I Am Agonizing T3 at VIR...

[FTS]

To end the aggony, I had to visit VIR once again, so I went for a day during the Marque Madness event Mercedes, BMW and Audi clubs organize last Friday. I had plans to test various theories we discussed here and the "How To Brake?" thread that has been very helpful to me in conceptualizing varying approaches.

I haven't had the chance to look at my data in every details, but few things emerged that were pleasant surprises. To set the stage, I am looking at three sets of data, March Zone 2 event, May FSR event and the last Fridays. Weather and tire conditions play a big role in the difference between data set, but the biggest factor was my driving attitude and approach where last Friday I was significantly cooperative with the car rather than forcing it to do things. My biggest offensive driving was during the May FSR event, when nothing felt smooth, cooperative or productive.

March: low 80s, low humidity, hot tire pressures: 32F, 34R, best lap: 2:10.0, TBL: 2:09.5, 5 heat cycles on R888s
May: low 90s, low humidity, hot tire pressures: 32F, 32R, best lap: 2:13.0, TBL: 2:11.4, ~20 HCs on R888
June: high 90s, very high humidity (heat index ~102-105), hot tire press.: 31.5F, 33.5R, best lap 2:11.7, TBL: 2:10.7, ~24 HCs on R888s

First, the best lap vs. TBL difference during May is a critical indicator on how inconsistent and pushy I was. Whereas during March and June, I was more consistent and cooperative (I am avoiding using the word "smooth" )

T3 data:
March time slip: 6.143 secs
May time slip: 6.310 secs
June time slip: 6.109 secs

Goal was to better position the car for the turn by not clipping the apex at T2, but coming in a little wider, braking more gently and carrying the braking a little closer to the apex. The following chart from RacePak shows how that looks from the accel Gs.

June lap shows a deficit of 8 mph compared to March lap; however, because of late braking with less force (-1.1 G vs. -0.8 G), the deficit turns into a 3 mph advantage by the apex. Additionally, because of releasing the brakes later but more gently (see slope of G traces), an earlier turn-in was possible while having a wider arc through the turn, which results in almost identical exit speeds for both runs. Although the avg. speed for March lap through the turn is 0.9 mph higher, the tighter arc results in a very slight improvement in segment time, 14/100s. The significance of this is that I could achieve the same performance between the laps despite negative environmental and tire conditions, because I was more gentle with the inputs and did not upset the car through this very transitional section between T1, 2 and 3.

In contrast, it is obvious, even just through this turn, that during May I was pushing the car and not cooperating with it, which resulted in slower times and much less fun ride. The May braking force similar to June, but for much less duration to "make up time," which is not possible, we just try to "loose less time."