Thursday, October 18, 2012

I went slow, and then I didn't go at all

This is the weekend write-up I never wanted to do. Last weekend at VIR was supposed to be the culmination of 7 years worth of performance driving. Instead it served as the ultimate disappointment and early end to my season.

I'd prepared for a solid year to do NASA's Super Comp school in October. I'd read the rules, prepared the car, waffled over just the right setup, and ultimately chose one that was slow, but stable. I even had a crew member for the day to make sure I got from the classroom to the race car, and that I didn't run out of gas at any point.

The day began well enough, with a bunch of classroom sessions and on-track runs. We spent 40 minutes at a time doing starts, restarts, short (half-lap) races, and drills that kept us pinned to one side of the track or the other for upward of 20 minutes.  It was grueling, but really eye-opening.

I felt extremely optimistic going into the final session of the day. I'd managed to pass at least one car in each of my sessions, and only one person passed me all day. It was really great, and all I had to do was make it through 2 standing starts, 2 rolling starts, and a practice race.

The first standing start was crazy. I launched the car pretty well (4000RPM clutch side-step, just like at autocrosses) and got a run on a Spec E30. We were supposed to race to the start-finish line at the south paddock, but there were no flags displayed there, so we kept charging until we saw the first flags, which were displayed at T14. I passed a blue Mustang under hard braking as we approached the flags, and saw another instructor gesticulating wildly as I pulled up beside him.

I couldn't tell what he was trying to tell me to do, so I stayed beside him through the turn. What happened next I can't explain. Whether I went stupid or half-blind or just chose the wrong pedal or what, I got on the gas as he got on the brake. Maybe I thought he wanted me to pass him. Either way, the moment I got in front of him, I realized I was boned. I had just passed a car under double yellow flags and failed the school.

I completed the remaining starts and restarts and got about 2/3 through the practice race before the car started acting up.  Coming onto the front straight, she just wouldn't accelerate above 85mph. Once I hit 5000RPM in 4th gear, there was no further acceleration. I dropped back into 3rd and came through Turns 1 and 2 and the car seemed to be ok-ish, just a bit off pace, but when I started up the climbing esses in 4th, the car was actively slowing down. I looked down and saw that my oil pressure gauge was reading 0psi, so I pulled off-line and coasted the car to the south paddock.

What blew me away, though, was that the car was still running. You can't run a car for a solid minute at full-crank with no oil and have it reward you with a stable idle. I figured the motor just really really liked me and I shut it off and waited for a tow.

When I got back to the paddock, I looked under the car for a big gaping hole in the motor, but there was none to be found. Oil was still on the dipstick, too, albeit just the teeniest amount. A light tug on the wire for the oil-pressure sender revealed that the nut had fallen off, and that I'd just lost the signal.

Cool, but why then did the car die?  I tried to refire the motor, but the starter wouldn't even click.  I grabbed the charger and got my first clue: the battery was 100% dead.

In a comedy of errors, I had managed within one lap to:  kill the alternator, burn just enough oil out of the motor to make it appear empty (it was only down 1 quart), and lose my oil pressure sender.

The next morning, after charging the battery for several hours, I was able to start the car, though it was now producing a horrible sounding knock from the bottom end. Add a thrashed bearing or rod (and/or crank) to the list. Fun.

So with a tanked motor, tanked alternator, and failed attempt at race licensure under my belt, we packed up and came home. It was, without a doubt, the single most disappointing automotive outing I've ever experienced.

I've already begun work to transplant the "spare" motor, but it's gonna be a long road ahead, and it won't be done in time for November, so the year is done.

But there were some take-aways from the ordeal. I've decided unequivocally that I will keep the orange car in aero trim and make it my Summit Point (only?) car. The diff ratio, aero, and suspension seem to work very well there. Stacey (the 'new' car) will be coming home from the builder within a couple weeks, and will receive the orange car's transplanted motor with heavy-duty forged internals. I'm going for torque & horsepower above all else with this one, and she'll be dedicated to tracks with longer straight-aways. I'm not completely optimistic that she'll be ready for February ($$$), but dammit I'm gonna try.

