The Test'n'Tune:
So I set forth to test some things on my car before Nationals that I hoped would make a substantial difference, you know things like tire pressures, sway bar settings and in general get some seat time in the car. Upon arrival to the Test'n'Tune I realized I forgot to bump up tire pressures to work them down. A quick drive to the nearby gas station should have cured that issue but their air hose was mysteriously gone so I had to deal with the tire pressures which were at 31 PSI front and 27 PSI rear.
One of the things I wanted to do was to dial out some of the oversteer I was having at the Midwest Divisional Championship that made the car so hard to put power down with so I wanted to mess with swaybar settings. It was plenty hot out, plenty humid out, and well, I only tested one other swaybar setting. The front bar got moved to full stiff and I dropped nearly a half second of time on the course and the rear end was glued enough to the ground to put power down but not so much that the car wouldn't rotate.
At this point I was basically done testing and tuning the car and Neal Tovsen and I flipped rides. I ran about .75 seconds off his fastest time in his BMW and he ran .6 seconds off his fastest time in his BMW in MY Mustang!!!!!!!!! Whaaaaaaaaaaaaaat? His data showed that he was leaving time on course in his BMW to the tune of about .4 of a second so Project Tilty being 1 second off a BMW with a good driver was still a bit of a shock but a reasonably good sign? More importantly was that he felt the car was very well balanced and he was shocked that it had as much grip as it had. He felt the cars had something to show an Evo in STU.
After what seemed like 15 runs, I called it quits and drove home so I could flip the tires front to rear, fill them up with air again (but maintained that same 4 PSI split) and come back the next morning for the actual event.
Solo Points #5:
Sunday was starting out to be a good day with a good nights sleep, reasonable morning temps (which didn't hold through the day), and a co-drive to look forward to! Dave Whitworth would be meeting me in Lincoln to suffer an agonizing day of co-driving with the most spaztastic and uninteresting person in Lincoln (me :P) and hopefully between the two of us we could learn something new. I know I got some pretty good tips of things I've been feeling since the start of the season in terms of spring rates and the likes.
The course would be a most of the Test'n'Tune course run backwards with the finish changed up. The course had a lot of critical braking points in it that if you got on the brakes too early or too late you'd lose time so this was GREAT practice for braking correctly. I think I'm starting to get a feel for the car's grip level and there are some "got ya!" course design elements I'm getting more comfortable with that are really separating my times from those who are faster when done wrong.
The course itself was designed, in a hurry, by one of our top drivers who just so happens to be driving a Miata so the course had a decent amount of Miata friendly elements (like the 4 slaloms) and some digs to give the power guys a place to use the power to pull them out of the corner. I'll get the map up later and update this post.
Run #1: After moving the swaybar to full stiff, I expected the car to be pretty well balanced but in reality the car was pushy, big time pushy. I did my best to drive around it and cracked out a 63.356 but snagged a cone in the second major turn around (greater than 90º left hand turn) which pulled the time to a 65.356.
Dave's run #1: Dave basically confirmed what I had observed. The swaybar change added way too much to the rear end of the car and it was plowing like a dump truck. We tried some tire pressure changes, bringing the fronts down and letting the rears climb for my next run. His time was a 65.283 but he clipped a cone for a 67.283.
Run #2: The tire pressure change made a substantial difference in the balance but it was still pushing in the high speed stuff. We would change the front tire pressure down again and let the rears continue to climb. The pressures started at 35/30 and were now at 31/32. I managed to make this a clean run and came in with a 63.355 (pretty dang consistent time wise, a theme for the whole day believe it or not).
Dave's run #2: Dave came in with a 63.414 but dirty again, this time with two cones for a 67.414. He tried explaining a little to me about how the car in the slaloms felt like he had to wait for the fronts to do all the work and that the rear was just too planted. He continued on saying that the car would slalom just fine but the corner after the fronts were hot enough that they would be just a touch greasy and the wouldn't have the same grip as it did in the slalom. We stabilized the pressures at 31 front, 33 rear and upped the rear rebound a quarter turn.
