A great deal of care has gone into creating and maintaining this Toyota C-HR R-Tuned, a one-off, race-tuned special first exhibited at the 2017 SEMA show. Multicolored paint marks are on almost every bolt head, and there’s a log of cylinder-leak-down test results written atop the thick, aluminum radiator. Tastefully modified body panels fit snugly, unsightly electronic components are tucked away, and the welds on the eight-point roll cage are perfect. This attention to detail ensured a successful SEMA debut, but don’t confuse this for a lifeless concept car.
A great deal of care has gone into creating and maintaining this Toyota C-HR R-Tuned, a one-off, race-tuned special first exhibited at the 2017 SEMA show. Multicolored paint marks are on almost every bolt head, and there’s a log of cylinder-leak-down test results written atop the thick, aluminum radiator. Tastefully modified body panels fit snugly, unsightly electronic components are tucked away, and the welds on the eight-point roll cage are perfect. This attention to detail ensured a successful SEMA debut, but don’t confuse this for a lifeless concept car.
he deputy chief engineer for the C-HR, Hiro Koba, is a racing nut who celebrates Toyota’s concept of waku doki, which means “heart-pumping excitement.” Koba insisted that the C-HR (which stands for Coupe High Rider) have a stable chassis, balanced steering, and be dialed in on the Nürburgring.“The more you steer it, it turns exactly that amount more,” says Gardner of the stock C-HR. “The more you push on the brake pedal, it brakes exactly. It’s not overboosted; it’s responsive.”
We find his characterization fair but overstated when we drive a standard C-HR around a short road course at Willow Springs International Raceway in Rosamond, California. The C-HR is well damped and fun enough to toss around at speed, sure, but its meek engine and moaning CVT are turnoffs that had us calling it “okayish by default” in our test report of the stock model. We do a few laps, head back to the pits, and ask Gardner to tell us more about the R-Tuned and walk us through the build, which he says required more than 10,000 hours of labor.
Setting the Bar Really High
“[Koba] didn’t know how far we could take it, but we set the bar at supercar performance,” says Gardner. It’s a target that Toyota announced at SEMA had been achieved by lapping the long course at Willow Springs in 1:25.22, which is quicker than serious machinery such as a Nissan GT-R NISMO and a McLaren 650S Spider, although well off the pace of a McLaren 720S or a Lamborghini Huracán Performante.
“We went simple everywhere we could, and then the things that were complicated, we took them on as we had to, system by system.” Gardner and his team quickly realized they couldn’t make do with the stock 2.0-liter inline-four and continuously variable automatic transmission, so they swapped in a 2.4-liter inline-four (Toyota’s 2AZ-FE) and a five-speed manual (Toyota E-series), positioning the engine and gearbox as far back and as low as possible. It’s still a front-wheel-drive vehicle, though, like every C-HR Toyota sells in America.
The team tested six different turbocharger setups and settled on a unit from Garrett that routinely produces 23.0 psi of boost, fed by a four-inch intake. At full bore on racing fuel, the C-HR R-Tuned makes 600 horsepower and puts down 550 lb-ft of torque, we’re told. We won’t get to experience all that output, but that’s getting ahead of our story here.
Overcoming Hurdles
Its transformation didn’t come easily, mind you. Who could’ve guessed clearance issues in the pedal box would require DG-Spec to raise the car’s floor two inches? And when you replace the bulky OE exhaust with a three-inch cat-back system, you don’t expect issues. “We didn’t predict how much airflow would go up into the rear bumper cover when we went to a small, transversely mounted Burns muffler,” says Gardner. “We introduced all this void area. It wasn’t a problem until the car went 150 mph. At that point, we melted the whole freaking thing off.”
Gardner and his team also had problems with the massive rear wing, which is mounted to the C-HR’s hatch. It had little lateral rigidity and swayed in the wind, so DG-Spec affixed cross supports to firm up the structure. Then the hatch itself started to crack, so the team welded and installed some impressive bracing to offset the pressure. Complementing the wing is an adjustable carbon-fiber front splitter that helps the C-HR R-Tuned produce about 300 pounds of downforce at 120 mph and about 400 pounds at 150 mph, Gardner says. You’d not run into these issues if you settled for merely matching the performance of a 215-hp Nissan Juke NISMO RS, but all of these headaches emerge because someone at Toyota thought that this C-HR should perform on par with a Nissan GT-R.