Streets of Willow

[TigerBlue]

LASAAC hosted a great Open Track event at the Streets 28-29 May2011. I attended with TigerBlue along with Steven Alcala with his Sebring Alpine. The 3 run groups were not overcrowded and there were 6 track sessions available both days. 20 and 25 minute sessions on the sched.

The track layout we ran was clockwise and minus the "Bowl" for safety sake.

http://www.willowspringsraceway.com/trackinformation/StreetLg.htm

Tiger ran flawlessly which is a good thing. I had not run the "Streets" in awhile and there were some slight changes in the south bound downhill not quite straight leading to the left 90 that takes you back towards the skid pad (last turn on to the main straight). Fun to drive and a challenge to make clean transitions as the turns come at you one after another.

The last session was great fun as I was playing with a couple other guys. A much modified ex Bondurant school car and that Ford SVT truck (in the picture below hounding a Cobra Rep). We traded the lead on front straight (not racing but the leader pulling right and slowing) and chased the new leader with this odd trio of vehicles. Met them that evening at the LASAAC BBQ and agreed that was lots more fun than just lapping by yourself.

Unfortunately I found my front tires toasted and that meant I was done and had to skip the track sessions on Sunday and go home early.

Pictures from Saturday below. Someone I talked to told me had some shot of TigerBlue so if they show up in my E-mail I will post them too.

The drive home to San Clemente Sunday early was easy. Got to buy some tires though.

Rick

 

[michael-king]

Rick,

As always thanks for the track pics, and looking forward to seeing pics of tiger blue doing its thing. I really like how the Sebring Pine is showing the way to the stangs etc... bet they got a suprise watching steve blowing past them on the straights... hey its a still picture i can read it that way!

 

[TigerBlue]

More from the "Streets"

I have a Racelogic Performance Box made by Vbox.

The VBOX has performance measuring functions and when set correctly can provide lap times after a session and all the time it is logging the 3D position on Earth of itself and the car carrying it. Every tenth of a second it records LAT, LONG and elevation from the GPS receiver.

Attached is a trace of one of TigerBlue's fastest laps last Saturday, a 1 + 21.5 That time was late in the second session and I never got under 1 + 23 in the afternoon. Why? density altitude was higher - less HP and the tires were going away? At the time I felt I was faster but sliding more and just over-driving the car.

The outline of the "Streets" was manually traced from Google Earth in 2008. Where it appears that I took a shortcut southbound is where the track had been altered since 2008.

Max speed each lap was just over 90 at the first turn. The lap below had a max speed just under 90. Min speed was about 35 on the last turn. The "skidpad" has no camber to help turn the car. Third Gear only except for one shift up before the first turn with a couple seconds accelerating through before the downshift approaching turn 2. I was planning to try second gear in the 180 degree skid pad turn on Sunday but did not get a chance.

Rick

 

[michael-king]

Rick,

I kind of like the shortcut lap!

Its interesting to see your lines through the double apex turns and the line you take through the sweepers at the top where you stay left to get ready for the RH hairpin.

From the pics looks to be fair bit elevation, that with all the double apex corners im sure its quite a fun but techincal lap. How does the tiger go with the long radius corners.. for a short wheelbase that would make it a bit tricky as the loads build up towards the end especially if you then transition to hit another apex.

 

[TigerBlue]

Answer for the King

Michael

Hard to answer your questions but I can post a couple more images from Saturday to try with words and pictures. Let's call that Turn the North Turn (NT).

My approach to the NT was not following the cars ahead which were on a line a car width or so off the left edge of the track. I found I could floor it and hold the edge of the track. I seemed to close the gaps ahead doing this and be in position to brake and turn in for the NT. Note the positive, left turn G approaching + 0.9 on the chart...then the transition to - 0.9 peak on the right turn North Turn.

You asked about transitions? The blue line on the chart is braking lower half and acceleration upper half of chart. This is the fore and aft component of what is called the friction circle. The tires can only do so much. Max lateral G with 0 longitudinal acceleration and vice versa. Most of the time the car is doing both. Early accel is important to straight line speed.

The NT is without any camber to help turning, It is a level short straight providing the option of a shorter course and the double use as a continuation of a straight as well as a turn precludes any helpful banking.

At about the 9.5 second mark on the chart, TigerBlue is getting the throttle opened and accelerating from 45 to 75 southbound.

As far as the handling of TigerBlue? In the long turns a little play with the throttle helps. Going wide? lift momentarily and then ease the gas on works for me. The short wheelbase makes left right transitions easy. Maybe too easy as it can easily rotate more than you wanted. Lots of fun.

Keep in mind that I am an amateur at this and not even an amateur racer. I have a lot of laps of open track events though.

Rick