SCCA PDX 06012018 Autobahn South

Had my first track day since 2016 – this is a culmination of most of the prep that I’ve done this off-season; namely, improving the brakes and oil systems. With the brakes, I jumped from 320mm rotors to the 350mm rotor setup of the evo X. This also meant going larger wheels and tires, and while I kept the same width as 2017, I went with 18×9.5 CE28Ns. The last time I was on the track was roughly 2 years ago; suffering brake failures at both events and persisted long after the events. The odd thing about the first and second brake failures was that they were unrelated. The first brake failure, aside from the pad getting worn through, is a mystery in that the brakes were bled and new pads were added, but still did not feel right. The second brake failure was with the Girodisc S/S pads and new DBA 4000 rotors, as well as their ti shims which were poorly designed, and the wear hump on the back of the pads made it so the ti shim did not sit flush. This caused my brakes to be soft the second time through, and not only were they soft, the pads were pressed up against the rotors every time the shim straightened out (when i got off the brakes), causing massive overheating issues & boiled the fluid. I did not know it was the shims at the time, and this resulted in me replacing literally every component of the braking system, including getting new brake master cylinder, new SS brake lines, new Evo 9 calipers, powdercoated & rebuilt with SS pistons & high temp seals. Obviously, the calipers did not fix the issue, because the problem was in the pad shims, not the calipers.

I hadn’t gone back to the track since getting the new E9 calipers, but the braking performance still left something to be desired. The car just didn’t feel like it was braking very hard. I spent all of 2017 autocrossing on this setup, and at the end of the year, made the decision to re-prep the Evo for track. Instead of testing out how the new calipers would do, I decided to revamp the entire system, again, to both improve general braking performance as well as mitigate any track issues. As written above, this meant going to the larger X brakes for improved braking performance & a larger heat sink. I got true track pads, Raybestos ST43s, with titanium shims that sit flush against the back of the pad this time, have un-broken brake air guides, and fresh fluid.

I spent a few autox events this season breaking in the new setup, just so the first time I was on the system wouldn’t be on the track. The new brakes are great. I thought that braking couldn’t improve much, given that ultimately it’s dictated by the grip of the tires, but I was wrong. It’s much, much easier to brake, hard, and slow the car down effectively. They’ve stopped the car when I didn’t think it would, and they’ve handled hot autox (95 degrees) well so far, and I’m eager to test them out on the track. Fingers crossed that this time, I have no pad failures, shim issues, caliper melting, or fluid boiling! With the larger brakes, this is also going to be the first time I’m on aftermarket wheels on the track. The first few events were on the OEM 17×8 setup, and this setup has much more grip – meaning higher g’s generated through corners, with one caveat. I’ve noted an approximate 1s differential (new setup is slower than 17×9.5s, faster than 17x8s) between these tires and 10mm narrower RE71Rs (on my old 17×9.5 setup) in autox. I imagine this differential will be larger at the track.

The second main improvement came with the oiling system, in two forms: first, with the larger oil pan. Previously, I had the Buschur/Jun baffled oil pan, where they simply weld in a few walls to better direct the oil. I believe this helps, but not near enough the extent it needs to to keep the pressures up. There was a group buy for the Racefab wet sump on Evom, and despite the cost, decided to go for it. The pan is a heavily modified OEM pan, complete with all the requisite trap doors and baffles, and adds roughly 2 quarts in capacity. The increase in capacity already physically helps prevent oil starve, as there is simply more oil in the system. The baffles and trap doors help keep the oil in right place, and the oil pickup itself was moved further back to a more optimal location. All of this to help prevent oil starvation of the car in extended right hand corners.

Finally, I added a Maperformance/Setrab oil cooler. At first, I had a few issues with the lines leaking. MAP graciously hooked me up with a second set of lines, and it turns out that this time, they added some crush washers inside the AN fitting, something I had never seen before. I got the lightweight black braided line option, and after swapping the lines, have not had any issues. This is just to provide improved cooling for the oil system on the Evo as the car is punished at track events. There were a handful of other less performance oriented mods done over the offseason, but these were the main areas I wanted to hit. The mods I did overall actually don’t make the car any faster, and may actually make the car a little slower straight-line, but are well worth the reliability they add.

