There’s an old saying: there are million ways to lose in drag racing. It’s been true for us, we’re finding all kinds of ways to lose, at least in round two.
We’ve had a remarkable run of success, especially for a team that’s been racing for less than two years. We haven’t lost in round one in the last seven races, since early May, and that’s wonderful. But the only way we’ve made it past round two is via a bye or a no-show. And we have found a lot of different ways to keep that ugly streak alive.
For a couple of months we have struggled with a terrible stumble when the throttle is floored at the line. Instead of smoothly going up to the RPM we want to leave the line at, the engine would gasp, stumble, and burp, then get up to speed. The graph here shows you a good run, in green, and the stumble, blatantly visible in red; the vertical line is the green “go” light. In a sport where hundredths of seconds are a lifetime, clearly a delay like this is a problem.
Green is a good run, red is not
But as you can also see from the graph, in the worst cases the engine would never even make it to the desired RPM before it was time to go. So the whole run would be messed up, far too slow, and we’d lose in a big way. Ugh.
The real killer of this problem is that it wasn’t consistent. One time we’d get a great run, the next it would stumble badly. As I stood at the line, I could hear it gag, and know we were in trouble. Then we’d look at the data, and see clearly the issue — we love the Racepak V300SD data recorder, it shows these problems in glaring clarity. No guessing why we ran so badly, just look at the graph.
We fought the issue for months. We tried bigger accelerator pump squirters, bigger and smaller air bleeds (both idle and intermediate), even changing the way Em hit the gas. Nothing worked consistently. At the Seattle national event, we had it badly on the first time run. I called Patrick at Pro Systems, our carburetor guru, and discussed several options. But debugging problems at a 2000 mile distance is hard.
While trying to adjust the level in the float bowls, I asked our friend Rick Dearinger for help. He discovered that the rear bowl just kept filling, and flooding the engine. Sometimes. We took out the needle valve to check it. And there it was, a chunk of rubber blocking the valve from closing. Sometimes.
Simple Hole, Complex Problem
The real kicker was that I recognized the piece of rubber. It came from the fuel line I had installed to solve another problem, the engine was stalling at the end of the track under hard braking. That rubber line connected the two float bowl vents, and it needed a vent hole cut in it. I was sure I had cut a nice clean hole. And yet the little piece we found was a dangler from that cut hole. Ugh.
But wonderfully, removing that little piece of rubber completely solved the problem, and it ran consistently, and perfectly ever since. Thanks Rick! We fixed the problem just in time to get a great second test run in at the Seattle national event. Then, as Em noted, we went out and beat Rick in round one. Sorry, Rick…
Leaking CO2 System
We were so excited that we had won a round in a national event, we missed the fact that we had a leak in the CO2 system. We had noticed it before the first round, but we needed to rush to the staging lanes and we had enough for round one. Unfortunately, there was not enough for round two. But we were so giddy, and rushed, for round two, we didn’t fill it. So we found another way to lose — no CO2, no throttle stop, and no shifting. Ugh. And our losing in round two streak was intact.
Then we went on to Mission, British Columbia for both a Pacific Northwest Super Comp Association race and the Canadian National Open event. We showed up for testing on Friday, and made some wonderful passes. We are getting a handle on tuning the car.
We still had the nagging CO2 leak, but constant vigilance and topping off the bottle kept it at bay. These kind of leaks can be tough to find, usually you listen for a hissing. At the track, where it’s more than a tad noisy, this can be hard. I recently had some quiet time at home, found it, and fixed it. I also bought some bubble leak detection fluid, so that I can find and fix these at the track.
But in the true spirit of “if it’s not one thing…”, we had another problem at Mission. The dreaded red light. We had all red lights in our first several passes. Usually I just write this off as something Em can fix:, settle her nerves, add more time in the delay box, something.
Another Red Light in Mission
But this time it was serious. These were not just red by a few thousandths of a second, but red by a lot, like several hundreths of a second. Sure we could add that much delay to the box, but there was something else wrong. We’ve never seen red like this.
While we worked to figure out what the issue might be, we had racing to do. We ran the PNSCA race on Saturday just putting a whole lot in the box and hoping. It worked in round one, but we lost in round two with a red light to our good friend Ed Hauter. Again, the round two jinx got us.
After much discussion with friends, we determined that the car was hopping out of the staging beams. There are infrared beams across the track that control the start and measure the times all down the track. At the starting line they are just an inch or so off the ground, down track they’re five inches off the ground.
The way you determine when you’re “staged” (ready to race) is by blocking those beams with your front tires. That also is how they start the clocks, when you leave that beam. Normally, you leave the beam by rolling forward. After careful observation, I was able to see that the car was actually doing a small wheelie (lifting the front wheels) out of the beams. That’s much faster, and was what was triggering our red lights.
Just Right Lift
Normally you want just a little lift (see the picture). The left wheel will always come up higher, the torque of the engine twists the frame, so you want to look at the right wheel. This picture is perfect, just a tiny bit of lift on the right front. But the Mission track was stickier, the car was running great, and that right front was coming up several inches. Enough to leave the beams, enough to make a red light.
The only way we could think of to solve this was to add weight to the front of the car. But we didn’t have the time or equipment to do that in the pits. So on Sunday for the Canadian National Open, Em put .050 (aka “a ton”) in the delay box and we went up for first round. And it worked. We had a perfect 8.900 pass and Em had a .005 light. Of course, this was really a .055 light with the delay… But we won, qualified #1 in the field, and went on to round 2.
Of course, that .005 was too close, so Em put .060 in the box, figuring a .015 light would be great. And, if you’ve read this far, you can guess the next chapter of this story. The weather was sweltering, the track was slipperier, and the front end didn’t hop up quite as much as it had all weekend. So her otherwise good .020 light turned into a glacial .080 light with the delay, and we lost in round two. Yet again…
Emily, Jason, Jack, Jenna, Chris
Home again, with a chance to fix things, I had a great talk with our old friend Jack Beckman and he gave me several solutions to the wheelie problem, without adding weight. As Jack said “why would you take a wonderfully light car and add weight to it?” We already have trouble with the car bouncing on rough tracks and return roads, why make it worse? And adding weight is a crap-shoot. How much is enough? How do you tune it? It’s a very clumsy tool.
Instead, Jack gave us two other ways to solve the problem, both easier and more tunable than adding weight. But I’ll save the details for the next blog. When we’ve actually fixed it. And maybe won a round two…
We’re headed into the next race in Bremerton (our local track) next weekend, the 15th and 16th with many things fixed, and a renewed determination to fix our round two jinx. Hope to see you there.