Friday, August 24, 2012

Another Month, Another Plan

So all of that stuff last month about building dedicated cars for each track?  Eh... Still sorta on the table, but it kind of limits what I can do with my stable of (potentially rentable) racing Miatas.

Last weekend was NASA Mid-Atlantic's Summer Breeze at Summit Point. It was far and away my best overall weekend of the season, with the best weather, turn-out, and camaraderie. Winning 4 tires didn't hurt, either.

I went to Summit Point with a plan. That plan was a bit hamstrung by the age of my tires (this was the 5th event on a single set of Hoosiers), but that kind of played into my hands just a bit.  Lemme 'splain...

The wing, as previously mentioned, is an anchor at VIR, taking a full 1-second improvement on the front half of the course and throwing it away in 4000' on the back straight. My plan was to switch back to last year's configuration, balance the car perfectly, and see if I could make an overall improvement at Summit Point just by driving better.  I was, after all, getting key data inputs like throttle-position and brake-actuation.

What I quickly found, though, was that even though we scaled and balanced the car to knife-edge perfection, there was just no grip in the rear.  New sticky Hoosiers can mask a lot of deficiencies in a suspension, but old ones cannot. The Spec Miata sway bars that used to feel so good and solid at preventing body-roll also place excessive duty on the tires. Again, that's fine when they're new, but at roughly 30 heat-cycles, not so much.

I tried to put down any sort of decent lap over two sessions and came out putting high 1:28.x laps. That's awful considering I'd done several high 1:26.x laps in April.

I also very carefully documented tire temps and pressures after each session, and the rears just weren't doing what I had hoped for.  Fortunately, I'd brought the wing and stock sway bars to experiment.

I switched back to that configuration, re-filed my class sheet, and hit the track again, immediately taking off almost a full second and keeping the car firmly planted in the rear.  The next morning, over the course of two more sessions I took off another full second, ending my weekend with a 1:26.862 lap, within 0.3 seconds of my personal best and on tires that had no duty-cycle left. And the crazy thing is, there was plenty more performance to be had.

So now I have a new quandary!  The wing is a proven benefit at Summit Point, to the point where I believe I have a reasonable chance at setting the lap record for TTE.  But it is also a proven boondoggle at VIR.

My plan for October had been to switch back to the beefy sway bars and just hope for the best in comp school, but then i realized that I'm taking exactly 7 points for aero.  What if I ran another dyno reclass for TTE/PTE with one star? That one star could represent a bump in horsepower or a significant drop in weight (I have about 70lbs of ballast in the car right now), or both.  No aero, compliant suspension, more horsepower, and less weight. Could that be the ticket, or will the car be too unstable at high speeds?

I must find out!

Monday, July 23, 2012

NASA Heat Wave at VIR

I find myself in a relatively unique position. I just had what I should call a very bad weekend at the track, but I came away with so many ideas swirling around in my head.

After finishing a very close 3rd on Saturday (by less than .2 seconds), I came a very distant 3rd on Sunday--1.5 seconds out of contention for 2nd. Both cars that finished ahead of me were running with significant advantages: new rubber and superchargers. My car, meanwhile, was running on tires that were first mounted in February, and dealing with residual high-idle and overheating issues and a suspension setup that's always just been guessed at--never properly calibrated.

I knew going into the weekend that a win was out of reach, and that 2nd place may not happen either, but still, it was a shock to be beaten so soundly on Sunday.

But I learned a lot. And I mean a whole lot.

I learned that ballast cannot go behind the rear axle. I didn't think it was a good idea when I did it, but I really didn't want to risk interrupting fuel and brake lines to mount it in the driver's compartment. I will fix that for the next event. At one point a car braked quite early and off-line in front of me, causing me to swing right to avoid his bumper. When I turned the car back to the left for the corner, the back end washed out. Not cool. I removed the ballast and ran with extra fuel to prevent that happening again.

