New York show: Chrysler unleashes SRT8 super-twins

CHRYSLER has taken the wraps off two highly anticipated new high-performance SRT8 models at this week’s New York auto show, confirming a stonking 6.4-litre Hemi V8 for the Jeep Grand Cherokee and the forthcoming redesigned 300C – both of which are heading Down Under.

Chrysler Australia has told GoAuto that both SRT8 variants are certain starters for Australia, with the Grand Cherokee SRT to sit atop the recently released fourth-generation SUV series from early next year and the 300 SRT to join the all-new large car range now due around mid-2012.

The US rollout begins with the Grand Cherokee SRT in the third quarter of this year.

“We’re all incredibly excited by the unveiling of the SRT8 range, and can confirm they will indeed make it to Australia,” said Chrysler Australia spokesman Dean Bonthorne.

“The Grand Cherokee SRT8 will join the rest of the range around Q2, with 300C SRT8 not until mid-year or early Q3.”

As expected, the Fiat-controlled US auto giant has increased the displacement size of its bent eight SRT from 6.1 to 6.4 litres, and although full details are still to be revealed, Chrysler has announced that the new engine will deliver an “estimated” and neatly rounded 465 horsepower (347kW) and 465 lb-ft (630Nm).

This makes the Grand Cherokee the most powerful production Jeep in history, and likewise the 300C becomes Chrysler’s most powerful sedan ever, with preliminary performance figures – using the standard five-speed automatic transmission – pointing to 0-60mph (96.56km/h) completed in 4.8 seconds for the SUV and “in the high four-second range” for the sedan.

The quarter mile for the Jeep should be dispatched in 13.5 seconds on its way to a 250km/h top speed, while the 300 is claimed to pass the same (402m) mark in the “high 12-second range” and continue on to just over 280km/h.

From top: Jeep Grand Cherokee SRT8 engine, Chrysler 300C SRT8, Chrysler 200C S convertible and sedan.

By comparison, the previous SRT8’s 6.1-litre Hemi V8 produced 317kW at 6000rpm (detuned slightly in the Jeep to 313kW) and 569Nm at 4600rpm, while the new Grand Cherokee’s range-topping circa-$70,000 5.7-litre Hemi delivers 259kW and 520Nm.

Running on premium unleaded petrol, the previous SRT8s were relatively thirsty beasts, consuming 14.2L/100km in the 300C and 16.1L/100km in the Grand Cherokee, while CO2 emissions were at 337 and 380g/km for the sedan and SUV respectively. The 5.7 Grand Cherokee, meanwhile, returns 14.1L/100km and 224g/km.

Chrysler is still to provide official economy and emissions figures for the new-generation SRT8 models, but has foreshadowed a 25 per cent drop in highway-cycle consumption with the introduction of a new ‘active valve’ exhaust system that allows the cylinder-deactivation system to engage over a wider rpm range when in four-cylinder mode.

The new exhaust system is also said to allow for ‘straight-through’ mid and rear mufflers for a rortier exhaust note under engine load.

Chrysler claims the substantial 61Nm increase in pulling power allows for “inspired standing starts and improved straight-line performance” while new performance-tuned engine mounts aim to improve idle stability and ride control at any speed when on the move.

An ‘active’ intake manifold and high-lift camshaft with cam phasing are said to contribute to improved low-end torque and high-end power, with 90 per cent of peak torque now available between 2800 and 6000rpm.

Stopping power is also impressive on the new SRT8s courtesy of upgraded Brembo braking hardware, with the SRT8 Jeep slowing from 60mph to standstill in 35.4m and the flagship Chrysler sedan completing the task in 36.6m.

Both models use six-piston front and four-piston rear callipers (painted red in the Jeep, silver on the Chrysler) and large ventilated discs at all four corners – 381mm diameter up front on the SUV and 361mm for the sedan, and 350mm at the rear for both vehicles.

Understood to be benchmarked against BMW’s X6 M for both engine performance and chassis dynamics, the Street and Racing Technology (SRT) Grand Cherokee is described as the best-handling Jeep ever – the hot 300 comes with similar billing – with Chrysler pointing to a .90g capability on the skid pan and a new SRT-tuned adaptive damping system managed by the ‘Selec-Track’ system.

While all Grand Cherokee model variants in Australia have a ‘Selec-Terrain’ traction control system that allows the driver choose between snow, sport, auto, sand/mud and rock modes, the SRT includes a number of specific dynamic modes, including sport and track.

Drivers are also handed steering-mounted gearshift paddles, while the fully hydraulic steering system is performance-tuned, includes a new heavy-duty pump and pump cooler, and revised gearing is said to elicit a more direct feel and on-centre response.

The SRT8 Grand Cherokee rides on new split five-spoke 20-inch forged alloy wheels and 295/45 Z-rated Pirelli PZero run-flat tyres.

Sitting 25mm lower to the ground compared to other Grand Cherokees, the SRT8 flagship is also easily recognised as the performance leader of the pack with new SRT-exclusive body-coloured flared wheelarches and side sill cladding, LED daytime running lights, body-coloured grille with black screen background and chrome bezel inserts, a menacing black lower airdam and a newly sculpted bonnet with dual black heat extractors.

The performance theme is seen at the rear with a new aerodynamically honed upper spoiler and lower air diffuser, along with a dual exhaust system with four-inch outlets.

Inside, there are a host of racing-themed and SRT-exclusive items, such as a heated, leather-wrapped and flat-bottomed steering wheel, SRT-styled sports Nappa leather/suede heated and ventilated front seats, carbon-fibre trim, an 825W 19-speaker Harman Kardon stereo (including 10-inch subwoofer) and specific SRT trip computer pages that show steering input measurements, horsepower, torque, acceleration times, braking distances, g-forces and other “expanded engine information”.

Much of the same applies to the car Chrysler dubs its “300 street machine” – adaptive damping, lowered sports-tuned suspension, Brembo brakes, 20-inch wheels, aggressive exterior package, premium audio, exclusive interior environment, and so on.

Chrysler also used the New York show to unveil S-branded versions of both the 300 and its 200 medium-sized range, the latter still to be confirmed for release in Australia due to the current production restriction to left-hand drive.

Chrysler Australia has advised that it is still too early to tell whether it will be given the opportunity to introduce the 300 S, which at this stage is restricted to the US market.

These include SRT-style features such as 20-inch wheels, body-coloured fascia accents, blackened headlamp bezels, ‘touring-tuned’ suspension, sharper steering, unique black and red leather trim options and, according to Chrysler, the “world’s first integration of Beats by Dr Dre audio technology – the best standard audio system, period”.

The S-branded 200 sedan and convertible are slightly tamer by comparison but aims to provide “a little more style and elegance in a segment traditionally known for its sea of sameness”.

It also has a healthy dose of performance Chrysler’s 3.6-litre Pentastar V6 engine fitted standard, and sportier handling with a comprehensive overhaul to the suspension.

Exterior features include a unique front grille, black headlamp accents and 18-inch alloy wheels with dark-painted pockets and ‘S’ badging, while the interior includes S-branded heated leather front seats (with suede inserts), suede door trim, black headlining, a perforated leather steering wheel and a premium Boston Acoustic sound system with high-grade plug and play capabilities.