Tuesday, May 24, 2011

[5/22/2011] SRTA #1 (DDT)

Event: Sigma Racing Time Attack #1
Track: Mosport DDT (CCW w/ 2 kinks), Bowmanville
Weather Conditions: 15°C~23°C, Overcast with light drizzle

The 2011 Time Attack season has begun! SRTA marks my foray into the world of competitive grassroots motorsports. Today was the day to see if all the work I've done since the beginning of April had paid off. The day started bright and early, waking up at 6:00AM to head out to Mosport. I cruised up with my buddies James and Alan and we got there at 8:30AM. I had a pit crew that did an extraordinary job of helping me setup and tune my suspension settings throughout the day. Huge thanks to Francis, Tang, and his friend Andrew, who showed up to help because the engine on his Ford Escort blew up and he couldn't run his GT Sprint race.

Speaking with Andrew, he recommended that I shoot for a hot tire pressure of 37 psi. With that in mind, we began the test & tune phase of the day. The Official Time Attack (OTA) was scheduled to start at 3:00PM so that meant we had a solid ~5 hours of test & tune time. I also knew from other competitive (non-racing) events that I had to pace myself throughout the day and eat healthy in order to stay focused before the real event.

Test & Tune

Run 1 - Dampers +8/+8 Best Time: 1:15.67
I started off with the +8/+8 damper settings I used at Cayuga. Cold tire pressure was 33 psi all around. I did about 5-6 laps to get heat into the tires and immediately exited the track without a cooldown so that Tang and Andrew could measure my hot tire pressure and temperatures. Hot pressures were 37 psi all around except for RH which was 38 psi (CCW track). Tire temps were (outside to inside) 44/46/48°C (LF), 58,56,54°C (RF), 37/39/41°C (LR/RR). +2°C difference in temps seemed like a pretty small spread to me, and Andrew agreed it was rare to get the tire temps even all around in real world testing. (I later found out from Peter Hanson that the ideal temperatures for my RA-1’s are in the >70°C range, but that’s from inside of the tire). Maybe I could use an extra -0.5 camber up front but it's probably not worth the effort right now. I also wasn't focusing too much on my line yet - I just wanted to get the settings right.

Run 2 - Dampers +10/+10 Best Time: 1:12.86
Bumped the dampers up to +10/+10. We noticed that on the track, the front end was plowing under braking, and the car was quite bouncy/underdamped from all the elevation changes. Tire pressures went up a bit to 41 in the fronts, and 38 in the rears, so we bled them back down to 37 psi afterwards. Temperatures went up too, but the spread stayed +2°C from outside to inside; 52/54/56°C (LF), 58/62/61°C (RF). I decided to take a short break for lunch and then crank the dampers to +15/+15 afterwards.

Run 3 - Dampers +15/+15 Best Time: 1:12.11
This setting felt better and more composed. Less body roll and more confidence through the kink in the fast straight. I was beginning to be convinced that stiffer on these coilovers always meant better. I continued to shave my time down by a couple tenths but could not break into the 1:11's. Alan in his 305 rwhp RX-7 did a 1:10.16 and James in his EK Civic had a 1:11.60. I was eager to break into the 1:11's because I knew my car was capable. It was time to stop worrying so much about the suspension and time to start focusing on the time attack!

Run 4 - Dampers +20/+20 Best Time: 1:11.37
By this point I was running a little low on gas, around 1/3 tank remaining. No problem because I brought an extra 20L of Ultra 94 in my gerry can right? Wrong! Note to self: label your gerry can. Alan brought the exact same one, and since we pitted beside each other, he used up all my Ultra 94 by accident LOL!! Unfortunately his was filled with 91 and some mix for his water injection system so I didn't want to risk feeding that to my suby. On the bright side - Andrew and Tang both gave me valuable feedback in their runs with me on my line. I also noticed a lot of areas for improvement as well. Dive bombing and trail braking into T2 while down shifting into 2nd gear gave me extra torque for T3 and T4 and allowed me to carry WAY more speed into this section of the track. Power could be applied sooner after T6 and I needed to desperately stop cutting the curb so hard at T8 because it upset the suspension too much. T9 I needed to miss the first apex and clip the 2nd while staying more to the right of the track on exit. At this point I was down to a little over 1/4 tank. I didn't want to risk running out of fuel for the OTA. It was starting to rain at this point... and all the drivers agreed to start the OTA early.

Official Time Attack

SRTA broke drivers down into heats of 4, starting with the fastest drivers first. I was in the 2nd heat. As I drove through the skid pad to be staged for my OTA I heard the dreaded "beep beep beep!" that I heard back at Cayuga. My GoPro batteries were dead!! So ironic... just before the OTA. But I was prepared this time! I quickly did a U-turn and drove back to the pits to grab a new battery. Considering my times all day, anything in the 1:12's would be acceptable "under pressure", and anything under that ideal :)

Here’s my OTA run “home video style” from my friends' point of view:

Here’s my OTA run from inside the car:

My best time was the 1st hot lap of 1:11.71. Overall I placed 6th in Group B of 24 participants in total. I’m really happy that I was able to put down a time that was consistent during test & tune and that it was fairly close to my daily record. Post-OTA tire data was 34 psi/50C fronts, 35 psi/36C rears. Next time I might have to set my cold pressures a little higher before OTA.

Improvement Points

Trailing Arm Bushings: I experienced a lot of driveline pogo during my runs, regardless of the damper settings. Passengers said the same thing. Normally I can live with it for day to day driving, but at the track it’s killing me. The power delivery from the apex through the exit is so chunky that it’s upsetting the suspension. I’m assuming that the culprits are my tailing arm bushings – which happen to be made from gummy bears on our cars. It’s one of the few bushings that I haven’t changed out – but now I plan on changing it out ASAP. I originally intended on doing a Cayuga track day on May 28th but will be cancelling my plans for that and directing those funds towards stiffer trailing arm bushings instead.

Left Foot Braking: It’s time for me to pick up left foot braking, or at least start experimenting with it. I don’t know if you guys can see it in the videos but I’m actually fighting to turn the car through every corner. My suby pushes like a tank!! I really want a bit more rotation out of the car, but I don’t want to go the easy route and drop a load of cash on something like swaybars yet. I want to see if a little bit of left foot braking can get the car to turn-in better on the turns that don’t require any downshifting.

Misc. Consumables: I also noticed my front pads are being worn down a lot quicker than last year. It could be because of the DBA slotted rotors and/or that I’m pushing my car much harder this year. My RA-1’s are starting to look worn too… they were manufactured in 2007 and I bought them used for $200. This will be my 3rd track season on them. I gotta tuck some money away for the consumables too, just in case.

Bonus Videos!
Now, we can’t be so serious about lap times all day long! Here are some bonus videos for your enjoyment ;)