The All-New GR Corolla World Premiere April 1, 2022

[WolfpackS2k]

Was able to "cash in" my "free" NASA track day a few weeks back at VIR. Going into this I assumed it would be a normal HDPE schedule format (4 sessions, each 20-30 minutes in length). NASA didn't proactively send me a schedule, so last Tuesday I looked it up and to my delight, discovered that I was going to be able to be on track for up to 205 minutes if I so desired (split into 6 sessions). That's crazy to me - much more than I'm used to, even from a 2 day weekend event. This created a dilemma for me, as I had not purchased track pads (since I didn't/don't really have intentions to actively track this vehicle). But, when offered 200+ minutes to have my way on track at VIR...I scrambled to find track pads. And sadly was unable to do so within the roughly 60 hour window I had given myself. So I did the next best thing and purchased a "backup" set of OEM front pads then replaced the brake fluid with Castrol SRF. And given my tires are the OEM spec Michelin Pilot Sport 4 with a 340TW rating, I didn't think the brakes would end up overheating.



The first 3 sessions went really well. Weather was 50-60°F and sunny. I've never tracked an AWD car before so (whether I realized it at the time or not) I started out by driving the car as if it were RWD. With that as a starting point I adjusted to the handling characteristics of this car and gradually changed my lines and techniques. This resulted in dropping roughly 5 seconds off my lap time (taking fastest from session 1 to fastest in session 3). The GRC understeers less than one would think, however for some of the slower tight turns its noticable. But this is where the AWD mindset started to take over. The GRC reacts quite well to line adjustment via lift throttle. So do that, car rotates in a minor 4 wheel drift, then floor it and the car follows the proper line. I ran all 6 sessions in 50/50 AWD Track setting, Sport Mode, and either Expert setting (TC & Stability control mostly off) or Everything off (hold TC button for 3 seconds). In moderate speed turns where one would expect a front heavy car to understeer under power the GRC would instead pull/push itself along the steering line. I'll admit it took me a while to trust this behavior and I never quite fully committed to this. As I learned how to properly use the AWD more and more the inevitable happened. Right after setting my fastest lap, roughly 4-5 turns later the AWD controller overheated and the car put itself into FWD mode. I stayed out a few more laps to see how the car did with only the front wheels getting power. Honestly it wasn't that bad but it wasn't my cup of tea. I was around 2 1/2 seconds slower that way as well. For all the dry sessions the tires were easily overheated if pushed very hard. They would get greasy and understeer would be exaggerated. To even out the wear I rotated the tires after the first 2 sessions. The brakes also got hot at times and once or twice the pedal went all the way to the floor. Many of my sessions only had 35-40 minute breaks in between so during that time I had fans blowing on my front wheels.

I only had one "natural" rival in my group that day, that being an FL5 Civic Type R that was running on aftermarket wheels and what I can only assume sticky tires. And he was faster than me, but not by much. I also noticed that even with his upgraded rubber I had a considerable speed advantage through slower turns.

During the lunch break the weather changed and rain moved in. This gave me a wonderful opportunity to learn the car even more. Oddly (to me at least) the first wet session of the day was attended by...only me! For 30 minutes I was the only car on track. The rain was infrequent and never heavy, so the asphalt was extra slippery. I had one "whoopsie" moment at the top of the Uphill Esses when I was slightly offline and the rear end tried to come around at roughly 90 mph but otherwise the car was very stable and competent. I discovered that the fastest line for me through Hogpen involved letting the car intentionally 4 wheel drift for just the briefest of moments, and it reacted the same every lap during that maneuver. Very predictable. For the 2nd wet session the rain was ever present and even moderately heavy at times. Were 15-20 cars on track for that and I was by far the fastest, haha (surprise!). The CTR was on track again, and I can only imagine struggling a bit to put the power down, because over the course of 30 minutes I almost lapped him. Accelerating out of every turn involved no wheelspin so my velocities were roughly the same, I just braked earlier because I'm not insane. Still, 128 mph in the rain is nothing to sneeze at. Before the 3rd session started the sun came back out and the track started drying off. I checked my brake pads before the final session and they were quite thin. However I only had 25 minutes before the session started, and had already decided that I really don't want to keep using OEM pads (so much dust) so I told myself I'd just "go easy" on the brakes for the last session and come in early if it seemed right.

All in all it was a lot of fun and the car really impressed me given the platform's humble origins. If I could tweak anything it would be the obvious, upgraded brakes and tires. Though the worry with upgrading tires is exacerbating the AWD overheating issue, for which I'm not currently aware of a legitimate fix. Otherwise, my observations are: the factory seats suck for "aggressive" driving. I spent so much effort bracing myself in the car that parts of my body were sore the following day (and not the usual parts post track events like neck, shoulders, arms, etc). As expected, the engine is far too quiet. Above 60 mph it was almost impossible to hear it through my helmet. Hell, the GoPro mounted to my helmet barely even picked up any engine noise. I bounced off the rev limiter more times than usual as a result, in spite of the excellent tachometer/shift display. The pedal spacing sucks for heel toe (no surprise here) so I actually let the iMT do it's thing and rev match for me. Oh and my car decided it was smarter than me and called 911 Services 5 times before I could get it disabled. That was a fun distraction while driving LOL.

