HPDE1 experience in a 2010 WRX

[855T]

I originally wrote this for NASIOC, then gave up with the stupid image issues, and posted to /r/WRX, but I figured it should go here, too. There are still olds like me out there who come here for info first.



There's not a ton out there for those of us '08-'10 folks about track days with the WRX, so I figured I'd write something up in case anyone decides they actually like this generation and want to take one to the track.

• Event: NASA HPDE1
• Location: Willow Springs Raceway (Big Willow)
• Date: May 21, 2022
• Temperature: mid 70s in the morning, mid 80s in the afternoon
• A few pics of the car: https://imgur.com/a/0BFPZBL

This was my first time on a full sized track with any car, and my first time on any track with my car. I brought a jack, stands, and an assortment of tools, along with some premixed Subaru coolant and an air compressor.


Upon arriving at the track, I set my tire pressures at 31 front and 32 rear and headed to the classroom. If you have ever been to a track day or even done some karting, nothing in the classroom sessions will be new or surprising, but it does let you figure out who is going to be an absolute liability on the track. FYI, Toyota is giving free HPDE events to anyone who guys a GR86 or Supra, and every single person in one of those is going to be dangerous for at least the first session.


Once on grid, my instructor introduced himself and took a seat next to me. We talked a little about tires, a little about the car, and a little about my preferences. Then, we set off through pit lane and onto the track.


Big Willow is a fairly high speed course with one technical section and then a couple of higher speed turns. On the outlap, I tried to get a sense for the line while also figuring out if my tires and brakes were going to make it. We started pushing once we crossed the exit of turn 9 and I pretty quickly was able to catch up to and eventually get point-bys from slower cars like Miatas and 86s. Passing (and being passed) was not as scary as I had thought. On the other end of the spectrum, being aware of the manned flag stations and any displayed flags did not come naturally and I had to really make sure I was glancing at them every lap.


By about the 8th lap, the tires were pretty greasy, my brakes were fading, and the car was getting hot. I slowed down a little to manage all three items and was pretty successful. Beyond getting around the track, the first session didn't teach me much. My tire pressures were 40 up front and 39 in back after the session, so I dropped them back down to 31/31 and traded the tires left to right. Big Willow is really hard on the driver front tire, so I tried to rotate every tire through that position throughout the day. I will note that jacking up the car and moving wheels around this many times in a day was not ideal for my back.



In the second session, I started to pay more attention to the line and started shrinking my braking zones. This ended up helping a lot with both the tires and the brakes, and started to expose the limits of the car. It pushes/plows/understeers aggressively and, without some practice trail braking, just meant I had to be a little more cognizant of my turn-in point and speed to avoid overdriving the car. The brakes felt solid for the entire session and the tires felt a little better later.


After a fill up (I averaged about 7 mpg on the day) and trade of front tires to the rear, the third session started. You can see a video of this session here:

NASA SoCal HPDE1 - Willow Springs 5/21/22 - 2010 WRX - session 3 - YouTube

NASA SoCal HPDE1 - Willow Springs 5/21/22 - 2010 WRX - session 3 - YouTube

Overall, I was about 2 seconds faster in my third session than my second, which itself was bout 4 seconds faster than my first. Given the car's proclivity to understeer, my instructor started suggesting some alternatives to the NASA line which helped a little, and we started to experiment with light trail braking. Trail braking definitely helped the car rotate but felt way too sketchy by the last few laps as the tires greased up. I also saw the temperature gauge creep towards H at the end of the straight each lap, so I had the joy of running the last couple laps with the heater on.


In the last classroom session, the lead instructor mentioned how he was impressed nobody had yet went offtrack - I'd make him look dumb on the outlap next session. Before the last session, I swapped front tires again. I think I ended up doing a pretty good job equalizing wear, but personally think slightly higher tire pressure would definitely limit some of the tire rollover I was getting throughout. It's a compromise between grip and tire life.


