41st Track Report at California Speedway Infield
Oct 21/22 2006 with Speedventures.

The Track Day.

Finally, we are back to California Speedway Infield again. This is the second time that Speedventures has organized the same configuration since April 2006. I was at the April event earlier this year and if you haven't read about my minute gripe about being denied a 3rd place trophy, please go here.

The event was sold out according to Aaron (organizer/owner/planner) of Speedventures. Each run group has about 18 ~20 cars due to the smaller track. As before, this event ran over 2 days with 4 run groups per day. Each session runs for the usual 25 to 30 mins. I signed up for the advanced group with open passing and race-like conditions.

The time trial/time attack event is usually on Sunday. So for those preparing for that segment of the event, we have the entire Saturday and two morning sessions on Sunday to practice. The pre-grid for the time trial/time attack event is simple: line up cars by their BL from the morning sessions on Sunday and send the cars out for 4 laps. The 4 laps include: warm up, 2 hot laps and cool down.

Just before the time trial, I had to work on one of the the brake duct backing plates. It was grinding against rear of the rotor. No big deal really when you have all the right tools.

So did I win back my trophy this time? Well, not quite. But I did improve more than a second since April 2006. You can read more about what happened below.

Overall, SV pulled another great event. We were always on schedule for both days. Free flowing bottled water and pizza as always. Friendly crowd. Did I mention my wife accompanied me for both days? :-)

New best lap!

Perhaps the most exciting thing about this weekend is that I met my goal of breaking under 1:19. The last trip in April, I did a BL of 1:19.532 and this time I clocked a 1:18.063. That is an improvement of 1.469s!!

What did I do to get around the track faster? The red line below represents the 1:18 lap and the green line represents the 1:19 lap.

I was able to carry more speed through the bus stop (Segements 8 through 10). Who on earth needs to brake through 9?? LoL! Not to mention I was on the gas earlier coming out of Turn 12 as well. The plots appear a little fuzzy because these are wheel speeds not GPS_MPH.

** Mike @ Technik Engineering mentioned that my improved BL may be due to the installation of a race seat and a 6-pt belt system. Thanks for pointing that out. It is true that a race bucket will keep me in place and focus instead of fighting g-forces. The car also has a 80-lb roll bar added. Other than these two modifications, no other mods are done to the engine or suspension.

The verdict? I have very happy with my new BL. Though my TL shows that I can improve another second more. My improvement has to do with my better driving skills and the NT-01 tires, which I shall talk about in the following segment.

Nitto NT01 235/40/17 (Part 2)

This is my continuation of reviewing the Nitto NT01s. I first fully pushed the NT01s at Buttonwillow on Oct 15, 2006. And this is my second opportunity.

The NT01s did very well for both days, with plenty of life left. John from Nitto Tires said the tires will just get stickier and I have to agree with him.

The tires didn't take long to warm up either. The Infield is a very short track. All it took was half of the warm-up lap and the tires are good to go. This is based on my Time Attack session experience.

The undeniable fact is I did improve by nearly 1.5s and these tires were mounted BRAND NEW and FRESH off the shelves.

Below is an informal comparison of the lateral Gs generated when using Toyo RA-1 and Nitto NT01. Note this is not the lateral G as measured on the tire surface! This is the lateral Gs as experienced by the car's C.G. Weather for both days are similar.

Click image for to enlarge.

What are we looking at here? The red line represents zero lateral Gs and the blue and yellow plots represent the corresponding tires. In mathematical real analysis, we can express the "closeness" of two functions under the Lp spaces. The Lp spaces are a class of Banach spaces of functions whose norms are defined as integrals. The Lp of a function is:

Ok, hold on there. What does this mean?The idea is very simple. When we compare two plots (or functions), we take the area under each plot and compare them. Intuition will tell us that if both plots are about the same, then the difference is zero or near zero. We all have done the integration in our Calculus 101. But is the function in our comparison an intergrable function? It sure looks like it but remember our datalogging device actually samples data at a fix rate. So as it may appears to be a continious plot, it is actually joined by little segments at fixed intervals. So another approach is to look at the sequence of data generated by both plots and analyze the norms under normed linear spaces. For the nerds out there, this means the integral operator becomes a summation operator.All these jargons must be causing a headache by now. So instead of geeking out everyone, the one way to see if Nitto NT01 actually allows me to push more lateral G than Toyo RA-1 is to study the plots again and ask this question:Is the blue plot almost always above the yellow plot when G > 0 and always below when G<0?It is evident that I pushed the car more for first half of the track. The blue plot shows that. The answer to this question is a good yes but there are other observations.

Time trial = time attack?

What's the difference between the two? Someone updated Wikipedia saying that both are the same. The objective is the same which involves competing in some level or class and driving a vehicle around a lap as fast as you can. It is not what we deem as wheel-to-wheel racing because we are not rubbing shoulders on the track or stealing apexes. It is however still considered a highly competitive event. Redline Track Events run their own time attack and so does Super Street magazine.

So as you may recalled, I started in NASA Time Trial recently. As it turns out, there are two different ways of classification: by car and by driver. Aaron promptly explained the differences:

• NASA TT is by driver. Meaning that the organization tries to equalize the cars between the different drivers as much as possible and the competition is to see who is a better driver on the track.
• By car means to initially place the car in a larger set of classification and then let the tuners dish the cars on the track. This compeition is to see who has a better car on the track.

Hrm...still can't see the difference? The original time attack from Japan is car based rather than driver based. Car based classification means tuners have to modify the cars to get the best time around the lap NOT upgrade the driver. Although the driver's skills is part of the equation of a fast lap as well. But we all know that there are two ways to clock up a fast lap around the track. That is to either upgrade the driver or upgrade the car. The former is generally more intangible and the latter, frankly to most folks, is more exciting.

For simplicity, maybe we can call the driver based as Time Trial and car based as Time Attack. Speedventures runs a Time Attack in this sense and NASA runs a Time Trial. SV classifies the cars as shown:

I ran in Turbo Street on Sunday.

So what's rather unfair about a Time Attack? Well, if someone brings a more expensive and faster car and compete in your category, then you can kiss that trophy goodbye. Here's an example. Turbo Street means any factory turbo cars are included. WRX, Evo etc. And yes means even a Porsche GT car. And true enough, on Sunday, a Porsche GT2 did compete in the class as me. So am I even competitive in this class? Unforunately no. That GT2 clocked up a 1:11.XXX and my best for the time attack was 1:18.177. So naturally I was knocked out of a position.

The other flaw in this system is that you could look around the garage and see if anyone is competing in a certain category. As I recall, no one competed in Turbo Race or maybe one did. If I had signed up for that I may have a position.

But the more important thing is to have fun at the end of the day regardless. :-)

The verdict? I was a little disappointed for not recovering the trophy I lost in April but the more important thing is that I clocked up a better lap time since then. That, IMO, is the true spirit of a time trial/time attack event. You compete against yourself.