Everything you wanted to know or didn't want to know about the SRT-4 *VERY LONG*

[evo77]

Birth of the concept Neon SRT
In 1998, Tom Gale (then Executive Vice President-Product Development and Design for Chrysler) assigned a specific project to a team of engineers. The assignment objectives were to develop a Neon with a list of performance features based on the sport compact cars that Tom had seen at the 1998 Specialty Equipment Manufacturers Association (SEMA) Show in Las Vegas.

The three-man team of engineers consisted of Marc McCammon-project manager, Marc Musial-powertrain engineer and Dave Chyz-mechanic (one of the youngest technicians to work on the original Dodge Viper). The team members shared first-hand experience in one form or another with the existing Dodge Neon.

"Mark brought his experience with turbos and superchargers," recalls McCammon. "And Dave threw in his engine expertise, and before you knew it, we had built a car from scratch in just four months."

Often, that meant putting in long hours after they officially punched out from their "day jobs." Between the three of them, the group logged more than 1,000 test track miles after hours in less than two weeks. By November 1999, Gale had his car, and it had a spot on that year's SEMA show floor. Based on the positive response there, Gale decided to put the black vehicle, (then badged the Neon SRT), center stage on the concept car turntable at the Los Angeles Auto Show the following January.



The original concept Neon SRT specs were a 2.0 liter SOHC 16-valve four cylinder topped with a 45-cubic inch Eaton supercharger, which produced 208 hp and 180 lb-ft of torque at the flywheel on 11 psi of boost. (Sport Compact Car magazine tested the car in the Feb. 2001 issue and dynoed 179 hp and 149 lb-ft tq at the wheels.)

Tapped from the DaimlerChrysler parts bin was the engine block, a 1998 California emissions-spec block. Designed to pass the stringent TLEV emissions standards, this particular block had a lower, 9.3:1 compression ratio rather than the standard 9.8:1. That compression ratio was later lowered to 8.5:1 after extensive dyno testing showed the original compression to be to high for the amount of boost the car was running. A 2001 Neon R/T cylinder head was used to take advantage of the engine’s larger exhaust ports and its higher-lift, longer duration camshaft. The R/T's tubular steel header was used, as well as the catalyst and exhaust system. The only part of the exhaust not from the parts bin was the Borla muffler.

The Eaton Roots-style supercharger is usually bolted directly to the intake manifold, where its odd-shaped discharge port can simply blow into the middle of the plenum. In the Neon SRT, the supercharger is mounted directly below the plenum, but instead of blowing up into it, it blows down into a collector pipe, around the front of the supercharger and back into the manifold. This design allows the manifold to retain a more conventional shape with air coming in one side of the plenum and four, equal-length runners running to each port. This design, it turns out, evens the cylinder-to-cylinder air distribution, ensuring a consistent air/fuel ratio and consequently better performance. The supercharger plumbing also allows the possibility of an intercooler. With boost turned up to 11 psi, the little 45-cubic inch blower is pumping its heart out. Discharge temps reach as high as 300 degrees. Marc Musial-engine developer, did some testing with an intercooler and found that it dropped peak temperatures by 150 degrees which bumped up power figures to 230 hp. However in high hopes that the concept would become a reality, this was left out to keep costs down.

Power was put to the ground using a 5-speed T350 transaxle adapted from the PT Cruiser. Though dimensionally identical to the Neon tranny, the heavier, torquier PT gets stronger gears and a higher rated torque capacity. The Neon normally has a short drivers side axle and a long passengers side axle, but with the added torque of the super-charged engine, these unequal-length half-shafts would contribute to torque steer. Equal-length half-shafts require a jackshaft to carry drive from the differential to the passengers side inner CV joint somewhere behind the engine. The jackshaft was pilfered from the turbocharged 2.4 liter Stratus sold in Mexico, while the shorter drivers side axle from a Neon R/T was used on both the right and the left. Clutch assembly was provided from a Mercedes diesel. Completing the driveline were a Torsen limited-slip differential, low 3.94:1 axle ratio, and a street-friendly, overdrive fifth gear.

Styling was provided by Eric Stoddard-Designer, who came up with the design after blending what he saw as popular trends in the aftermarket. The bodywork was all fabricated in-house with the hood, front bumper and spoiler being a carbon fiber and Kevlar composite. The rear bumper was made of an unusual carbon fiber and rubber composite.

Eibach springs and Tokico shocks helped drop the SRT 1.5 inches lower than a standard Neon. Grip was optimized courtesy of sticky 205/40VR17 Yokohama A520 tires mounted on 7.0-inch-wide TSW VX1 aluminum wheels, while the SRT's four-wheel disc brakes feature vented, cross-drilled rotors up front. Other goodies include MOMO seats, white-faced gauges, thicker sway bars at both ends and an ear-splitting Alpine/JBL/Infinity sound system.



"When we heard Gale say, 'We need to make a production version in a brighter color,' we thought we were home-free," recounts McCammon.

