Dodge SRT-4


 * More information is available on the Dodge Neon page. See also the Dodge Caliber SRT-4.

The Dodge SRT-4 was a turbocharged compact car introduced by DaimlerChrysler's Street and Racing Technology (SRT) in-house tuner group (originally known as PVO)in 2003. SRT stands for "Street and Racing Technology", and the "4" in the SRT-4's name denotes the number of cylinders it has. ACR and Commemorative Edition models were later introduced as well. The SRT-4 was designed for the racing and muscle car crowd, as well to attract younger buyers who had previously only considered owning Japanese sport compact cars.

The SRT-4 differed from a Neon, the model on which it was based, in many ways. From the outside, the SRT-4's unique front fascia was immediately noticeable. It also featured a large rear wing, unique rear fascia, side skirts, unique hood featuring a functional hood scoop, and special 17x6 in wheels (16x7 on ACR model). Beyond aesthetics, the SRT-4's entire power train, suspension, braking system, exhaust, and much of the interior differed from the Neon of which it was based on.

Under the hood was a turbocharged 2.4 liter I4 engine. This engine first appeared in the United States one year earlier in the 2002 Chrysler PT Cruiser GT Turbo, but had been used in the Mexican-market Dodge Stratus/Chrysler Cirrus LXi sedan for a few years before this. The SRT-4 used a New Venture Gear T-850 5-speed manual transmission (pirated from the Graz-built turbo diesel minivan), equal-length half shafts, and a high-capacity Sachs performance clutch. The suspension used stiffer springs, special Tokico struts, larger sway bars front and rear, firmer bushings, an upgraded steering rack from the PT Cruiser GT, upgraded knuckles, and a unique K-member. 11.0 in (279 mm) vented disc brakes (with extra-thick rotors to prevent warping) were used in front, with 10.6 in (270 mm) non-vented discs in the rear.

Inside, the front seats featured enhanced lumbar and lateral support for performance driving, and a faux carbon fiber steering wheel and satin silver "cue ball" shift knob were used. The gauges had special SRT faces and silver rings matching those on the climate controls. An Auto-Meter brand boost gauge was used as well.

The 2004 model was updated with more power and torque, a torque-sensing Quaife limited-slip differential, larger fuel injectors, BF Goodrich KDW2 three-season, ultra-high performance tires, and paint and trim changes. 2005 also featured new colors, but the important news was the return of the American Club Racing (ACR) edition. This package included wider BBS RX lightweight racing wheels with wider tires, 5-way adjustable Tokico Illumina shock absorbers, a stiffened suspension featuring thicker front and rear sway bars, seats with pass-through slots for racing harness's, factory service manual-allowed camber adjustment, and ACR logos on the exterior and embroidered on the front seats. A limited edition, numbered, 2005 SRT-4 Commemorative Edition appearance package (in white with blue "Viper stripes") was also offered, but not with the ACR package.

Performance and Specifications

 * Curb weight: 2880 lb
 * Power: 215 WHP (2003 model), 230 WHP (2004-05 models).
 * Torque: 245 ft·lbf @3000 rpm (2003 model), 250 ft·lbf @2200 rpm (2004-05 models)
 * 0-60 time: 5.3 seconds (Car & Driver)
 * 1/4 mile time: 13.8-14.2 seconds (various magazine reviews)
 * 1/4 mile speed: 98-102 mph (various magazine reviews)
 * Top Speed: 153 mph

Although the SRT-4 is rated at 230 hp (2004+), it was revealed that Dodge underrated the car's power production. Dodge tested the SRT-4 prototypes on the dyno with a fairly hot intercooler, which negatively affected overall efficiency. Most production SRT-4s in fact rate right around 230 hp at the wheels, therefore crank horsepower is estimated at 265-275 hp. This makes them fairly formidable versus much more expensive production sports cars in real world, "roll-on" situations from 30 mph and up.

When Dodge was re-designing the SRT-4 pre-production model in late 2002 prior to its release, they added two nostrils on the front fascia to help with the upgraded cooling system, a revised boost gauge face, and standard pedals instead of the aluminum ones that would be used on later year's SRT-4's.

