Track Day Report - Gainesville Test Course - 01/08/11

What a day! After some mishaps early on in the morning, I have gathered some good results.  I got there late, at around 9:00am.  Fortunately they hadn't started the drivers meeting or anything yet.


Conditions: 52 degrees at 10am, 65 degrees at 12:30pm.

• Changes from previous event:
• Tires a bit more worn
• Hi-Kick Racing design front splitter and rear spoiler (Both 7")
• Airtab® Vortex Generators
• Passenger seat was still removed

Session 1

Spoiler at the third highest setting and tire pressures at my 36f and 31r, I went out.  Two bad things happened here.  I a lot of oversteer due to lack of rear downforce, and I was putting my brakes through hell.  Months before, I had replaced my Hawk Black pads to Axxis ULT pads, which were rated "track worthy."  The brakes got spongy after a lap or two, and I could smell fumes from outside the car.  I did a few more laps and I pit back in.


Fastest Time: No laptimes were recorded because I messed up the settings on my laptimer.


I went home and changed the pads back to my worn down Hawk Blacks in a hurry. They had about 20% of life left in them.  Took me an hour to drive, change, and drive back.  I arrived at noon, and asked Grant to drive my car.

Session 2

I adjusted the spoiler to its second highest setting.  No other changes were made.  I went right back out and did a few more laps than the last session.  Handling balance was a bit better, but I was still loose around transitions and kept scrubbing off speed with the end kicking out.  Two problematic areas were the transition between turns 2 and 3, corner exit at turn 4+5, and after the second apex on the chicane at turn 7.  I decided to pit in after a short cool-down run before I boiled my brake fluid.


Fastest Time: 1:02.8
Average Time: 1:03.3

Session 3 - Vortex Generators (Airtabs®) 

I taped four vortex generators in the middle of the rear edge of my roof.  Both had the same laptimes.  Its hard to quantify the exact effect but comparing the best sector times between the VG run and the non-VG run (session 2) in the constant radius turns (turns 2 and 3), the VG installed car seems have slightly higher average lateral acceleration.  My driving in this session with the VGs is also much more consistent.  Furthermore, the car felt more stable.  Objectively speaking, it could be just because I was more used to the car, but I really think it was the VGs that made the difference.  I didn't adjust my driving very much in this run and I drove much cleaner.  I will make a separate post about my experiences with the Airtab® vortex generators.


Fastest Time: 1:02.8
Average Time: 1:03

Grant's run

Grant driving my car

Because I missed out on a lot of track time changing my brakes, I asked Grant to do a short stint.  I dropped the rear tire pressures about 1.5 lbs.  He says he can go faster with a few more laps and even faster with a better driving position.  Grant barely fits in my car.
Benchmark time was 0.4 seconds faster today than his last record of 1:01.8.  His time was 1:01.46

Session 4

With VGs installed, spoiler at second highest setting (man, I need to number the positions), and rear pressures the same as when grant drove the car, I did a 1:02.1. Woohoo! Personal record.  Some of its due to better driving, some of it is due to lower temperatures (should be about 5 degrees lower than my previous record) and some of it is due to the aero mods I put on my car.  The tires have been aging each event, but I guess the changes to the car and driving made up for it.

Driving Notes

Even if I dive-bomb into the chicanes, turning in early and hitting the initial right-side apex allows me to bleed off speed and properly later-apex the left side apex.  Mimicking grant's driving, I accelerated off of that apex into turn 9, but I have to make sure I am positioned correctly on the far left side of the track in order to make it into turn 9 without coming out too wide.  Smooth inputs with steering and throttle are critical in order to not oversteer in turn 9 entry.  This is even more applicable because my car is more neutral.


With aero mods, I can get on the gas way earlier than usual; carefully dialing in throttle allows very good acceleration off of turn 9. Trail-braking into turn 1 and 4 works very well also.

Conclusions

I can say with good definiteness that the front and rear aero mods and the Airtabs® had a net positive effect on the performance of the car.  Top speed of today was 1.5 miles higher than my past top speed, even with a lot of fuel in the car.  Even if I account for the cooler temperatures, this is pretty good.  This means that putting down more power with the increased aerodynamic grip on the exit of turn 9 overcame the drag penalties of my splitter. Vmax: 75mph!

Some more pictures from the event. Pictures seem to be of all Mazdas today!

By the way, I attended the 24 hours of Lemons in PBIR as a crew member. I'm still working on the report; stay tuned!