2006 Chrysler 300C SRT8 Preview

So what is responsible for the surge in engine output? Obviously much is gained by upping the HEMI's displacement from 5.7- to

When production versions hit the test track, expect the SRT8 to break into the high 4-second range in sprints from 0 to 100 km/h. (Photo: DaimlerChrysler Canada)

6.1-liters, a task that included boring out the cylinder diameters by 3.5 millimeters apiece. To strengthen the modified block, the SRT engineers added reinforcements and while they were at it, increased coolant flow. A forged steel crankshaft was used to minimize vibration, while stronger powder-metal connecting rods capped off by oil squirter-cooled floating-pin pistons were attached. Underneath, a modified oil pan is said to reduce oil foaming.

To up engine speed and effectively increase horsepower the SRT techs modified the cams, increasing revs by 15 percent to almost 6,200 rpm - the current 5.7-liter HEMI tops out at 5,400 rpm. The engine's hollowed out valve stems also reduce drag due to their lighter weight. Interestingly, the hollows are filled with sodium for dissipating heat more effectively.

Like an athlete, an engine will perform better if it can breathe easier. To achieve this result SRT engineers added new

Engine exhaust will leave the back of the car via new larger diameter tailpipes finished off with two fat 3.5-inch chrome tips. (Photo: DaimlerChrysler Canada)

high-flow cylinder heads, with larger diameter valves combined with reshaped cylinder ports, and a redesigned intake manifold with larger diameter runners for higher-speed tuning. The result of the SRT division's work is quicker turning, much more powerful engine featuring a compression ratio that increases from 9.6:1 to 10.3:1.

Finally, seriously "hot" exhaust headers that feature "individual tubes encased in a stainless steel shell" were added, or so says Chrysler. Engine exhaust will leave the back of the car via new larger diameter, 2.75-inch compared to 2.5-inch, tailpipes finished off with two fat 3.5-inch chrome tips.