More on that later. First, let’s take a look under the hood, which is distinguished by one real hood scoop and two fake breather vents. The starting point for the SRT4 engine was the same 2.4-liter Chrysler/Hyundai/Mitsubishi DOHC 16-valve aluminum four you can get with a Caliber, except the Caliber version generates 172 horsepower and 165 pound-feet of torque. This one, as you already know, generates a helluva lot more. Here’s how. The pistons are cast aluminum, running in iron liners, with forged con rods and trimetal bearings. SRT was confident the standard forged-steel production crank could take the extra heat and power. Oil squirters help keep the pistons cool, and an external cooler keeps temps of the Mobil 1 synthetic oil uniform.
At the top end, there’s variable valve timing on both cam banks, with bucket tappets punching the valves, which are made of Inconel (a high-temp alloy) on the exhaust side. And, of course, there’s that most essential of ingredients—boost, 12-psi max at sea level, but it can rise to 15 psi at high altitudes, provided by a Mitsubishi TD04 turbocharger via a big (11-row) Valeo air-to-air intercooler. Like the previous SRT4 engine, this 2.4 is a long-stroke design and not a high-revver. The power peaks are more like lofty plateaus. Max torque is available from 2000 to 5600 rpm, max horsepower is on tap from 5700 to 6400, and the small-scroll turbo spools up quickly.
The engine feeds its output into a six-speed Getrag manual gearbox via a dual-mass flywheel. Like the gearbox in the garden-variety Caliber, it’s a cable shifter, but the throws are shorter and the engagements are far more decisive.
There are cosmetic elements to the SRT package, too, but we think you’d rather hear about the dynamic payoff first. Okay. Let’s start with the what’ll-she-do department. Getting an effective launch is tricky, something that’s true of most front-drive turbo cars. The SRT people predict 0-to-60 mph in a little over six seconds. We clocked 5.9. The quarter-mile ate up 14.4 seconds, showing a 103-mph trap speed. Top speed is officially listed as 155 mph, although one of the SRT development guys says he ran a prototype to as high as 161.
At the top end, there’s variable valve timing on both cam banks, with bucket tappets punching the valves, which are made of Inconel (a high-temp alloy) on the exhaust side. And, of course, there’s that most essential of ingredients—boost, 12-psi max at sea level, but it can rise to 15 psi at high altitudes, provided by a Mitsubishi TD04 turbocharger via a big (11-row) Valeo air-to-air intercooler. Like the previous SRT4 engine, this 2.4 is a long-stroke design and not a high-revver. The power peaks are more like lofty plateaus. Max torque is available from 2000 to 5600 rpm, max horsepower is on tap from 5700 to 6400, and the small-scroll turbo spools up quickly.
The engine feeds its output into a six-speed Getrag manual gearbox via a dual-mass flywheel. Like the gearbox in the garden-variety Caliber, it’s a cable shifter, but the throws are shorter and the engagements are far more decisive.
There are cosmetic elements to the SRT package, too, but we think you’d rather hear about the dynamic payoff first. Okay. Let’s start with the what’ll-she-do department. Getting an effective launch is tricky, something that’s true of most front-drive turbo cars. The SRT people predict 0-to-60 mph in a little over six seconds. We clocked 5.9. The quarter-mile ate up 14.4 seconds, showing a 103-mph trap speed. Top speed is officially listed as 155 mph, although one of the SRT development guys says he ran a prototype to as high as 161.