this weekend) and he offered to loan me one of the Contour HD cameras he sells.

So, I've got a full HD onboard film of my first race for you!

Race #1 onboard footage in HD! Be sure to click the "HD" button and watch it in fullscreen to get the best quality.

It really is a quite nice camera, and after figuring out how to edit the files it records I think I may buy one. We'll see.

I'm quite happy with my results from the first race. I think getting top 5 in a field of 17 cars in the class the first time out is a good start. 16th out of 47 cars overall is also very good.

The second race of the weekend was much less dramatic. I re-qualified 5th in class and 16th overall, the same as my finishing position in race 1, incidentally.

Unfortunately the camera ran out of juice on the pre-grid just before we rolled off for the race. Fortunately for you my race wasn't terribly exciting.

The start was much more organized, so there were more cars around me and I wasn't able to carve out a spot to work as effectively. I passed a couple cars and then got re-passed by a couple cars. Eventually things strung out and I mostly just raced on my own until a full-course caution came out. We re-started and again I got left mostly alone. Sad face.

My afternoon was livened up somewhat by another large slide in turn 14. Just as before, the banking caught my car and spat me out the other way. I went bowling and nailed one of the plastic barrels on the outside. My momentum carried me into the grass, but I didn't lose any positions because I was all alone. More sad face.

I finished the race 1 position better than I started, in 15th overall, but still 5th in class.

I've never been in a race with that many cars and I tell you, it was something. Seeing the field stretch way into turn 1 ahead of you while also seeing the field stretch way back into turn 14 behind you is something. And this is just an "average" size field. Next month at Laguna the field is likely to be even bigger.

It was quite an experience and, I think, a good opening to my career in SCCA.

Thanks to all the dedicated volunteers of the SCCA from car #78!

Friday, April 1, 2011

(135) The first car race...

On April 6th I'm leaving for my first race weekend in full size cars.

It's been about 8 months since I've taken the green flag in a "real" race with points and trophies on the table. Seems like an eon ago.

This will be my first time on the full Thunderhill layout. During the driver school, we only got to run the first half. Luckily, there is an open test day on Thursday that will give me a few hours to learn the back half of the course. I also want to hire a private coach to help me with refining the track. Update: Ric McCormick, the very first instructor I had at Jim Russell 3 years ago during my very first introduction to kart racing, will be coaching me during the test day. Ric has been teaching for over 15 years. It'll be very exciting to work with him again.

Then things get underway. On Friday we have a practice session and a qaulifying round. Then we race for the first time this year on Saturday. There will be another qualy session in the afternoon, with the final race being conducted on Sunday.

At the moment there are about 35 cars in the Spec Miata group which I will be running in. There are two Miata classes in the San Francisco SCCA region: Sealed Spec Miata, and Spec Miata T.

Spec Miata T is the faster class. The fastest SMT will probably be about 1 or 2 seconds per lap faster than the fastest SSM. The SMTs are built to the same specifications as the Spec Miatas in the rest of the country, with one provision: they must use Toyo RA-1 tires.

Sealed Spec Miata, the class I'm racing, is exactly the same as SMT in terms of suspension, tires etc, except for the engine and the chassis. SSM is limited to Miatas with 1600cc engines, so that means only the first-generation Miata is eligible. The engines are built and then sealed by MCE Racing based at Thunderhill. SSMs have about 110 horsepower, and SMTs have about 125.

SMT and SSM usually race together in their own group. There probably won't be any faster traffic for me to worry about as long as I keep my pace brisk. According to the entry list, at this point, there are 14 entries in SSM. Much of the SSM field will overlap with the SMT field. From what I've seen, SMTs and SSMs still race fairly hard even though they aren't really competing against each other.

I rate my chances for the races pretty high. I was fastest in driver school and I have a ton of racing education to draw upon, so I feel like I will be on the sharp end of the field. I'm very confident that I can learn the rest of Thunderhill quickly and place well in the races.

I have some more pictures from my weekend at driver school, take a look. See you after the races!

Exiting turn 8.

Following Juan Pineda, my instructor, over the crest of turn 5. From this angle it looks shockingly similar to the Corkscrew.

On the grid, being dwarfed by the Mustang and Porsche 930 next to me.

Racing hard with Juan.

Heading into turn 15 flat out.

Running wide in turn 8, but it's okay, it looks cool on camera!

All images credit Chuck Koehler.