I learned that my wing does, indeed, cause significant understeer at corner-entry. It was nigh impossible to get the car to the apex of T1, though I was able to carry more speed than ever before into South Bend (95mph), and brake even later for T14.

I learned that urethane bushings don't make a car faster, they just reveal inefficiencies in your suspension setup. I had an off-line entry into T4 that, when I corrected with a touch of oversteer, caused the car to skitter across the track in a very unsettling series of bounces. At one point the horizon began to rotate and I had to do some very creative steering to get it back under control. The lower esses are just an exercise in bouncing, though it doesn't seem to affect top speed. I may need stiffer springs & shocks in the rear, though experiments with tire-pressure should help resolve that question.

I learned that I'm running too much negative camber. I've had a tire pyrometer for years and have never used it. This time I had K pull temps, and inners were 10 - 20 degrees higher than the rest of the tire surface.

The most important thing I learned, though, is that my car simply isn't competitive for VIR in its current configuration. And that's got me thinking about my plans for the other car.  Bridget (orange) is very close to lap-record time at Summit Point, a track with significant time spent in corners. Aero is important at Summit Point, because without it, I cannot carry speed through Turns 3, 4, and 10, and braking into 1 and 5 are weak.  But at VIR, with a 4000' straight-away and a whole lot of time spent going straight-ish, the aero just holds the car back.

Last year I was just under 2:20 and seeing 118mph on the back straight, and 117 on the front straight.  This year I'm seeing 116 on the back and 114 on the front. My competitors are seeing 120+ on both. The wing is slowing the car down.  Worse yet, I had one of the supercharged Miatas behind me on the back straight, and he sucked up under my wing and passed me like I was tied to a tree. So not only does it slow my car down, but it speeds my competitors up. Decidedly not awesome.

So what to do?  Do I run a supercharger at both tracks? The Chute (T4) at Summit Point is scary, and I do not really want to run that track without aero. But I'm not really interested in doing full motor-swaps between events.

The solution may be Stacey (the new car I bought last November). Stacey is currently getting a roll cage, and her development track had been to run in Chump then TTD/PTD. But nobody's racing PTD, and the registrations for TTD are consistently slim.  So what if I built a Spec Vinny car out of her?  Supercharger, TTE* with shocks, springs, LSD, and Hoosiers.  One car for VIR, one car for Summit Point. One with power, one with aero.

In any other situation it would be a profound absurdity to consider, but I have two cars to run. And running the power car at VIR would save me from having to get dyno-ed for every single event, since temperature variations make a dramatic impact to horsepower.

Wednesday, June 06, 2012

Last Day of Kindergarten

Today is Alastair's last day of Kindergarten. We're super excited for him, but last night I cried a little.

He's gotten to do a whole bunch of amazing things this year, made lots of new friends, and excelled in his academics. In all respects a good start to his schooling.  But getting him to tell me about his day has been an epic struggle.  All I ever get is his behavior report, a list of his recess playmates, and maybe what main class they had that day (if I'm lucky).

So I was really excited when I found out they'd been keeping journals at school. I figured the contents would be very basic, and they were, but they were so full of insights into my little guy. Insights I hadn't experienced before, which tore me up.

I realized last night while looking through his pictures that I'm already losing him. I know his favorite colors are blue and black, but I had no idea his favorite animal was the cheetah, or that it had at one point been the lion.  Small details, but I used to think he told me everything.  I learned that his favorite farm animals are cows, and that he thinks they're funny. His favorite reptile is the crocodile, and his little pictures of them are ADORABLE. He loved the zoo and Disney World and has really enjoyed the time he's gotten to spend with K. He even included her in his description of his favorite event of the school year: their second field trip on which K was a chaperone.