Run #3: The car felt better again, the combination of a touch more rear rebound and the slightly higher rear PSI helped balance the car out some but it was still just a touch pushy. The car pulled in with a 63.341 (see, I told you I was consistent!) clean but it wasn't enough to hold me in third place. Shawn in a Hype Argh came in just a little faster on his third run with a 63.196 and kicked me back to fourth.
Dave's run #3: Dave confirmed that the car was getting closer to where it needed to be but it still required making the front do all the work and it was most noticeable in the slaloms. We upped the rear rebound another quarter turn and bled the fronts down to 31 PSI and the rears stabilized at 33 PSI and didn't climb from there. This run came in with a 63.367.
Run #4: The final run, with the changes we had made before this run, the goal was to go out and get a solid fast time. Neal Tovsen drove the car the day before and ran a pretty solid time that wasn't far off his own time so I know the car can be faster. While in the line waiting to go I recapped the places where I felt like I was losing time and set forth to correct those issues. About the time I got done with the second slalom the fronts were getting hot again and I entered the fast left hand sweeper just a touch fast, started to push and mid corner lifted. Well, in hindsight I should have just stayed in the throttle because when I lifted the fronts grabbed traction and I lunched the apex cone. I pulled into the finish with a 62.555 but had managed to find another cone somewhere on course. The run went down as a 66.555 with those two cones.
Dave's run #4: Dave's final run ran with the same settings that I had on my final run and once again, he confirmed that the car felt better but just simply had too much rear grip. He hypothesized that the torque arm rear setup was working a touch too well. He suggested running some stiffer springs in the rear to help compensate and was pretty adamant about not adding any more bar (I do have a Strano/Hellwigg 25mm rear adjustable bar I could throw on) but spring instead. The car as a whole could use some stiffer spring rates so I will be looking into that for next season. This run he came in with a 63.498 and didn't improve. He would finish fifth and I finished fourth of 6 in STX.
Recap: At the test'n'tune I moved the front swaybar to the stiffest setting which I think contributed to the rather planted ass end feel that the car had. Neal managed to ring in a pretty good time in my car compared to his own and hypothesized the car was only a second and change off pace but the car was balanced. He also had some encouraging words about the cars in STU.
At the actual event, the car was pushy, and pushy in places it wasn't pushy at the test'n'tune. The overal conditions were similar both days, hot, humid and in general not a very nice day to autocross. Dave and I finished fifth and fourth (respectively) in STX and nineteenth and eighteenth overall of 74. Neal Tovsen took first in PAX and first in class. The split between myself and Neal was a little over 3 seconds.
What's next? What's next is Nationals and for Nationals I have moved the front bar back to the middle position. The front bar at full stiff did not make the tires work any better, did not decrease body roll significantly and added a ton of push to the car. I would rather work around the throttle oversteer (which probably wont be present at Nationals, who knows since the car itself isn't consistent between events) than deal with terminal push. Loose is faster than push, supposedly. I'm not changing anything else before Nationals. I'm supposed to be scheduled for the Evo T'n'T on Sunday so hopefully I can get some valuable seat time as well as a little bit of instruction if any of those guys are willing to help me out!
For next year, I plan on investigating stiffer springs, not just stiffer in the rear, but stiffer all around. The car on 265/40/18 RS3's has plenty of body roll. I'm thinking about 525 front, and 250 or 275 rear and I hope that the valving currently on the GC valved dampers can handle those spring rates. I also hope those spring rates strike a reasonable compromise between ride comfort and flatter cornering. Next year the plan is wheels/tires (again...) for STU, diff, harness bar and harnesses and if the budget permits, seats. Basically in that order. I don't want to add power to the car just yet. I want power to basically be the last thing the car gets and I'm willing to bet that if I get the diff in next year it will be a good year. The wheels will be the 18x10.5 Enkei PF01 (can't mess with a good looking car! :P) that Sam sells that fit square. I just hope they fit well enough that I can drive to and from the events with them on. The tires will probably be 285 wide RS3's unless a better tire is found between now and then. The ZII's don't have a 285/35/18 tire and only a 285/30/18 which is TOO SHORT. Heck, a 285/35/18 is still too short but it's at least workable. The diff is still a Torsen T2R as planned.
Videos: (Sorry Dave, I forgot to tell you how to operate the cell phone for video =\)
Run #1:
Run #2:
Run #3:
Run #4:
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