Wednesday, October 3, 2012

Watkins Glen Data Crunching

So typically when I get back from a track session, I'll go back and look at my data to analyze.  I'm going to start to try to post some of my findings here to help as sort of a basic data "coaching" process.  This is the basic of the basics.  Just looking at speed and how that translates to time.  Of course, Im available for hire too :P

So here goes:

Here is the first screen grab.  I usually prefer my AIM data, but Traqmate presents a more colorful layout for us to look at.  In this plot to your right, the main difference coming out of T2 is a shift difference.  But as you can see from the red line, it translates to about a 1-2MPH difference in a good portion of the track (roughly 1000').  That equates to a 0.1 second time difference alone.  Might not be much, but from the whole track, those tenths add up fast!!!

The next glaring and obvious difference in the plot is the entry for the Bus Stop (in the turquoise color section at roughly the 6500' mark).  In the red plot, I brake a good 200' before the blue plot.  This results in a bus stop entry speed difference of 7MPH translating to a bus stop exit difference of roughly the same (6MPH).  Now again, this distance traveled is "only" about 1000' but that difference in entry and speed results in a whopping 0.75 seconds of time difference.  Are you keeping track?  We're at 0.85 seconds of improvement already.

To the far right of the plot, we have the carouse or the "outer loop" as they call it.  By looking at the plot, you only really see a hairline difference between the plots.  3MPH to be exact, but youre travelling a fairly long distance.  This results in 0.2 seconds!  Still keeping up w/ your math skills?  Now we are at a little over 1 second gap!

The next plot here is the T9-T11 complex.  As seen by the red line, braking just 100 feet earlier and a 4MPH difference in minimum corner speed here, we get a whopping 0.5 seconds.  HUGE.  Now were at 1.5 seconds!

Again, the exit of T9 appears to be just a hairline difference in speed of only a couple MPH, but that's another couple of tenths!  (1.7 sec delta now).

As we enter T10 and T11, there is a 2MPH entry difference.  Mid-corner speed difference is 4MPH in T10 (a very high speed area and worth lots of time).  The T11 entry speed also differs by 4MPH and this segment yields another 0.5 seconds of time (2.2 sec delta now).

I will say though, out of all the corners, obviously T1 is critical. I could not find a good lap by lap comparison to highlight this as there were various inconsistencies (traffic, shifts, etc) to show a good back straight time difference.  One portion I will highlight is T1 braking and T1 exit as this is equally important.  As seen in the plot to the right, we brake 100' earlier in th red plot and there is roughly 4MPH speed difference.  The blue plot is obviously preferred as you can see by the parabolic shape that gradually enters the corner that trailbraking is being applied in entry.  That speed is carried into the corner and you can get a speed which is similar on exit, but you've now travelled that distance 4MPH faster.  Time?  0.5 secs.  (2.7 sec delta now).

If I could plot out a good back straight comparo, you'd likely see a 1-1.5 second difference if you exit T1 4-5MPH faster.  That's it for this episode of WongData Crunch.  Hope it was helpful.  My best laps logged was a 2:02.55 in GTS3 trim.  HP dyno'd was a healthy 282.  Impound weight after the race was 3116#s which is right at the limit pretty much.

Monday, October 1, 2012

Watkins Glen 2012 NASA Recap

So as is the case every year, going into the event meant constant forecast checking.  Rain or no rain?  Though this year did have one curveball.  We have a baby due!  My wonderful wife let me make the trek and I was ready to book it home if needed.  Lucky for us, baby held off.

It ended up being dry on Sat but a cold, rainy, and wet Sunday.  My goal this weekend was to try to reset the track record held by Josh Smith for the past couple of years.  Back then, he first started racing his E46 M3 and it was pretty undeveloped.  A lot has changed in two years for E46 builds.  We now have very nice GTS3 detunes which keep torque up but peak horsepower low (EPIC Motorsports).  There are new aero parts courtesy Bimmerworld as well as a new suspension package from Motion Control Suspension (MCS) (the old school Moton guys).  That time was a 204.7 in a 300hp car weighing over 3300#s with a stock diff.

Fast forward to now.  Both me and Josh have almost every part imaginable for our cars and they are fairly identical.  I think the only difference really is he has Ground Control swaybars and I have Hotchkis.  I've also got completely stock calipers with Performance Friction Direct Drive rotors (

So in the race, I had to make my way around some faster out of class cars before I got open and clean track.  Unfortunately, my SmartyCam was not working (just one of my electrical issues this weekend, more to come on that) so all I have is a choppy live stream video via UStream through my iPhone.  You can view it here:

Once I got open track, the last two laps would prove to be the fastest.  My logger said 202.55!!!  That is a full 2.2 seconds faster than the prior lap record and sure to fuel talk in the paddock.  Unfortunately, this is where my second electrical issue came.  My transponder quit working.  After 10 years, I guess the wire is now hard and brittle.  It snapped at the fuse link connection rendering all my times unconfirmed and unofficial.  My race win was even not showing up.  I ended up having to plead my case to multiple race officials who ended up ruling that I did in fact "win".  But without official timing and scoring, I dont get the joy of nabbing that record :(

Here is a data plot of my two fastest laps.

It shows I was entering the bus stop over 90 MPH which is insane in my opinion.  Top speed was only 138MPH using a T1 exit of roughly 75MPH.  As a comparison, Josh's old data pegged him at 145MPH top speed.  I also voluntarily put in a "black box" because I knew there would be paddock talk of fast times.  I sat down and analyzed the data with the GTS director and Im confident that it doesnt show anything out of place.  We compared his car's acceleration slopes and they were much steeper than mine implying I actually might have had less horsepower.

Sunday's race was wet and rainy.  I managed to qualify top 3 overall in the race group which is good in a rain race because of possible carnage in the starts.  I lost some ground in the start and some Vettes go by, but I managed to retake the lead and win overall.  Couple of videos:


I almost forgot to mention that having remote reservoir shocks is freaking amazing.  This was me pre-race after it was apparent the rain would not let up.  Instead of dilly dallying with spring changes, swaybar disconnections, etc... all I did was drop the canister pressures down and the car felt amazing!  Only downside is that it takes surgical skill and precision to bleed out the proper amount.  First time I lost all pressure in one but luckily a nearby Vette crew had nitrogen ready (I had a tank but not setup w/ regulator, etc and it was 10 min to grid!).