's little retro wagon, the HHR, has been given the SS treatment, with a turbocharged engine and a firmed-up chassis, plus some tuner-style body modifications and interior upgrades. The resulting car may be a little hard to take seriously, but at least there's now a lot more substance beneath the HHR's candy-coated shell.
That shell, with its pleasingly rounded styling and practical wagon layout, has been netting the HHR 100,000 sales per annum, but the Cobalt mechanicals underneath mean that those buyers are unlikely to be driving enthusiasts. Now General Motors' in-house tuner crew has imbued the HHR with newfound power and poise.
The HHR SS benefits from the latest thinking at the GM Performance Division. That means turbocharging rather than supercharging for the 2.0-liter four, which also is treated to direct injection. The benefits are twofold. First, the turbocharged engine meets 2008 emissions standards that the supercharged 2.0-liter could not. (Which explains why the Cobalt SS Supercharged has disappeared from the lineup.) Second, the 2.0 turbo makes a lot more power: 260 hp versus 205 hp, and 260 lb-ft of torque versus 200 lb-ft.
To get all 260 ponies, you need to opt for the manual transmission; the engine in the automatic-equipped car is detuned to 235 hp, in deference to the four-speed automatic's fragility. For the SS, Chevrolet has shortened the manual's shift throws and moved the shifter both forward and up so it isn't such a far reach. Unfortunately, the five-speed's shift action is pretty notchy. Chevrolet quotes 0-to-60-mph times of 6.3 seconds for the manual and 7.5 for the automatic, but the gulf between them feels greater. Whereas the 235-hp car feels responsive but nothing more, the stick-shift SS is fast; the car doesn't shoot out of the hole, but its acceleration swells as if on a wave. Stay with it, and it will carry you all the way to 150 mph. The turbo's power delivery doesn't really lag, but it does build, with a faint, telltale whistle in the background. Mostly, though, what you hear is the cacophonous noise of the direct-injection engine, with some gearbox whine tossed in. You won't mistake it for a Honda VTEC engine.
When we say that the HHR SS doesn't blast away from a stop, we should qualify that statement by explaining that this is without using launch control. Yes, just like the Porsche 911 GT2, the HHR SS has a launch control mode. Switch the traction control to the competition setting, and the car is ready for launch control at any stop. Floor the throttle and the engine holds 4100 rpm, so the turbo is spooled up when you release the clutch. The result isn't a smooth launch - in fact, it feels like you're going to snap a half shaft - but it is a quick one.
Chevy also makes much of the "no-lift shift" feature in the HHR SS. The engine-management software's programming allows you to keep the accelerator planted during upshifts. The revs rise to 6200 rpm - just shy of the 6350-rpm redline - and turbo boost doesn't drop during shifts (as you can see by checking the A-pillar-mounted boost gauge). Again, this is mostly a parlor trick to impress your friends - particularly those who will thrill to the exhaust backfire that accompanies each shift.
More so than managing engine revs, a front-wheel-drive car with 260 lb-ft of torque needs to manage torque steer. Here, Chevy has done a better job than you might expect, particularly if you've driven a supercharged Cobalt SS or the HHR's closest domestic competitor, the Dodge Caliber SRT4. Chevy engineers point to the revised roll-center height, new steering knuckles, and different antiroll-bar mounting points, which they claim help exorcise the front-wheel-drive demons. When pulling out of slow, tight corners, torque steer never raised its squirmy head on dry pavement. We also took a turn in the 235-hp car in the rain, during which we did feel tugging at the wheel, but the car didn't dart off in all directions. In all, it was a commendable performance.
In fact, the chassis tuning overall is very well done. The HHR SS gets firmer springs, dampers, and antiroll bars, which keep body lean in check. The 225/45R-18 Michelin Pilots really hang on, and the recalibrated and quickened electric power steering does a convincing impression of a hydraulic system. We'd only wish for a bit more rebound damping, as cresting a sudden rise causes the HHR SS to momentarily lose its composure. In the spring, Chevrolet will offer a further chassis upgrade in the form of Brembo front brakes with larger rotors packaged with a limited-slip differential.
The mechanical enhancements to the HHR SS have been successful, but we're not totally down with the cosmetic changes. We like the eighteen-inch wheels, but the new fascia gives the car a nose-heavy, front-wheel-drive look, and the flared lower body cladding seems out of place and is annoying to step over. Inside, there are nice, suede-like inserts on the seats, but only the driver gets the more supportive, sport bucket seat (the non-matching, standard-style passenger seat preserves the fold-flat function). There's also the aforementioned boost gauge and a smaller-diameter steering wheel.
The HHR might seem to be an odd car to get hot-rodded, but the work is certainly well done. This pint-size son of yesteryear's Suburban can now take you into the past faster than ever before.
Turbocharging has replaced supercharging as the preferred horsepower helper for GM's Ecotec four. The direct-injected, 2.0-liter turbo debuted in the Pontiac Solstice GXP (followed by the Saturn Sky Red Line). There are lots more cars to come:
HHR SS Panel
Cobalt SS Turbocharged sedan