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.
Thursday, October 18, 2012
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!
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.
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.
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