39th Track Report at Streets of Willow Springs
Sept 8 2006 with SpeedVentures

Configuration
CW
Mean Ambient Temp
33C
Mean Track Temp
43C
Track Hours
1.5hrs
Track Miles
45
Best Lap
1:32.781 (TL: 1:30.776)
Weight (no driver) to Wheel Power Ratio
3300lbs(est)/240whp or 13.75

The Track Day.

What? Another track event in less than a week?

Well, Aaron of SV offers a bloody good deal that is too hard to resist. For those who signed up for the last event, Sept 2 2006, we are given a $60 discount if we attend this event at Streets of Willow Springs. This means that we will get to run the Streets for $80. That is a deal in my books. Since I haven't driven at the Streets for a while, why not sign up.

The last time I was out here at the Streets was in December 2002. Yes, you heard me. That's more than 3 years ago. Back then I hated the Streets because it's a relatively short track and it wasn't as exciting. From 2003 through yesterday I have never set a foot in the Streets.

Streets of Willow Springs is the other track located in the Willow Springs International Raceway facility. If you look at the map below you will see the relative size comparison between the Streets and the Big Track. While the Big Track has generally been known as the track "That Requires BALLS", the Streets has been crowned as the track "That Requires Car Control Skills".

The Streets is a low-speed track. My average speed around the track is about 60mph. Yep you heard it right. It's only 60mph on average. To compare, my average speed at the Big Track is about 87mph and at Buttonwillow 13 CW about 75mph. You use mostly 2nd, 3rd gears at the Streets. One might pop into the 4th gear but not for long. To me, the Streets is like an outdoor kart track but designed for cars. You can slide around almost every corner. You hardly have time to check your gauges and you're always tackling corners.

The rather ballsy and perhaps the easiest turn of the Streets is The Bowl (refer to the map above). It's a 20 deg banking that sweeps about half a circle. You think you need to brake hard before tackling The Bowl but all you need is just lightly tap on the brakes and, swoosh, you have a NASCAR moment for about 5 seconds.

I must admit I had a lot of fun at the Streets. This track reminded me of the California Speedway Infield track, where the median lap time is about 1:20. Here at the Streets, the median is about 1:35. It's a short track with a lot of attitude and IMO it is one of the the best places for learning how to control your car. This is the place to throw your car around and learn new tricks on how to control it. Now I see why WSIR has two tracks with such an extreme driving experiences.

However, fun comes with a price. The Streets is hard on the engine and the tires. Most of the time, you're driving in the higher RPMs. Just when you upshift, you will have to downshift again. Oil and coolant temperatures will be a little higher than normal. So be warned about that. If I were to return to the Streets, I would drive with street tires and not R-comps (too expensive!).

I strongly recommend this track to track drivers from any levels. It maybe a short track but it's a memorable track.

Things to test out and report from this event:

  • Power Steering Reservoir Overflow Bottle.
  • Number of Gear Shifts Per Lap.

 

Power Steering Reservoir Overflow Bottle.

This overflow bottle idea came from two folks: Mike @ Technik Engineering and Scott from SCTS Racing. A long time ago, Mike saw that my power steering reservoir was a bit messy and he asked "Can you install an overflow bottle?". That got me thinking but I never really look into it. The partial idea also came from Scott. He had a coolant overflow bottle in his race car. It was a cheap water bottle with some tubings.

Out of boredom during the in-between-track-events period, I decided to take on this project. I searched around the house for a empty bottle, fittings and tubings. And I finally put something together.

The power steering reservior has a small hole on the cap. A small plastic barb fitting will fit right in snugly. Some modifications maybe needed. Then I use 2-ft of vacuum hose (1/8" ID)to route the fluid to the plastic bottle. You can locate the overflow bottle any where you want but make sure it's below the reservior. Common sense.

So does it work? Well, see the picture below and judge for yourself. The plastic bottle slightly deformed but it does its job well. I would recommend using a non-plastic bottle, eg glass or aluminium can or something.

The verdict? One of the best modifications ever. Now, I don't have to deal with messy underhood fluids. Yucky days are over.

 

Number of Gear Shifts Per Lap.

I decided to study something a little different for this report. As mentioned, I realized that the Streets is a lot harder on the car, thus higher oil, coolant and transmission temp. Below are three plots from my G2x unit. Each plot presents the gears used for one lap at each track. The G2x unit allows me to program a gear indicator function. It's a simple engine RPM over MPH function. Nothing too fancy. As you can see the data are a bit noisy (due to a direct wheel speed sensor input rather than GPS MPH input) but it doesn't mean that the gear wasn't engaged properly. If you observe carefully, there are actually "square" trends in the plots, which a gear change plot should look like.

From the Streets

From Buttonwillow 13 CW

From Willow Springs Big track

Based on the plots, I count the number of gear shiftings during one typical lap at each track and tabulate the following:

Track
No. of Gear Shifts
Lap time
Seconds
Seconds/Gear Shift
Streets
12
1:32
92
7.667
Buttonwillow 13 CW
13
2.10
130
10.000
Willow Springs Big Track
7
1:40
100
14.286

From here, we see that it takes an average of 7.6s for each gear shift at the Streets. This means you use each gear for about 7.6s before changing it. This is is almost half as long when driving at Willow Springs Big Track. The Streets is the one track that I witnessed a higher running oil/coolant/transmission temperature as well. As you can see, Buttonwillow hangs in between.

The verdict? An interesting perspective to track driving and how your car performs on the track. Perhaps it's just my car and my setup, but my intuition tells me the more gear shifts you have per second (or the shorter time between gear shifts) on the track, the more stress you're putting on your engine. Makes sense, doesn't it?