The fact that there could be so many revelations in a book of maybe (maybe) 20 short sentences and doodles just floored me. How could he have grown so much? How could he have secrets? Why doesn't he share with me? Have I created a wall between us? So many questions to fill my soul with self-doubt!

I know he loves me, and I know he tells me what he can think to tell me, and that there's a TON of stuff going on in that little head, but I want so desperately to share in every moment of his brief youth. But I also want him to be independent. Being a parent is the most wonderful miserable experience.

But enough of that: today I am infinitely proud of my little guy. 9 months ago he'd never done a full day of school, and in 3 months he'll be a first grader! Today, however, he's a kindergartner, and I'm gonna squeeze him and love him like crazy.

Tuesday, May 01, 2012

NASA Spring Showdown @ Summit Point

What an amazing weekend.

I went into the 3rd event of the 2012 season with more questions than answers, and having done absolutely nothing to the car since March.  My tires were on their 3rd weekend, something I've never even considered with Hoosiers (they peak early and fall off quickly, typically dying near the end of the 2nd event).

But during the warm-up session Saturday, I knew I had something special.  I'd put the wicker bill back on the wing in fear of rain, but left it as flat as it would go (about -5 degrees).  And without pushing too terribly hard, I managed a 1:27.3, which was nearly as fast as my fastest previous timed lap ever.  Typically I could average a 1:28.5 or so, making me excited about the day ahead.

The one thing I kept doing, though was locking up the front brakes.  That had simply not happened with the higher wing angle, so I developed an unreasonable fear of late-braking, something that ended up costing me a track record.

In the 2nd session I pulled a 1:26.9 lap, my fastest timed lap ever by 0.1 seconds, and I knew there was plenty more.  Due to a scaling issue, I had to add 7 gallons before going back out, but even with that 43lb addition, I managed a 1:26.5 in the 2nd timed session.  Delighted with the results, I parked the car for the day.  No sense taking what was left of the tires away from Sunday.

And then came the weather.  For the rest of the day, intermittent sleet came down, though the temps were in the 50's, resulting in an extremely slick track that gobbled up cars left & right.

At the end of the day, we learned that an error in timing & scoring resulted in most TT drivers losing times from the 2nd session, which meant that my 1:26.5 didn't count.  I was crestfallen, but I got it on video and overlaid the Traqmate data for posterity:

It rained most of the night Saturday, so I figured we'd have a pretty green (and therefore slick) track in the morning on Sunday.  So I dialed in just a tidge of wicker (adding maybe 10 degrees--maybe) and put down a 1:27.2 lap.

Disappointed, I put it back to the original setting and went back out and ended my weekend with a 1:27.0 final session.

I was astonished when looking at data last night.  I had thought that 0.2 second penalty was the result of the wing.  In one lap, I could clearly see that I was ahead of my record, then lost it on a straight-away-- clearly the result of the wing.  But it wasn't.  With the wicker bill at ~15 degrees, I posted the fastest straight-line speed of the weekend at 116.88mph at the end of the front straight.  I didn't trust the brakes, though, and got on them 0.4 seconds too soon, then backed off the brakes about 0.5 seconds later.  Throughout that 1:27.2 lap, I consistently got on the brakes too hard and for too long, resulting in lower apex speeds by about 5mph, particularly at turns 3, 5, and 10.  And if there are 2 turns you don't want to screw up at Summit Point, they're 3 and 10.

I honestly believe that if I'd trusted the car a little more, I could have come in at a 1:26.0 lap.  The 0.4 seconds of unnecessary braking alone would have put me under the track record of 1:26.2.

All of this makes me extremely excited about getting back to VIR in July.  I think I've finally stumbled upon a setup that can take time off my laps, instead of adding to it.

I'd like to thank Elliott Tire, my amazingly supportive wife Katelyn for putting up with the weather, and my son for joining me this weekend.

Thursday, April 26, 2012

Would ya shut up about the stupid wing already?