The track day was with SCCA PDX, on Autobahn South – the same group that I did the September 2016 track day with. In addition to the changes mentioned above, I have made a number of tweaks. The suspension has been tweaked a number of times, and the setup now is with a slightly more aggressive alignment and shocks set stiffer, with the RSB on the stiffest setting.

Friday was ideal, with no clouds, starting in the high 70s and cooling to low 70s/high 60s. Most importantly, the car had zero issues, with brakes or otherwise. I had no fade or any issue with the brake system, which is amazing for me. I am still going to flush in Castrol SRF for my next track day, but otherwise look forward to rebuilding my confidence in the brake system to brake harder & deeper into corners.

The rest of the setup performed fine, though the lack of grip from the RT615k+ was apparent. To my surprise, a lot of tire noise from the front, and a touch more understeer than I expected, given the overall increase in looseness made to the car. Even in the flat out section between 6-7, which is a kink you can take WOT, the tires would give a small chirp of protest no matter how gently I turned for the kink.

While I don’t want to make any setup changes based on these tires, I think I am ready to get the car a little looser for racing: namely via a more aggressive ACD tune & a softening of the FSB using better endlinks & brackets (http://cirodesignracing.com/suspension/). Likely will be for the 2019 season. For now, I will likely continue running this setup, and focus on improving my driving & line before adding more grip.

PDX/HPDEs tend to get very crowded, as there is only point by passing, and traffic can build up. I purposely started as the first car in the 3rd session, and started the warm up lap very slowly in order to give myself maximum space between me as the first car, and the last car in the session (ie from lapping). I got in about 3 open runs, and there was such a gap between the very last car and the next to last car that I got in another open run there, which happened to be my fastest. The first 3 laps were extremely consistent, 1:44.xx, tenths apart each run. My quickest lap was roughly 1:43.8x. It’s hard to measure without actual data taken, but after a few stop watch timings I’m confident this is about what I ran.

All videos below.

Fast Lap:

Chasing down Camaro:

Session 1 Inside:

Session 1 Outside:

Session 2 Front (black flagged due to off-track BRZ):

Session 2 Outside (black flagged due to off-track BRZ):

Session 3 Inside:

Session 3 Outside:

Session 3 Front (camera hit bug early on):

 

Set Up:

  • 20psi tune, 93 octane, 300hp
  • Ohlins DFV, 8k/10k; Shocks 6/5
  • Tanabe FSB; WL 24mm RSB; Full Stiff
  • ER-ACD Gravel; Cusco RS Rear Diff
  • CE28N 18×9.5; 265/35-18 Falken RT615k+

Key takeaways:

  • Car feels great, updates made to the car are performing well
  • RT615k+ is a little lacking, less grip & feedback than RE71Rs, mirroring my impressions from autox. Car understeers a little more on this setup, lot of squawk from front of the car during turn-in
  • Braking system is finally up to par. Will still flush in SRF, and start pushing the brake system next track day
  • Find proper braking zones, usually braking deeper to avoid lifting too much prior to corner entry
  • Continue to work on line, apexing, and powering out of corners. In general, can turn in a little later
  • Add in cornering speed little by little

Notes (Evo):

  • Started at full tank, lost about 1/4th tank per 20 minute session
  • Camber at -3.3, -1.9 rear,  0 toe front 0 toe rear
  • High temp paint on rotors did not white out the last red stripe, meaning the brakes ran cooler than before
  • 34-36psi all around (RT615k+)
  • ACD: Gravel, Dampers 6/5 F/R, RSB on stiff
  • 2018 Runs: 20 (6 on RS4s, 14 on RT615k+)
  • 2018 Track days (1 on RT615k+). Tires wear great, no visible maladies from 3x 20min sessions on Autobahn South

 

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One thought on “SCCA PDX 06012018 Autobahn South

  1. Pingback: SCCA PDX 06082019 – Autobahn South | Racing Blog

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