Monday, May 28, 2012

Saturday, May 26, 2012

State of the rubber

It looks like the Dunlop D03Gs (H1 compound) are well and truly end of life, the tread is now heavily uneven left and right. These have done 9 track days - 7 at Winton, 1 at Wakefield and 1 at Sandown.


The Hankook Z221s (C30 compound) appear to have had minimal wear after 5 track days - 2 at Winton, 2 at Sandown and 1 at Phillip Island.


Friday, May 25, 2012

[Video] MX-5 with a broken exhaust

Ever wondered what an MX-5 sounds like with virtually no exhaust pipe/muffler? Click Play to watch the Noisy Ninja tackle the S at Winton.

Wednesday, May 23, 2012

Exe Crew Track Day - Winton Raceway 19th May 2012

Today was the first of a two day track event that Exe Crew held at Winton on the weekend of the 19th and 20th of May 2012. It was a first time that we have run a two day event.


No PB today however, close but no cigar. The difference in setup this day compared to the last time I was at Winton (Nov 2011) was that I had to use my old Dunlop D03Gs on the front as the Yokohama A050s had worn out on the outer edges.

Session 1
2:01.7860 1:44.6500 1:43.0140 1:42.3320 1:50.1070 1:43.3210 1:42.7070

Session 2
2:09.1600 1:42.5830 1:42.8610 1:42.2510 1:42.3910 1:41.9820 1:41.9680

Session 3
1:53.6150 1:42.4740 1:42.3070 1:41.8320 1:42.0760 1:43.5040 1:41.9130 1:42.2330

Session 4
1:53.6340 1:42.8250 1:41.8550 1:42.0710 1:41.6970 1:42.3530 1:41.8100

Session 5
1:50.2650 1:44.1950 1:42.9300 1:48.9570 1:44.4320 1:45.2330 1:43.1990

Final session (3 laps per car)
1:47.0430 1:42.4450 1:43.3520

In sessions 1-4, I was trying out higher tyre pressures - 38 PSI front and 35 PSI rear. I had read in the Hankook motorsport tyre catalogue that 40 PSI hot was a good starting point for their tyres. Up till now, I had always run semis on lower pressures around the 30 PSI mark hot as I thought that was the way to go. What I found with the higher pressures though was that steering feel was sharper, although the car was sliding more. The front tyres were also understeering and hopping during tight corners like the hairpins, but this might be due to the old tyres. I was fighting to balance the throttle application so that the car wouldn't understeer. The slipperiness of the rear also made me a little hesitant to get on the throttle earlier but once again there was a battle to apply enough throttle so that the car would grip out of corners and not understeer. Despite all these issues, I managed to record down a few 1m:41s so I was happy that I could do it consistently. I'd like to give it another go with brand new tyres at the front. In session 1 I also took Vivski out for a ride and I think he approved of my driving.

My theoretical best lap is a 1m:40.57s, so it's a matter of keeping it together and linking up all the fast sectors. This theoretical best lap is made up of the following sector times and I have noted in brackets the actual lap they came from.


Sector 1: 17.65s (Session 3, lap 7: 1m:41.91s)
Sector 2: 21.92s (Session 3, lap 4: 1m:41.83s)
Sector 3: 43.53s (Session 2, lap 4: 1m:42.25s)
Sector 4: 17.47s (Session 4, lap 7: 1m:41.81s)

The graph below, we can see the fastest lap of the day (1m:41.69s) as the brighter yellow line. The lighter line is the optimal lap (1m:40.57s). So, I need to:
- go faster through turn 1.
- go faster through the sweeper.
- brake a little earlier before turn 7 to go faster down the back straight.
- brake earlier before turn 8 to go faster between 8 and 9, which translates to higher top speed on the main straight.
- go faster through the S bend (turns 10 and 11).



For session 5, I lowered my tyre pressures back down to 35 PSI front and 32 PSI rear. This reduced the understeer somewhat in the hairpins but I think the Dunlops need to operate at a lower pressure still. The rears were still a little slippery so the ideal pressures for the Hankooks on my car are lower still. Yods also came out as a passenger this session - another satisfied customer there.

By the final session, the track was cooling down and I just couldn't make the car go faster than a 1m:42s. There were many learnings that came out of the day and I think I know what needs to be done to get into the 1m:40s. A big thank you to all crew who made this first ever Exe Crew track weekend a success.

Saturday overall results here:
http://www.natsoft.com.au/cgi-bin/results.cgi?20/05/2012.WIN.S1

Saturday individual results here:
http://www.natsoft.com.au/cgi-bin/results.cgi?20/05/2012.WIN.S1.I

Sunday overall results here:
http://www.natsoft.com.au/cgi-bin/results.cgi?20/05/2012.WIN.S2

Sunday individual results here:
http://www.natsoft.com.au/cgi-bin/results.cgi?20/05/2012.WIN.S2.I

More of my photos here:-

Saturday
https://plus.google.com/photos/116784462637251109431/albums/5744966981978271425?authkey=CI3My-vY0Ouk0QE

Sunday
https://plus.google.com/photos/116784462637251109431/albums/5745376666518953553?authkey=CP2D4LeoqdGmOw

And here are a couple of photos by Eric Huang:



Saturday, May 5, 2012

Rear DBA rotor temperatures

The DBA rotors have three coloured stripes on the edge that change colour when they reach a certain temperature.

Temperature (degrees C)/Original colour/New colour:
  • 458 / Green / White
  • 550 / Orange / Yellow
  • 630 / Red / White
Upon inspection of the rear rotors today, I found the following:
Left hand side - only the green stripe had turned white, orange and red unchanged.
Right hand side - green stripe had turned white, orange stripe had partially turned yellow and red was unchanged.

So far these rotors have done one track day at Phillip Island and one at Sandown - both tracks are high speed and run anti-clockwise. Whether track direction causes more brake usage on one side is still a question I need to find an answer for.

Tuesday, May 1, 2012

[Photos] Sandown 29th April 2012

Here are some great photos from Sandown by Dan Lee. Thank you.

The full album can be seen here:
https://plus.google.com/u/0/photos/104728463250082923536/albums/5737189767665671377

Kam's supercharged Z, mine in the background.