I will, I promise. But this weekend I'll be at Summit Point, and they're calling for rain.  Rain seems to be the hallmark of the 2012 NASA Mid-Atlantic season so far, and one thing that's become blindingly obvious about the wing is that it's amazing in the rain (last month I ran similar lap times in the rain to what the racers ran--on slicks).  So dialed-in or not, it's staying on and may even end up with a pretty aggressive angle on the wicker bill.

I may not be excited about the weather or the incredibly small pool of competitors, but I'm pretty confident about this weekend.  Let's go to the track!

Thursday, April 12, 2012

A confession, of sorts

When I sourced a wing and a differential for this season, I didn't do my homework.  So often I've gotten away with either getting things right on the first try, or learning to compensate. So I let hubris guide my hand and just mounted the wing, figuring it would just work and I'd be faster. Whee!

Well I'm not.

And now, fully 3 months after putting the thing on the car, I'm reading and learning about how wings work. And the chances of "getting it right on the first try"? Incalculably small without doing some very complex math and having access to a wind-tunnel.

I learned after the first time I used it that the wicker bill was set too steeply, but only dialed it back to 50% in order to keep the downforce. I had considered dialing it all the way down for Summit Point, but now that I know a teensie bit more about How Things Work, I'm thinking I might be better off removing it outright.  I'm also learning that the angle of the wing, though it looks flat, may actually be entirely too steep.  It certainly becomes too aggressive with the wicker bill, which has a mathematically enormous planform at 3.375" chord * 56" span. That's too much for a Miata, IMO, unless I'm just using it for autocross purposes.

So my rant from the other day about removing the wing and building a diffuser...not gonna happen. Further research shows the Miata's rear pressures zone just isn't big enough to benefit from a diffuser, and the car's likely too high off the ground anyway.  Any reduction in lift would be insignificant compared to the points-penalty assessment.

Aero is difficult and confusing. Were it not for the dramatic and easily-observed impact it's made in my braking, I'd ditch it entirely, but I know there's more to it than just looking bad-ass. And I know that getting it right will produce good downforce with minimal drag. I just hope to get it right(er) this season.

Tuesday, April 10, 2012

NASA March Madness @ VIR

My lap times are going the wrong way.  Call it fear of aggravating my appendectomy wounds, call it fear of the damp conditions, the result is the same: I'm getting slower.  And data is telling me something I really didn't want to know.  It's the wing.

In February, I set an aggressive angle on the trim tab because I could only get the foil to go flat, even at max elevation. This was due to the slope of the trunk and limited adjustment options on the wing itself. I couldn't get the car past 114, which was off its previous best of 118mph and clearly not working.  So I dialed the tab back to 50% and got a little better performance without losing grip.  But I'm still almost 2 full seconds off last season's pace.

I adjusted shift points, drove harder through South Bend than I ever have before, and took 3 full seconds off my braking PER lap.  The car rockets up to 90mph like it's been shot out of a cannon, but hits an aero wall.  Acceleration graph comparisons over distance show a dramatic fall-off at 90, so it's clear I need to dial that trim tab down even further, but I don't know that it will be enough to keep the rear end planted and regain any time.

In spite of the high 2:21's, though, I was still able to eke out a win both days, finishing just 0.3 seconds ahead of second place on Saturday, but cementing a firm lead on Sunday before the rain ruined the afternoon.

Overall it ended up being a very good weekend, and I have to thank Hoosier for their generous contingency policies, but it's clear I have some work to do to get the car to go fast again.

I'm currently debating replacing the wing with a rear diffuser and going back to my beefier sway bars.  The stock ones do not feel planted at all, and they're much noisier when pushed to the limits.

Monday, April 09, 2012

In which I have surgery and a wreck

Three weeks ago (hard to believe it's already been that long), I got up nice & early on a Sunday morning to get the family ready for church. I fed the boy and went upstairs to get dressed, but just wasn't feeling quite right. I tried waiting it out, but it just got worse and worse.

