The Beauty of Data Acq. Cliff Notes: Data Acq is amazing for showing where you are leaving lap-time on the table. Traqmate is easy to use. Shifting “properly” makes up a shocking amount of lap-time. One tenth of a second going into 5th gear for 5 seconds is nearly three tenths per lap. First I need to thank the guys at Traqmate, particularly Andre Surles, for their wonderful Traqmate GPS Data Acquisition System. Second I need to thank Campbell Haigh for pursuing his dream and having TopSpeed build him a “race” car, and employing me to instruct him on how to drive it well. Finally we need to thank Carolina Motorsports Park and Palmetto Motorsports Club for their great track and skidpad. Campbell had rented my Spec Miata and my 2.5RS for Siegel Racing Driver Education Clinics at Talladega Gran Prix before we built him his ’95 Impreza L / ’06 STi hybrid. It’s a car of many names: “Speed Freak (his name for it) / Trk Str (his license plate that we call Trickster) / Lucy 2 (it’s nearly a match to TopSpeed’s ‘Lucy’).” This past Tuesday was his only 6th time on track and his learning curve has been impressive. I have always preached the benefits of skidpad time for new drivers or even experienced drivers with new setups. There is just too much stimulus on a race track for a new driver to process everything about being “on line” and being “on the limit” at the same time. You can easily slow down and safely learn the line without being on the limit, but it’s really hard safely to learn about how a car behaves on the limit, regardless of line. That’s where the skidpad comes in; there is no “line.” You just set yourself up near the inner edge of the skidpad and go to town playing near, on, and over, the limit. Campbell had progressed well his first few times on track but was understandably (and intelligently) wary of putting the car on the limit at 100+mph in most corners. We had talked about getting on the wet skidpad and finally made it happen that Tuesday near lunch. What was interesting was that while the car was well balanced on the dry track, on the wet skidpad it had terminal understeer. It had been quite capable of being rotated with trail-braking on the way in or with excessive throttle coming off the corners, but lifting hard on the wet skidpad wouldn’t get the tail out at all. It seems that we had gotten the car balanced by running a significant amount of front camber (3.1) and that the wet skidpad wouldn’t let us get enough roll to make the front grip. We considered taking some camber out, but decided to try inducing oversteer with the e-brake It worked so well that we spend the ENTIRE 60 minutes sliding around the skidpad. We changed direction a number of times and got Campbell to the point that he thought he was ready to go drifting We’d had the Traqmate for previous events at CMP. Campbell and I had gone over the data and discussed where he was leaving time on the track at length. At that point it had always been easily apparent while doing in-car instruction where he was leaving time. After the hour in the skidpad, we got back on track and his 3rd lap was SIX SECONDS faster than his previous best. That’s right, about 6.0 seconds! For $75 and one hour he picked up six seconds. That’s the most lap-time/$$$ ever. This is where the data acq really shows its strength. There were some places that lap that I could tell where he was leaving a little time, but it’s hard to say exactly how much time is being left where when somebody is running pretty well for one “golden” lap. The data let us know that he was still leaving just over three seconds on the table… time to start to really digging into the data. It turned out that a shocking amount of time was being left on each upshift, particularly the 4-5 upshifts. I almost always drive like I’m driving an endurance event; I try to be consistent and easy on “my” equipment. I can “turn it up” and put in a “kill” lap when there’s a good reason, like a Time Attack event or to get the data of what a fast lap can be, but generally I’m taking it easy on the equipment. Hence, I don’t ever “rush” the shift; I try to shift quickly, but not faster than the synchros and revs want to let it happen. It’s actually faster than some people that try to man-handle the shifter, and I basically NEVER miss a shift. Even if I might be able to force it a little faster, not rushing pays off over the long-run verses trying to shift faster and possibly missing a few shifts. Campbell also doesn’t rush the shifts, but I had noticed that sometimes the shift took long enough that the rev’s had dropped further than necessary to make the shift. Going over the Traqmate data showed that his 0.10 second slower shift meant that he was leaving a full 0.28 to 0.29 seconds on EACH of the 3 main straights. That’s right, about ONE tenth of a second slower shift translated to almost THREE tenths of a second of lap-time after being in 5th for just over 5 seconds. There were a few other points on track that it was nice to be able to see exactly how much time could be gained, but they were more obvious when we were in the car. The other biggest gaps were a few corners that I slowed a bit more on the way in and was able to get on the gas earlier on the way out. We’re going back to CMP on the 24th, so we’ll see what the Traqmate can teach us then. Siegel
Nice write up Scott, I really need to get out with you on a larger track than TGP. Any SRDEC's going on at CMP or Roebling in the future?