My fourth and final session is here:

NASA SoCal HPDE1 - Willow Springs 5/21/22 - 2010 WRX - session 4 - YouTube

NASA SoCal HPDE1 - Willow Springs 5/21/22 - 2010 WRX - session 4 - YouTube

As you'll note, I had been working on my line through 8 and 9 all day, and managed to use just a little more than the full track on my turn 9 exit. The driver rear tire hit the dirt and lobbed me into a spin at 85 (

YouTube (Short URL)

YouTube (Short URL)

) , which was fairly easy to catch, but they warn you against trying to correct anything if you're going into the dirt, so my counter pointed me into the infield and I let it go without fighting. Going off gets you black flagged, so I returned to the pit after that lap, had a chat with the marshal, and then went back out. I cut another second off my time this session almost exclusively by managing a higher turn 8 entry and mid-turn speed. The car was pretty hot for most of the session - running the heater helped the car but made my feet pretty miserable.


I'd like to do some more of these going forward. Here's what I think anyone with this gen WRX should consider prior to a track day:

• better pads and brake fluid (Stoptech 309s and ATE Typ 200 worked well for me)
• cooling system upgrades (e.g. radiator, straight water, oil cooler, etc.)
• consider a 200 treadwear tire - the PS4S were fine but they're $250 a pop and you're gonna melt 10k miles off of them in 80 minutes on track
• consider sway bars to correct understeer and make the car, at least, neutral

Beyond that, I need to figure out why my cooling system is struggling, particularly given that I replaced the water pump, thermostat, hoses, and radiator less than two years ago. Since the track day, I have installed the Perrin oil cooler along with a Koyorad racing radiator - datalogging on coolant temps shows ~20 degrees lower on the street and an absolute max of 205, so I'm optimistic this has helped.

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[Craig_B]

Originally Posted by 855T

This was my first time on a full sized track with any car, and my first time on any track with my car.

Congrats on getting out there! So many people are afraid of tracking their sports car. NASA HPDE1 is my #1 recommendation for anyone looking to do a real track day with an instructor.

FYI, Toyota is giving free HPDE events to anyone who guys a GR86 or Supra, and every single person in one of those is going to be dangerous for at least the first session.

My NASA instructor wasn't too fond of this program, but I guess it does help get people on track. He said "Watch out" every time I came up on one.

I'd like to do some more of these going forward. Here's what I think anyone with this gen WRX should consider prior to a track day:

better pads and brake fluid (Stoptech 309s and ATE Typ 200 worked well for me)

Consider dedicated Track Pads & Rotors if you plan to keep tracking the car. I'm a big fan of the Carbotech XP12's up front and XP10's in the rear. They work really well on my car. Just don't expect them to last long.

cooling system upgrades (e.g. radiator, straight water, oil cooler, etc.)

This is definitely a must.

consider a 200 treadwear tire - the PS4S were fine but they're $250 a pop and you're gonna melt 10k miles off of them in 80 minutes on track

200TW tires with track pads & rotors = a lot of fun. I'm currently using the Dunlop Direzza ZIII's for track duty. They are the least "greasy" feeling of any tires I've tried so far.

consider sway bars to correct understeer and make the car, at least, neutral

Coilovers. Coilovers will give you way more control to get the car neutral. Cygnus or Fortune Auto. Expensive, but worth it. My car is way more predictable and 2+ seconds a lap faster just from coilovers.

Beyond that, I need to figure out why my cooling system is struggling, particularly given that I replaced the water pump, thermostat, hoses, and radiator less than two years ago. Since the track day, I have installed the Perrin oil cooler along with a Koyorad racing radiator - datalogging on coolant temps shows ~20 degrees lower on the street and an absolute max of 205, so I'm optimistic this has helped.

You'll be good with those upgrades. I run a Mishimoto radiator and oil cooler on my car since I'm in Florida. It still gets hot, but doesn't overheat. I'm good with taking it easy for one or two laps a session to help bring water temp back down.

[855T]

For what it's worth, I kinda wanna stay lower grip so I have less risk of oil starvation...plus it's fun.