By 10:30, it was clear we weren't going to church. I felt like I'd swallowed a ball of hot glass shards. I sent myself to bed, but didn't sleep. I migrated to the sofa to watch all the racing on TV, but couldn't even focus on that. After 4 hours, the pain hadn't moved or abated at all, and I'd tried to vomit. While successful, it did nothing to alleviate the pain.

Off to Patient First I went. PRO TIP: don't go to Patient First.

I waited in the lobby for an hour, then was told to stand upright on the scales. I couldn't, but that didn't mean I didn't have to try. After another 50 minutes of waiting, I was told that while I may have appendicitis or pancreatitis, I probably just had the "stomach bug" and should either go home or to a hospital for more tests. Yay Patient First! 2 hours lost!

30 minutes later I was sitting doubled-over in the ER waiting room at St. Mary's with my wife and son, who was terrified that I was dying right in front of him. By 6:30pm I was in a treatment room, and my parents were on their way to take Alastair for the night.

By 9:30, I was no longer in any particular pain, though there was some tenderness in my abdomen, leading the medical team to believe that I was facing appendicitis, but they wanted to run some more tests. X-rays were done at around 10:30pm, and a CT scan at 1:30am confirmed it: appendicitis. God bless her, K stayed for the whole shebang. I sent her home twice to let the dog out, and had to force her to go home for the night when it was time to get moved upstairs to my more permanent room.

At 7am, I got a wake-up call from the surgical staff telling me that I was going to have an appendectomy. Up until that moment, surgery had been one of my biggest fears. But having not been able to keep any food or water down since 10:30am the previous day, all I cared about was getting medically fit enough to drink a glass of water. Nothing else mattered to me (well, except whether or not I would get to go racing that weekend, but more on that later). I went back to sleep, and woke up with K by my side. We had a couple of visitors, and at 10:30 the doctor came back to tell me that I was either going to have surgery at 11am or 1pm.

20 minutes later they were wheeling me downstairs to the OR, joking with me about delicious foods I was in no condition to eat.

I remember being in the prep room for about an hour, listening to an elderly fellow become increasingly hostile to the medical staff because he hadn't bothered to keep track of his own health. Then they came for me, and I woke up groggy in a recovery room. This surgery stuff is apparently quite easy.

I got to my new room in the surgical ward and drank. Oh how did I drink! And I ate Jello. Quite possibly the best thing I'd ever tasted in my life! A couple of hours later I took my first tentative steps, and through the night got up repeatedly to walk around the ward, my wife ever at my side.

And then, the next morning, with no fanfare at all, I went home. And that was it. Of the percocet I was prescribed, I took only 3, waiting for the pain to double me over, but it never happened.

By Thursday I was out hitching the trailer and loading up for a weekend at VIR.

All of this sounds very uneventful until you consider that my actual plan was to climb into a race car 5 days after surgery and try not to kill myself. In the rain. On slick tires. Oh, and I would be instructing, too...riding in some person's car whom I'd never met and hoping that they'd also not kill me in the rain. I'm genius.

As it happened, getting into and driving my own car was no big deal. The rain let up and I got a little brave late in the first day, eking out a 0.3 second victory in my class, and having a great, if wet, time in my student's car.

Sunday, however, 6 days after surgery, I had my first ever wreck on track. My student misjudged his entry into a turn, tried to correct mid-turn, and didn't quite succeed. Off we skated into the grass, straight at a tire wall. Realizing the belts were directly on top of my still-healing wounds, I sank down in the seat until my knees were resting on the dashboard and waited for it. The hit honestly wasn't bad. There was no pain, no blacking out, not even a significant whip of the neck (no HANS). When we got back to the pits, it was evident how lucky we'd been: no structural damage to the car, and the airbags didn't deploy. So we couldn't have been doing more than 10mph or so. I got lucky.

And the best part? I won that day, too.

