Sunday, June 22, 2008

Super Taikyu Round 3 - Fuji Speedway

Onboard video (Part 1):

Onboard video (Part 2):

Both of these videos are available in high-quality (perfect for full screen viewing) at these links:

Super Taikyu Fuji Speedway Nissan Fairlady Z race onboard view (Part 1)

Super Taikyu Fuji Speedway Nissan Fairlady Z race onboard view (Part 2)

These videos only show the start and the 5 passes.

Igor Sushko, Masaaki Nagashima, and Kazuomi Komatsu on the podium at Fuji

Last weekend was the third round of Super Taikyu at Fuji Speedway. It's a rather different setting compared to last race's Sendai Hiland track, which is a decades-old track in the middle of a mountain range. As a Formula-One host track, Fuji Speedway is all that a driver can want - the smoothest surface, good track width, challenging configuration, and safe run-offs. The garage facilities are also more than twice the size of any other track, allotting each team plenty of room with private offices, lots of TV monitors, and even a private-use restroom. Shower rooms are also scattered around every 100 meters through the pits.

Due to the proximity of the track to my house in Yokohama (only about an hour), I arrived on Friday morning and got on with the car setup. The car was pretty good from the get-go as it remained unchanged from the Hiland race, but I knew that we would have to minimize rear drag to take advantage of Fuji's long straights.

Between the three test sessions on Friday, I was able to come up with a pretty good setup. But for the Saturday qualifying, I wanted to go a bit further, which meant lowering the car 2mm F/R and lowering the rear wing even more.
This backfired however, with the car losing its good over-steering characteristics. I was really surprised, but there could be no mistake that the lowered rear-wing was actually generating more downforce/drag. 100R, a very long right-hander in 4th gear around 140-160km/h made me struggle with an impossible understeer (too much rear-traction and not enough front traction). When the rear generates a lot of downforce compared to the front, all that force actually pushes downward on the rear so much that it unloads the front a bit, making the balance problem even more severe. A bare 2mm lowering of the ride height in the front and rear also had very bad side-effects. The suspension was no longer able to function properly with a lot of bouncing and severe understeer in slow corners.
Some of our race queens

The reason that one can make both suspension and aerodynamic adjustments (to an extent of course) and still distinguish the cause-and-effect of each is actually pretty simple - downforce only comes into play at high speeds, and is rather significant in the balance of the car, but in lower speeds (2nd gear/3 gear corners) the effect of downforce is nearly null, so at lower speeds, one can safely attribute the balance of the car to the suspension.

Of course, this is not the case in formula cars and prototypes, as they generate significantly more downforce (even at low speeds) and are much more sensitive to all adjustments.

So, I ended up butching the qualifying with a time of 1:54.2, around 1.5 seconds slower than the top car in the class. I made four attack laps in hopes of getting some kind of miracle time despite the poor balance of the car, but all four were within 0.2 seconds of the above top time, so it was pretty clear this was near the limit for this setup.

I looked over the data and saw that we lost over 6 km/h of speed on the straights, and combined with my feeling of strong rear downforce and the front lifting up, there could be no mistake that the lowered rear wing was not working as intended.
Fuji Speedway Track Map

I used our third driver's qualifying session as a test since the C-driver only needs to pass a standard lap time and the actual time does not count for position, not that I could do any worse than I had already done. So we raised the car back up 2mm front/rear and tried 2 wing configurations - just raising the front of the wing which makes the distance the air travels above the plane and below the plane more equal, and also reverting to Friday's wing configuration.

Sure enough even on old tires and a full tank of gas, Komatsu-san easily drove in the mid-1:53s. The data also showed a regaining of 7km/h with the new adjustment, while the Friday's configuration did not show that gain in speed.

Although our qualifying was horrible, we finally found the right setup for Fuji.

Igor Sushko before the race at Fuji Speedway

We decided that I will be the starting driver, followed by Nagashima-san, and Komatsu-san the anchor.

With an 8th place start, I had to make up lots of positions for us to get on the podium again.
Start of the Super Taikyu race at Fuji Speedway

I did. My stint was 42 laps, and I passed 5 cars to pit in 3rd place.

After the pass of the #113 Nissan Fairlady Z for 3rd place

After my stint, Nagashima-san and Komatsu-san maintained the position and we finished the 4-hour race in 3rd place.

The Super Taikyu podium for #15 Nissan Fairlady Z

Next race is this coming weekend at Fuji in Formula Renault.
The next Super Taikyu race is on 7/20 in Hokkaido, the northern-most island, and is a 24-hour endurance race.

Visit the photo gallery for: 2008 Super Taikyu Rd.3 at Fuji Speedway (#15 Okabe Jidosha Dixcel Nissan Fairlady Z)