But taking a concept car to the level of a production vehicle proved a test of the young team's mettle. Finding an approved engine, financing tooling, and keeping the price low enough to appeal to tuners like themselves presented new challenges to the neophyte group. At the same time, they also were secretly piecing together a second car using production-oriented parts and a design more adaptable to the existing Neon platform, all in the hopes of winning production approval for their dream car.

"Once we had the second car built, we snuck it into Tom Gale's parking spot in the executive garage one night, just to get it noticed," says McCammon. "We figured he couldn't possibly ignore his own ride home."

Despite the effort, the Executive Committee rejected the production car proposal when the team appeared before it in the fall of 2000. So, for the second time, McCammon got another list - this one full of reasons why the car wouldn't fly. But even that didn't deter the team.

"We literally went to every lead engineer, item by item, and asked them to explain why the item couldn't be done or offer a solution to fix it," says McCammon. "We just kept going until there was nothing left on the list."

Three revisions of the car later (including replacing the supercharger with a turbocharger), responsibility for the still unapproved project was transferred to the company's Specialty Vehicle Engineering (SVE) team, or as it would come to be known, Performance Vehicle Operations (PVO). In the spring of 2001, the plan once again was placed before the Executive Committee, and this time, it got the green light.

As an approved project, responsibility for the newly christened Dodge SRT-4 production car fell in the race-steady hands of John Fernandez, Director of Performance Vehicle Operations, who had spent years in Neon ACR racing. "We pulled together everyone we knew who had first-hand experience with vehicles like the SRT-4, either through grassroots racing or hitting the streets every weekend in their own performance-tuned cars."



The result was a second group of young tuners ready to continue the initial team's work. Some of them, like Stephan Zweidler and Brad Dotson, had worked indirectly on the Neon SRT concept car. Program manager Dotson had raced with Team Shelby and the Neon ACR in SCCA, including a stint as crew chief. Zweidler raced Solo II SCCA autocross throughout college and was active in the Neon Enthusiast Club. Vehicle Synthesis Engineer Jeff Reece worked on the championship-winning Dodge Viper GTS-R. Engine Engineer Tom Wierzchon (also on the Viper GTS-R team) and Electrical Systems Engineer Judy Willoughby round out the core of the PVO Dodge Neon SRT-4 team.

Dotson said it "wouldn't have been possible without the cooperation of other departments throughout the company. It's amazing to see other racing enthusiasts come out of the woodwork to lend their support for this program."

Life as an SRT-4
SRT stands for "Street and Racing Technology" and the "4" denotes the number of cylinders.

A few minor subtle changes to the production model included adding two nostrils on the front fascia to help with the upgraded cooling system, a revised boost gauge face and standard pedals.

The Dodge SRT-4 utilizes a 2.4 liter turbo motor which first appeared in the U.S. in the 2002 Chrysler PT Cruiser GT model. The 2.4 turbo motor actually began life in Mexico a few years prior to that residing in the Dodge Stratus/Chrysler Cirrus LXi sedan. Chrysler was able to get a few years of real world testing of this engine before bringing it to the states. This would allow them to address any issues that may have come up in the engines first and second production model years. The base normally aspirated 2.4 liter has been around since 1994. Contrary to belief, the base 2.4 and turbo 2.4 are different in many ways mainly inside the block.

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

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: 34.80mm (Silchrome-1)
Exhaust valve size: 28.45mm (Inconel)
Intake valve angle: 24.46 degrees
Exhaust valve angle: 23.5 degrees

The SRT-4 uses 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 6cm2 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 psi. This translates to 215 hp @ 5400 rpm and 245 lb-ft torque @ 2000rpm at the flywheel. 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" exhaust piping system, which splits into two at the rear. No mufflers. The purpose was to not only let the car breath better but to also give it 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, beefy equal-length half shafts and a Sachs high-capacity performance clutch and pressure plate. The SRT group (formally known as PVO) knew that the car was going to be driven hard and fast so they made sure that the parts that counted were up to the task.

Suspension is rounded up with 170lb F / 125lb R springs, specially valved Tokico struts, 24mm front / 19mm rear sway bars, firmer bushings, steering rack from the PT GT, upgraded knuckles and a unique K-member.



"We wanted a car that had a nice, balanced feel through the corners without an overabundance of body roll," said Fernandez, who also worked on Shelby vehicles such as the legendary Omni GLHS. "With the SRT-4, we created a car with a high dose of power that is also highly controllable."

"We've gone a little firmer on the spring rates, especially in the rear, so that we can lessen the rear end dive," said McCammon. "That allows the car to remain level and even drop down a little in the front to get you off the line faster."

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. Some of these weekend racers worked closely with the small vehicle team to make sure that their SCCA engineering experience found its way into the Dodge SRT-4. "From the onset, employees from these two groups worked together to create a car that reflects our motorsports heritage, both from grassroots Neon ACR racing and the professional success of our Viper program," said Fernandez.