Oh, and I didn't die in front of my son. Hopefully that will make it clear to him that it's possible for someone to go into the hospital and come back out alive, healed, and capable of resuming a normal life.

Wednesday, February 22, 2012

NASA Lap Dance @ VIR - First Win of the 2012 Season!


That's my best time of this past weekend. It's a full second off my previous best, and in arguably better conditions, but so much about the car has changed since October, and it's taking some re-learning. And of course, there was also The Incident...

I've covered some of the changes I've made during the off-season.  The wing, the new differential, the sway bars...  All told, they make the car very different to drive.   The clutch makes some small amount of difference, too, but my goals for the weekend were 2:  learn how to drive the new configuration, and experiment with wing settings.

I went into the weekend knowing there weren't enough registrations in my class to worry about actually competing.  The two other drivers that had signed up wouldn't bother competing if we didn't have 5 people total, so I anticipated an easy win and plenty of time to play around with the car.

What I didn't anticipate was losing a wheel in the warmup session.

I missed the wall by inches, but was fortunate to find everything I needed to get back on track within a couple of hours.  All told, I flat-spotted a rotor, lost 4 lugs, 4 studs, a wheel, and a backing-plate.  No other significant damage, and I had been running on last season's tires just to save equipment costs.

Also fortunate was the fact that I only had one student, allowing me all the time I needed to get repairs done without impacting anybody else's day.

When I got back on track, the priorities of the day had shifted to:  putting down a timed lap, and making sure the car was safe.  It was, and I slowly worked my way up to what turned out to be first of five, enough to win a tire!

Sunday was cold and wet, and only a very few people even ventured out in the TT sessions.  Of those, only the first session was dry enough to put down any sort of hot lap.  I settled for a 2:25, but it didn't matter because I was the only car in my class to go out on track all day.  So I got a win by default. It may not be glorious, but it's still 100 points for the 2012 season.

Next time to the track will be March 24 & 25.  I'm still looking forward to the opportunity to test the wing, but after pulling data and comparing with my previous best laps, it looks like there are a couple of seconds to be gained over my personal best (2:19.895).  For one thing, braking is far more stable, with no over-steer at all, and an average of 0.2 seconds reduction in the braking zones, coupled with slower corner-entry speeds.  Aside from when I lost that wheel, the brakes didn't even hint at locking up.  On the down-side, I'm running out of puff at 115 with the aggressive wing angle, and I need to learn to get off the brakes.

Overall I'm extremely happy with the setup.  With a little tweaking and a lot of seat time, I think it'll be a strong contender for the season championship.

Can't wait to go do it again!

Tuesday, January 31, 2012

A Little Experimentation

As I've been preparing for the start of the 2012 season, I've had a lot of questions about the changes I'm making to the car:  new differential (4.30 and urethane bushings), beefier clutch, wing, and moving back to stock sway bars.  Will the new setup work? Will it take 2 or 3 events to figure out how to drive it? Will I trust it too much and stuff the car?

There are a lot of moving parts up there--no real scientific method was used, other than trying to maximize the allowed points for my class. The wing was the most obvious aero choice, but it's not being accompanied by any corresponding front aero, so the biggest question I had was if I was seriously upsetting the handling of the car.  Most folks tend to agree that adding down-force means adding spring-rate, but that's not in the plan or the budget, so...eek?

Last night I had an idea.  One that's probably been done by countless others, and with better results, but it was new to me.  I fired up Gran Turismo 5 on the PS3, hooked up the PlaySeat & Logitech G25, and built a '91 Eunos Roadster to match my real car's configuration from last year (except for that whole 1.6L ~ 1.8L thing):

Power:  ECU, header, exhaust, intake
Suspension: -20mm ride height, -2 deg camber, 0 toe, 12.5kgf/mm front springs, 5.8kgf/mm rear springs, 7 front sway bar, 4 rear sway bar
Tires: Intermediate racing
Drivetrain: stock clutch, semi-racing flywheel

I added ballast and moved it rearward to achieve 51/49, and biased the brakes forward 7/5.

