The Indigo Sports flywheel's effects were immediately noticeable. The engine now revved very freely and felt a lot more responsive. The upgraded ACT clutch was also performing as advertised with no grabbiness and smooth engagement.
The real test, however, was yet to come
Test 3 The Skid pad (Modified)I arrived at the track to find Jeff eager to get down to business. We gave the car another careful check to make sure nothing had vibrated loose on the drive over. We started out with the tire pressures set at 38 psi in the front and 35 psi in the rear. The Toyo RA-1 tires are designed to perform at their best around 200F. We would be checking the temperature throughout the tests and tweaking the pressures to make sure we had the temperatures optimized. We also reset the JIC shocks to # 11 on the front and #9 on the rear. Once we had finished checking the car over we headed to the skidpad to get some hard data.
As Jeff started building up speed in the 240 it was obvious from the sidelines this was now a very different car. Jeff's speed was noticeably higher and the car was cornering nice and flat, with none of the spectacular body roll that was evident in our "stock" tests. As Jeff reached the outer limits of the adhesion envelope I could see him balancing the car on the throttle, and, after noting the times on several hot-laps, I waved Jeff in and we immediately checked the tire temperatures all around.
Bingo! Right on the money. The front tires were showing around 205F and the rears about 197F. Not perfect, but well within the specs. We crunched the numbers and recorded a best reading of 1.08g. Amazing. Our 240 was definitely performing as well as we had hoped. I asked Jeff how the car felt.
"It's really not the same car," he said. "It corners nice and flat now, and the tires are extremely predictable. The most noticeable thing to me is I can now feel everything that is going on. Excellent feedback and the car is really well balanced. It should be a lot of fun on the road course."
Before we let Harrison loose on the track, we ran the skid pad tests again in the opposite (clockwise) direction and recorded a continuous reading of 1.078g. Another check of the tire temps showed we were still within specs, so we noted our results and headed over to the road course.
Test 4 The Race Track (Modified)Having achieved such good results on the skidpad we were eager to get onto the track. Jeff donned his helmet and racing suit and I gave the car another quick look over before Harrison eased out onto the track. Harrison made a couple of "70%" laps to get a general feel for the car and then started to pick up the pace.
The first hot lap stopped the timers at 1:31.77, with an average speed of 66.68 mph. Pretty darned good, but the next lap was even better, a 1:30.60 at 67.54 mph. The following lap was a little quicker at 1:30.55. Our conversion was obviously paying dividends. I signaled Jeff to pit so we could check the tire temps and get his first impressions.
Jeff was grinning from ear-to-ear as he pulled in. "What a blast," he said as he pulled off his helmet. "I'm amazed at the difference. This is a lot of fun. The car feels really good all around. I noticed a little understeer on the initial turn-in, but nothing like before. Also, it pushes a little exiting the turns, not badly, but enough to mean I have to adjust for it. Traction is excellent overall and the spring rates feel right on. The car is so much easier to drive at the limits now and all of the sloppiness has gone away."
I asked how the upgraded brakes felt.
"Not a problem so far, although I am nowhere near the limit yet. We'll see on the next session. I would like to try adjusting the tire pressures a little to see if we can get rid of the understeer, however."