It’s faster than a revved up Porsche Cayenne Turbo. It laughs in the face of a BMW X5 and accelerates to 60mph faster than a new Mustang GT. The new supercar, Jeep’s rowdy Grand Cherokee SRT8, is equipped with a powerful 6.1-liter Hemi V8, making 420 horsepower and 420 pound-feet of torque. This SUV family truck is definitely not your average SUV and you’ll know it soon enough once you hear its raucous roar as you hit a quarter mile in a matter of 13.5 seconds, which is just muscle car territory by the way.
Despite the power delivered by Jeep’s Grand Cherokee SRT8, it still doesn’t match the performance of the Dodge Viper SRT10 Coupe, and for this very reason, Hennessey Performance created the new SRT600 package. Hennessey Performance was the same person responsible for tuning the Viper and since he wants to always create something more powerful than his previous masterpiece, he has developed the performance package that will allow the Grand Cherokee SRT8 to finally defeat the ferocious Dodge V10 Viper in a Sprint from 0 to 60 and a quarter mile.
This has actually already been achieved with the new fortified Jeep Hennessey SRT600, the Viper being bested to 60mph by half a second and crossing the quarter-mile finish line two-tenths ahead of a much shorter and lighter Viper.
Ever wonder where Jeep’s added Saturn V-like oomph comes from? Instead of a solid rocket booster, a big Garrett turbocharger has provided the boost to a modified 6.1-liter V8. How did Hennessey Performance achieve this? They first started by removing the original SRT8 V8 and stripping it down to the cast iron cylinder block. Later, heavy-duty bearings were added before the installation of aftermarket forged steel connecting rods, 9.5:1 forged aluminum piston and high-performance piston rings.
Hennessey also modified the cylinder heads by creating a full port on the intake and exhaust runners along with polished combustion chambers. And on the airflow test bench conducted by Hennessey, the ported heads flow 360 cfm at each intake port, which is about 60 cfm more than stock.
To further increase airflow to the cylinders, a single Garrett T4 turbocharger was added that provides seven psi of boost. Custom stainless steel headers deliver the exhaust to the turbo, then boost is fed through polished stainless steel 3.5-inch piping, a large front-mount aluminum air-to-air intercooler and intake pipe. stacked with twin billet aluminum blowers. off the valves. Keeping turbo boost in check is a single 44mm wastegate, while the 180-degree thermostat helps the Hemi stay cool.
Hennessey has also added a high volume fuel pump that provides a continuous flow of gasoline; likewise, oversized fuel injectors and a special fuel pressure regulator are being monitored by a custom-programmed engine computer. The result of all these processes is a 6.1-liter V8 that delivers 600 horsepower at 5,200 rpm backed by 650 pound-feet of torque at 4,000 rpm. Such powerful torque requires a lot of airflow from the engine that prompted the Hennessey to install a three-inch-diameter stainless steel dual exhaust system, high-flow mufflers, and four-inch-diameter polished exhaust tips. At idle, the SRT600 is like a tame lamb, but try to put the throttle down and it wakes up a monstrous beast. A word of caution: The Hennessey SRT600 Jeep SRT8 is not for the faint of heart.
Modifications made to the Jeep SRT8 were kept to a minimum, which means that, aside from the engine, basic SRT8 components such as the Jeep fuel filter, factory SRT-spec Brembo disc brakes and many more remained unchanged. However, the exterior was upgraded by adding some SRT600 badging and optional 20×10.5-inch forged aluminum wheels wrapped in 295/30ZR20 Michelin Pilot Sport 2 tires.