Engine block
 * Engine code: A855
 * Block construction: Cast iron, closed deck, split crankcase
 * Bore x stroke: 87.5 mm x 101.0 mm
 * Displacement: 2,429 cc
 * Compression ratio: 8.1:1
 * Bore spacing: 96 mm
 * Deck height: 238.14 mm
 * Pistons: Cast by Mahle, eutectic aluminum alloy
 * Connecting rod design: Forged, cracked caps, threaded-in 9 mm rod bolts
 * Connecting rod length: 151 mm
 * Rod/stroke ratio: 1.50:1
 * Crank design: Cast high-hardness steel
 * Main bearing diameter: 60 mm
 * Rod bearing diameter: 50 mm

Cylinder Head
 * Head construction: Cast aluminum
 * Combustion chamber design: 48-degree pent-roof with partial cloverleaf between intake valves
 * Valvetrain: Hydraulically adjusted rocker arm with roller cam followers
 * Intake valve size: 34.80 mm (Silchrome-1)
 * Exhaust valve size: 28.45 mm (Inconel)
 * Intake valve angle: 24.46 degrees
 * Exhaust valve angle: 23.5 degrees

The SRT-4 used the same block and head as the turbo PT Cruiser; however the intake manifold, turbo plumbing and intercooler are different. The intercooler is a front mounted cast aluminum 8-row unit produced by Valeo. The turbocharger is a reverse rotation Mitsubishi TD04LR-16Gk with a 6 cm&sup2; turbine inlet. Tight packaging forced some creative thinking on the turbo. The TD04 compressor has a compressor bypass valve built right into the compressor housing. The exhaust manifold and turbine housing are cast in one piece by Mitsubishi from high-nickel Ni-Resist steel. The one-piece design improves flow, reduces size and reduces thermal mass for quicker cat light-off. The turbine discharge is also part of the manifold/turbine housing casting, and it loops back around and hits the manifold again on its way to the catalytic converter. Where they meet, there's a wastegate valve. Keeping the wastegate valve away from the turbine housing improves flow where it matters most. Maximum boost in stock form is around 14 lbf/in&sup2; (97 kPa). This translates to 215 hp @ 5400 rpm and 245 ft·lbf torque @ 2000 rpm at the flywheel ( 2004-05 230 hp and 250 ft·lbf (339 Nm) torque now boosting 15 lbf/in&sup2; (103 kPa))Dodge under estimated these power figures as it has been proven on many occasions that these numbers are usually seen at the wheels.

Exhaust fumes exit through a catalytic converter, two resonators and a stainless steel mandrel bent 2.25 inch exhaust piping system, which splits into two at the rear with no mufflers, for a distinct sound.

Paired with the SRT-4’s turbo-charged power plant are a New Venture Gear (NVG) T-850 high-performance 5-speed manual transmission, equal-length half shafts and a Sachs high-capacity performance clutch and pressure plate.

Suspension is rounded up with 170 lb F / 125 lb R springs, specially valved Tokico struts, 24 mm front / 17 mm rear sway bars (Larger sway bars are available through Dodge parts. a 26 mm bar for the PT cruiser convertible and a 19 mm rear bar from the Neon ACR can be ordered, and is standard on the SRT-4 ACR), firmer bushings, quicker ratio steering rack from the PT GT, upgraded knuckles and a unique K-member.

Blending power and control was made possible by the interaction between the Dodge SRT-4 development team and performance operation engineers who cut their teeth in Sports Car Club of America (SCCA) racing. Braking consists of an ABS system with 11.0 in (279 mm) F vented/ 10.6 in (270 mm) R discs and single piston calipers (57 mm F/ 36 mm R).

17x6.0 (45 mm offset) cast aluminum wheels coupled with 205/50/17 Michelin Pilot Sport tires help put the power to the ground on 2003 models, with 2004+ models getting BF Goodrich KDW2 tires. Even wider 225/45/16 BF Goodrich KDW2 tires on lightweight BBS racing wheels (40 mm offset) were offered on the ACR model in 2005. The expressive standard 17x6 wheels were purposely designed to look like aftermarket wheels, and the unique spoke pattern allows for better airflow to the brakes. The design shows much similarity to the TSW VX1 wheels found on the 2001 concept supercharged Neon S-R/T.