The car was nearly undriveable.  Heavy braking resulted in an extremely twitchy tail (just exactly like in my real life car), and it took all my concentration to get the car around the High Speed Ring without crashing.  That's ridiculous, as it's one of the easiest tracks ever. The best lap I could manage was a 1:26.3, and I was actually starting to get into a consistent rhythm.

So then I went and updated to this year's intended configuration:

Power: same as a bove
Suspension:  same, except sway bars:  2 front / 2 rear
Tires: same as above
Drivetrain: single-plate clutch, semi-racing flywheel
Aero:  Wing w/ downforce set to 13 (an intermediate setting)

I expected to have drag issues on the straights, but didn't. I can't decide if this is a limitation of the game or because speeds are not truly significant enough in a Miata to really affect top speed, but the difference in the corners was immediately noticeable.  No longer did the tail want to swing out under braking, and the steering was a tick heavier entering corners.  I've notoriously had a habit of tossing the car into a corner and powering out, but the end-plates on the wing prohibited that.  I could only pour the car into the corners, which is a good thing.

Ultimately, after just 3 laps driving with the new configuration, I'd taken almost 2 full seconds off my lap, and was far more confident entering turns 3 and 4. I was able to carry a full 10mph more through turn 4 and get on power far earlier in turn 5.  I only put in about 6 laps, but was turning consistent 1:24.7 laps.

That's a 1.6 second change doing nothing but adding downforce and reducing sway bars (forgot to change the old configuration to a 4.10 rear end). I'd say it was better than expected, but it's hard to say how well the video game will translate to the real world. But right now I'm feeling a little more confident in the changes I've made.  In fact, if I scale the 1.6 / 1:26.3 to ??? / 2:19.8 (my fastest at VIR), I get a 2.59 second gain, or 2:17.2.  That's huge, and could make this the best year ever.

So now the question remains:  is GT5 a good enough simulator to test real-world performance mods?

UPDATE: The gearing in GT5 was completely wrong for a stock Miata. After correcting it and updating one configuration for a 4.10 rear, I re-ran the test.  With a little practice I was able to get the old config (no wing) down to a 1:24.9, and the wing config down to a 1:24.3. It will still carry a full 10mph more through both T3 and T4, but the gearing and wing offset each other everywhere else.

Friday, January 13, 2012


Next weekend my little guy will turn 6. I am excite.

The guy's had a big year, with two trips to DC, the Inaugural (or only?) Baltimore Grand Prix, the advent of a step-mother, and the start of big-boy school.  He got a dog, came to the track for two race weekends, spent a bunch of time in the mountains with his grandparents, and made lots and lots of friends (including his first negative-influence friend).

He's seen all the Star Wars movies almost as many times as I have, and can damn near match me at Star Wars Trivial Pursuit. He's into video games--particularly the Star Wars and LEGO titles.

And this morning he called me out.

Every day I ask him how his day was, and every day getting him to tell me is like pulling teeth.  "It was good."  "Green frog today." (that's how they track behavior at his school)  But I want more, and so begins the daily ritual of questions:

1. What class did you have today?
2. What did you do at recess?
3. Did you eat all of your lunch?
4. What did you do at after-care?

Invariably I'm met with one- or two-word answers, and it drives me mad.  So this morning we were talking about how much I want to know about his day, and how I can't be there to see all of these things and therefore have to rely on what he tells me to paint a picture.  And he replied:  "But when I ask you about your day, you just say, 'I worked.'"

Boom. Served.

And now I realize I have an obligation to be more open with him. How it had escaped me up to this point is beyond me. Maybe I just figured he was too little and wouldn't care or understand, but he has a genuine interest in knowing about my day, and I'm seeing the reflection of my answers in his.

And so, when I get home this afternoon, I'm going to sit down with my son and tell him about all the great things I saw on 9gag today.