Comparing lap times between cars (on different days no less) is always a flawed comparison but my best time was roughly 5 seconds slower than my best in the C63 (which was set on worn tires no less), with a roughly 5 mph lower avg speed. Highly respectable IMO. The 3 cylinder in the car proved to be quiet thirsty for the day and I had to fill up the tank twice. That worked out to an event average of around 8 mpg. Thermal management (outside of the AWD) was impressive and I never saw oil temps above 260°F. The majority of the time they were actually below 250. I ended up turning 69 laps that day, for a distance of 225 miles. Which is massive IMO. There were a lot of other GR Toyota owners out there (Supra, GR86, GRCs) but sadly they all had registered in the Intro group which lumped them in as beginners. They got more classroom time than track time (2 sessions) but I chatted them up and everyone was pretty nice.

Few videos:
Fastest dry session

And a wet session

FYI the overlay data is slightly out of sync with the video. Haven't figured out how to fix it (was done automatically by the app).

[Ohio Enthusiast]

savagegeese released an in-depth ownership review of their GRC. They touched on track-readiness and modifications which I found very interesting. It seems to me that the Corolla roots heavily affect the car and it's not an easy "pads and fluid and thrash it on track" kind of car.

• Overheating the 4WD clutch pack within 12-15 minutes (no solution yet, and difficult to engineer one due to tight space and sealed unit)
• Engine oil temps reaching 290 within 15 minutes (oil cooler helps)
• IAT temps cutting power and heat soaking the engine (aftermarket airbox helps)
• Installing coilovers or camber plates in the front requires taking apart coweling and cutting a sheet metal brace

[WolfpackS2k]

Originally Posted by Ohio Enthusiast

savagegeese released an in-depth ownership review of their GRC. They touched on track-readiness and modifications which I found very interesting. It seems to me that the Corolla roots heavily affect the car and it's not an easy "pads and fluid and thrash it on track" kind of car.

• Overheating the 4WD clutch pack within 12-15 minutes (no solution yet, and difficult to engineer one due to tight space and sealed unit)
• Engine oil temps reaching 290 within 15 minutes (oil cooler helps)
• IAT temps cutting power and heat soaking the engine (aftermarket airbox helps)
• Installing coilovers or camber plates in the front requires taking apart coweling and cutting a sheet metal brace

Not many cars are ready to go with pads and fluid, but this car is far from unequipped to handle it. First I'll address your points above then add a few others.

Yes the AWD controller can overheat. However, as I clearly stated above it didn't happen to me until my 3rd session, and after 7 laps (roughly 15 minutes). The jury is out on whether heat wrapping the exhaust and adding insulation to the ITCC temp sensor (which is what I did) have any benefit. However yes, people are working on a fix. I know of someone currently beta testing an additional "water jacket" that is installed on the outside of the housing and contains coolant (with a pump). This Housing also relocates the temp sensor to the other side (away from the exhaust). Will it work? Not sure, but I didn't buy this car to track it so I'm not closely following it.

"Engine oil temps reaching 290 within 15 minutes". Not sure what to say about that. I ran 35 minutes on track and my oil temperature never topped 260°F. And that's nothing to worry about. My C63 tops 280 and it has an oil cooler the size of my head. This car doesn't need an additional oil cooler (it has a small one from factory).

"IAT temps cutting power and heat soaking the engine". While I agree that OEM design (for extra airflow) isn't ideal, I didn't experience any heat soak issues on track. And looking over my data log from my fastest sessoin, IAT peaked at the beginning of my session (probably from my car idling in the queue) at 80°F. During sustained hot laps the IAT was 60-65° (roughly 10 degrees higher than the ambient temperature).

Point about coilover installation is valid. However you can gain up to 3 degrees of negative front camber with OEM Toyota crash bolts, at a cost of less than $30.

I wouldn't buy this car as a dedicated track vehicle. That's what a GR86 is for. But as a do everything car that can occasionally be tracked hard, it excels.

[Ohio Enthusiast]

Originally Posted by WolfpackS2k

Valid response

I was just passing along what they said in the video. Most of the technical "faults" were discussed starting from the 11:09 mark with Limit Plus 1 that claimed that they are using their GRC for aftermarket development and ran it on several tracks.

Frankly I have no dog in this fight as my BRZ turned me into a lightweight-ish RWD snob (after owning a Focus ST for a year prior to getting the BRZ), but that's neither here nor there.

[WolfpackS2k]

Hahahaha. Sure I mean its good info to have out there, and far better than stuff some keyboard warriors make up!

I'm a RWD snob myself, but may be in a living situation soon where I'll need AWD. Hence this car

Also seems odd to have such drastically different oil & IAT temps than what Limit+1 is seeming. Not even remotely close.

[Irace86.2.0]

[vh_supra26]