Anyone who's had the pleasure of taking a cruise around town in a new SRT8 Challenger knows there is plenty of power and torque, especially from a small-block. With a quick look at the numbers-425 hp and 420 lb-ft-it's easy to see why they're so much fun to drive. But by looking at another number, the 4,132-pound curb weight, we can see where more power to motivate all that weight wouldn't hurt. We will do so by using the old-school mentality of upgrading to a bigger cam and better exhaust to deliver more power.
We start this project off with a moderately modified, manually shifted '09 SRT8. Under the power bulge hood we find a K&N intake. Owner of Coastal Dyno in Tampa, Florida, Sam Lippencott, and his head tech, Horacio Ramos, tied the behemoth to the rollers of his Mustang Dyno to give us a baseline of 395 rwhp and 381 lb-ft of torque.
To make these numbers a little more impressive and add some serious sound, car owner Aziz requested that Coastal install a nice group of parts. First on the agenda was improving the 6.1L Hemi's respiratory abilities. To do this, Coastal will be installing a set of stainless steel American Racing long tube headers with 17/8-inch primaries which converge at a 3-inch collector. From there, off-road 3-inch mid pipes remove the catalytic converters and reduce exhaust restriction (not smog legal). Behind the ARH exhaust, the factory exhaust with aftermarket mufflers will be replaced with a full-stainless system from Magnaflow that reuses the factory exhaust tips.
The American Racing Headers are made from stainless steel and feature merge collectors with velocity spikes. This design has its roots in racing and has been proven to make a few extra ponies-a very cool design feature.
With the Hemi's breathing increased, it makes the installation of the custom grind Comp Cam more effective. However, to accommodate the increased valve lift and duration, Comp beehive springs and pushrods will also be installed. This should make for smooth sailing and reliability. The specs on the cam are .547/.550-inch lift, and 224/228 degrees of duration on a 114 LSA, which should make for some nice sounds. Now follow along as we tear into this late-model Challenger and try to unlock more power and a set-to-kill idle.
Conclusion
The final results have proven the potential of these late-model Hemi engines for daily use and for serious power. "The car really woke up and I was surprised how much faster it felt. The seat of the pants indication has made the SRT8 an amazing driver. The idle through the new exhaust is equally as impressive and enough to put a smile on any Mopar fanatic. Why didn't they all come this way?" said Sam.