On the outside, performance cues start up front where a new front fascia and a unique steel hood with an integral air intake that perches, ready to cool the powerful 2.4-liter turbo engine. Just behind the lower grille sits a cast aluminum intercooler. The taller, basket-handle type spoiler also improves vehicle handling by generating downforce and providing a stabilizing effect at high speeds.

Inside the cabin, taking cues from the seats in the Dodge Viper SRT-10, the SRT-4 front seats have enhanced lumbar and lateral sections for better support during racing-type maneuvers. The new Agate-colored cloth on the body of the seats is textured for better grip through the corners. The side bolsters of the front seats are trimmed in vinyl and curve to stabilize occupants, further enhancing the performance racing feel of the vehicle. The car's rear seats also feature the textured fabric.

A new carbon-fiber-look leather wraps the top of the SRT-4’s steering wheel for greater control. A satin silver cue ball shift knob tops a shifter that is surrounded by a boot made of the same textured carbon-fiber-look leather as the steering wheel. The steering wheel's unique three-spoke design also provides a better view of the instrument cluster gauges.

Unique gauge designs in the SRT-4 (which are exclusive to the SRT lineup) feature special silver faces with satin silver ring accents. The same satin metal trim also is featured on the instrument panel center stack, around heater, ventilation and air conditioning (HVAC) knobs and on door handles. A silver Auto-Meter brand turbo boost/vacuum gauge is to the right of the instrument cluster. The temperature gauge also plays an active role in monitoring the cars vitals. It is very functional piece unlike most other modern cars in which the temp. needle never moves, staying in the middle of the range while coolant temperature rises and falls as much as 40 degrees. However in the SRT-4, drive fast and the needle climbs, cruise and it falls.

Along those lines, the SRT-4's boost/vacuum gauge finds a convenient spot underneath the brow just to the right of the instrument cluster. Unlike aftermarket gauges, the SRT-4 turbo gauge has been thoughtfully incorporated as a design element of the brow.

The SRT-4’s roots come from SCCA racing. Dodge intended a package of performance, styling and quality at a low cost, and has shown what the SRT-4 is capable of in motorsports, campaigning the SRT-4 in Rally, SCCA and drag racing circuits, with much success.

The 2004 model received some much needed enhancements which included the following below.


 * New torque-sensing limited-slip differential developed jointly with Quaife
 * Power increased to 230 hp (172 kW) at 5300 rpm and torque increased to 250 ft·lbf (339 Nm) between 2200 and 4400 rpm
 * New NGC3 engine control module and a new calibration for wider torque range
 * Mopar Stage 1 Larger fuel injectors provide increased fuel flow
 * New BF Goodrich KDW2 three-season tires are standard equipment
 * Developed to match the vehicle’s high-performance suspension and handling characteristics, the new tire’s design and rubber compound provide maximum grip for cornering, accelerating and braking
 * Unique racing-inspired bright pedal pads added
 * Optional sunroof with passenger assist handles
 * Electric Blue paint replaces Solar Yellow
 * Chrome trim replaces the black trim on the headlamps

The 2005 model received a few new colors - Orange Blast which replaced Electric Blue, and Stone White which replaced Bright Silver Metallic halfway through the 2005 The return of the ACR name plate in 2005, with the package available only on the SRT-4, included:


 * 16x7 BBS RX light-weight wheels with 40 mm offset
 * 225/45/16 BFG KDW2 tires
 * one inch lower ride height
 * 5-way adjustable Tokico Illumina dampers
 * Thicker front and rear sway bars
 * Stiffer rear tension strut bushing
 * ACR embroidered Viper inspired seats with Viper racing harness slots
 * ACR decals on the bottom of the front doors
 * Full-size spare with accompanying ultra-high performance tire
 * There were a total of 1,175 SRT-4 ACR’s produced: 225 red, 211 tangerine, 306 white, 433 black.

Also for 2005 was the SRT-4 Commemorative Edition. This model (along with the SRT-10 Viper and Ram) was created to celebrate the excitement, power and performance that SRT vehicles bring to the road. The limited edition SRT-4 included the extra appearance options below. (No performance extras are added on the Commemorative Edition):


 * Electric Blue "dual fang" racing stripes over the Stone White body color
 * Blue accent stitching on the seats, floor mats, shift boot and steering wheel
 * Stainless steel door sill plate
 * Commemorative Edition Production Number