Tuning a Toyota GR Corolla: What Could the Aftermarket Do For the Latest Hot Hatch?
If the GR Yaris is anything to go by, the future looks quite bright for the GR Corolla’s aftermarket.
The 2023 Toyota GR Corolla (GRC) has been officially unveiled and automotive media is buzzing with excitement. Like, straight-piped Mazda 12A rotary levels of buzziness. This neat hatch's debut got me thinking: what will aftermarket tunability look like?
While it'll be some time before driving impressions hit the presses, all signs point to this hot 'Rolla being a lot of fun: all-wheel drive that can send as much as 70% of the power to the rear (so, drift-able), 300 horsepower for a 1.6-liter inline-3 (as Kristen Lee points out, more horsepower per liter than a dang Bugatti), 6-speed manual-only, and a relatively low curb weight of 3,249 pounds, all wrapped up in a sporty package with looks to die for.
But there's another sign that indicates the GRC will be a lot of fun to drive: it's built alongside the GR Yaris (GRY) in Toyota's GR Factory in Motomachi, Japan, and shares the exact same engine and drivetrain (albeit with more power). Our comrades in automotive media around the globe have said immensely good things about the GRY's fun factor, including our very own Lewin Day.
This all made me quite curious. If the two cars share the same engine and drivetrain, and a lot of the specs seem to match up between their respective press materials, what can we hedge on with some confidence about the CRC's aftermarket potential? Particularly, what kind of aftermarket parts will make it brake harder and handle sharper? With a little detective work and some photos I took at the GRC debut event, there are some solid possibilities here.
GRY reviewers and owners have reported that its stock brakes are very good from the factory. "The brakes, too, are predictably giant-killing in their stopping power." James Dennison pointed out for Which Car? Australia. "Four-pot at the front and two at the back, the former’s disc size is – believe it or not – is larger than the Toyota Supra’s."
After a quick scan of the forums, owners have shared positive impressions, too. It sounds like they hold up well in fun driving scenarios, but for serious track work, aftermarket pads seem to be recommended, as they'll deal with heat better, and have better modulation and feel.
Does this mean the GRC will have similar qualities, as well as take aftermarket pads that are already available for the GRY? Comparing media assets and photos I took last night, things are looking up. It's a little hard to see, but it looks like the Corolla shares the same four-piston calipers and two-piece rotors up front, and two-piston calipers with vented one-piece rotors out back. Also, my colleague Chris Rosales pointed out that according to Toyota personnel, the GR Corolla has 14-inch rotors up front and 11-inch units in the back, which tracks with the above graphic's GRY specs. Factoring in the GRY's lightest trim weight of 2,821 pounds, it's 428 pounds less than the current-known GRC curb weight of 3,281 pounds, so it's unclear if there will be a difference in factory pad compound between the two to compensate for this.
Sidenote: thankfully, the GRC has 32 more horsepower to compensate for this added weight.
At the moment, the differences in suspension design and tuning between the GRC and GRY are unclear. It's too early to point out whether they share the same springs, damper tuning, and sway bars, as the Corolla is built on Toyota's populous Global Architecture-C (GR-C) platform, and the GRY is built on a modified Global Architecture-B (GR-B) platform that features the GR-C's rear.
Then, there's the obvious weight difference and the fact that the current, non-GR Corolla hatchback has a great selection of aftermarket suspension goodies available in the USA. As does the GRY elsewhere in the world.
From personal experience, usually, platforms that are shared between different models, or even different makes, like my Mazda 2 and the Ford Fiesta ST, mean that suspension can swap over just fine. However, it's a one-way street: ideally, only the suspension from the heavier Fiesta ST should go on a lighter Mazda 2, as suspension that's valved for the Mazda 2 might not accommodate the added weight of the Fiesta ST, and thus might blow easier, not ride as well, and so forth. Conversely, when suspension that's valved for more weight goes on the Mazda 2, it means an ever-so-slightly stiffer ride, and presumably more parts longevity.
Plus, the GRY is a special case, as it was custom-cobbled together as a homologated rally car. But still, you would think there are some similarities due to being produced alongside each other in the same factory.
Or, none of this even matters and only suspension from the non-GR Corolla hatchback swaps to its hotter sibling! Still, it's all fun food for thought, and I'm sure we'll get more clarification in the coming months about both brake and suspension specifications. Hopefully, Toyota coordinates with SEMA like it did with the GR86 and provides a measuring session for the aftermarket and media to figure all of this out.
Got a tip? Send us a note: firstname.lastname@example.org