Braking consists of an ABS system with 11.0-in F vented/ 10.6-in R discs and single piston calipers (57mm F/ 36mm R). The calipers come powder coated red from the factory.

17x6.0 (45mm offset) cast aluminum wheels coupled with 205/50/17 Michelin Pilot Sports help put the power to the ground. The expressive wheels were purposefully designed to look like aftermarket wheels, with tape-on weights and fuller width rim sections. The unique spoke pattern allows for better airflow to the brakes. The design shows much similarity to the TSW VX1 wheels found on the concept Neon SRT.



"Dodge SRT-4's design cues suggest more of a customized look right off the lot, but are not so overwhelming that they squelch the creativity of enthusiasts looking to personalize their car in the aftermarket," said Trevor Creed, Senior Vice President - Design. "There was a 'sweet spot' we wanted to hit by using a design theme that includes unique front and rear fascias, sill-mounted ground effects and a Mopar signature deck-mounted spoiler."

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. The Dodge crosshair grille design gives the Dodge SRT-4 a bolder face. Just behind the lower grille sits a cast aluminum intercooler.

"We deliberated about whether or not to hide the intercooler with grille textures or even paint it black," said Lance Wagner, Director - Exterior/Interior Design. "But tuners like to show off the components they've added, so we left the intercooler in its raw state to give the front end a more authentic, straight-from-the-street feel."

"The boldness of the spoiler adds to the outrageous quality of the vehicle. It's like the exclamation point on the whole theme of the car," said Wagner. The taller, basket-handle type spoiler also improves vehicle handling by generating downforce.

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 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 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 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.



"It's not just an eyewash of wannabe's," said John Ozark, Senior Product Designer Dodge SRT-4 Program. "It's a car that wants to get up and go, and the precise interior design reflects the performance under the hood." Along those lines, a special Dodge SRT-4 turbo 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.

"We considered including a sub-woofer and an amplified sound system, but that would have meant adding almost 30 pounds to the vehicle weight which, besides adding to the overall cost, would have slowed the car's performance," said Marc McCammon, Project Manager.

So as you can see, a vast amount of time and effort was used to address all the little details that make the SRT-4 the performer it is today. The car is far from just some Neon with a turbo and body kit. Although often thought of as a straight-line performer, the SRT-4's roots come from SCCA racing and the people behind it all are club racers. A package of performance, styling and quality at a low cost is what Dodge had intended for the SRT-4 and they have succeeded in this. Dodge has also shown what the SRT-4 is capable of in all avenues of motorsports as its Mopar division is campaigning the SRT-4 in Rally, SCCA and drag racing circuits.

The 2004 model received some much needed enhancements which included:

* New torque-sensing limited-slip differential developed jointly with Quaife
* Horsepower increased to 230 hp at 5300 rpm and torque increased to 250 lb.-ft. between 2200-4400 rpm
* New NGC3 engine control module and a new calibration for wider torque range
* Larger fuel injectors provide increased fuel flow
* New BF Goodrich KDW2 three-season tires are standard equipment
* Developed to match the vehicles high-performance suspension and handling characteristics, the new tires 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 replaced Bright Silver Metallic. 05 also marked the return of the ACR name plate once again with the package available only on the SRT-4. The ACR package upgrade includes:

* 16x7 BBS RX wheels with 40mm offset
* 225/45/16 BFG KDW2 tires
* 5-way adjustable Tokico Illumina dampers
* Stiffer rear tension strut bushing
* ACR embroidered Viper inspired seats with Viper harness slots
* ACR decals on the bottom doors




Also for 2005 is 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 will include:

* 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 plates




information compiled from:
www.allpar.com
www.dodgeboy.net
www.sportcompactcarweb.com
www.caranddriver.com

[BACARDI_DWB]

great post!!!! Sticky anyone???

[BoooOsted]

Nice!!

Branden

[Nick Fury]

Badass.

[Tex]

i personally liked the first interior design better

[superstrongbeast]

moderaters... this ones good THis needs to be a forever STICKY!
im actually printing it out now~~ and in my srt portfolio it goes~~ lol

[superstrongbeast]

Quote: Originally Posted by Tex

i personally liked the first interior design better

I did at first too, but now I see ricer written all over it!
a good interior for a car is....

[04BlueSRTOwner]

Very nice. Definately need to make this a sticky.

Ed

[04electricblue]

GAH THAT WAS LONG! and gooooooooood

[evo77]

Hopefully those from the SRT group that see this might grace us with a few other additions to the "birth of the concept Neon SRT" piece that I left out.

[glhs837]

Great way to gather it in, EVO!!!!!!!

[Srt4Par]

very nice post 2 thumbs up

[BACARDI_DWB]

i like the interior also but i didn't like the quilt looking seats.. other than that its good looking.. didn't know that they wanted to go the supercharged way.. glad they went turbo.. 2.4....

[Epix]

yay

[5spdfrk]

Excellent post. Grounds for teh sticky!