SCCA PDX 08232019 – Autobahn South

After 2.5mo hiatus, back on the track at Autobahn Country Club South. A good number of minor tweaks were made to the car, and some significant driving changes for me.With picture perfect weather, I was really looking forward to seeing what I could run in the car. I set a rough goal of a 1:40, with 1:38 being a small reach. The Grid Life Street AWD (my class) record from Autobahn earlier this year was ~1:37.9, so I thought this was a  appropriate goal, given my 1:41 from earlier in the year.

This was also my first time instructing for SCCA. Unfortunately, as novice runs right before advanced, it makes getting back to the car in time a little tricky. After instructing for their first session, by the time I got into grid for my second session, I was at the back of the line – resulting in a lot of traffic, and I was unfortunately unable to get a faster lap in for the second session. I lined up somewhere in the middle on the 3rd lap, and I had about 2-3 laps where I was open or nearly open, which is when I set my fastest laps.

To the car:

  • Added slightly more camber in front (3.1 to 3.5), slight toe out in front for better turn in.
  • Decided to swap in Girodisc s/s pads – not as capable as the ST43s*
  • Flushed in Motul RBF660, decided to leave it in for one event not to be wasteful. Castrol SRF will go back in*
  • Flushed the clutch
  • Rebuilt calipers – to same specs, one caliper was leaking
  • New brake lines – AMS stainless steel to Stoptech SS. Some wear on the rear AMS lines
  • Egr block off plate – recommended for knock by tuner, still had knock at track
  • new ACD tune, based on stock, more open on turn-in, variable lock on throttle. Seems similar or marginally different to the ER tune. May swap back and forth at next event*
  • OEM FSB bracket – got rid of the Cusco multiple hole bracket for FSB, never used it anyway

* to be changed for next event

To driving:

  • Way better lines, replacing late apexes for more cornering speed
  • More trail braking
  • Getting on gas hard after apex

With these tweaks, I was able to drop a lot of time. On the very first session, with tire pressures not right (set at 31/34 cool – ended around 40F/40R), I ran a 1:37.7 – already 3.5s faster than my fastest lap from the last event, which was damp, and faster than the AWD GridLife Street record.  By my open laps in the third session, I only dropped another second, resulting in a 1:36.77 – a phenomenal time for my current level, and a time that I would have been a hard reach for sure. The lap still had a LOT of errors, as I was still experimenting with different braking points at the time. Working on adjusting future targets, and for now, looking forward to getting the M3 out there!

Fastest:

 

Full laps:

 

IMG_1776IMG_1777IMG_1805IMG_1806IMG_1807

Set Up:

  • 24psi tune, 93 octane, 310hp
  • Ohlins DFV, 8k/11k; Shocks 6/5
  • Tanabe FSB; WL 26mm RSB; Soft
  • DC-ACD: 3; OS Giken Rear Diff
  • Camber at -3.5, -1.9 rear,  -1/32nd toe front 0 (erring on negative) toe rear
  • Brakes F: Girodisc 2-pc & S/S; Brakes R: Girodisc 2-pc & S/S
  • CE28N 18×9.5; 255/35-18 Bridgestone RE71Rs
  • Various levels of fuel throughout track
  • 36psi all around on RE71Rs

Notes:

  • Changes to trail braking helped carry more speed into corners & rotate
  • Look up, look ahead
  • Corners 1-2-3 – Stayed outside on corner 1 for a better line/angle. Missed apex for corner 1. Squirt gas to 2, then release and wait until WOT – all the way through 3. Cowboy exit and hold on
  • Corner 4 – Braked at 2, but let go of brakes too early. Trail in through the apex & WOT
  • Corner 5 – Too slow. Braked before 1, get off hard brakes, trail in & carry speed, then WOT out
  • Corner 6 – Still unsure here. Swung further out to the left, helped line. Brake, and trail in and swing right, look up for true apex
  • Corner 8 – Braked at 3 board, trailed in – decent here.
  • Corner 9 – Missed apex due to confusion, brake at end of rumble strips & trail in a lot
  • Corner 10 – Squirt of gas, then get off, look up, turn in earlier, and WOT cowboy. This was not improved this event, fix this somehow. Earlier apex?
  • Corner 11 – Braked at 5, I think 4.5 is solid and trail it in more to carry more speed into it, maybe a little earlier, and WOT through 12
  • Corner 13 – Braked at 2, turn in a hair earlier to apex by 13’s rumble strips and carry more speed through that, trail until rotation and WOT.
  • Added 5 gallons after the 2nd session, was plenty of fuel. Keep 4 in a can and add after Session 2.

Tuning changes for next time:

  • Try English ACD tune again, switch if sucks.
  • Castrol SRF, ST43s
  • Tweak tune, still knocking – pass on this, adding Intercooler & hopefully the 100 cell cat
  • Rebuild the OSG by TRE

2019 Track Days: 3 (3 on RE71Rs)

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