The sudden influx of turbocharged cars in America may lead some to believe the Subarus and Mitsubishis of the world invented the market of affordable forced induction.
Nothing is further from the truth, according to Mark Grant of Granite Falls, N.C. His 1992 Dodge Daytona IROC R/T is one example of an affordable turbocharged platform that was available before even a handful of Americans ever heard of an EVO or a WRX.
Grant's involvement with these vehicles began in the typical way. Ten years ago, he was looking for a used car to have a little fun with, something with decent room, a hatchback preferably, and good out-of-the-box performance. Eventually, the search led him to a Shelby Charger, which was the predecessor of the Daytona. It incorporated a strikingly similar chassis and an earlier version of its 2.2-liter turbo engine, but with a single overhead cam and two valves per cylinder. Though the Charger's performance wasn't steller, packing only 150 hp, Grant's enthusiasm for the platform quickly grew, and it wasn't long before he discovered the ultimate Chrysler 2.2-based sport coupe, the Daytona IROC R/T.
If you've never seen or heard of this particular vehicle, there's a good reason for it. The Daytona IROC R/T was produced only in 1992 and 1993. Initially, it was to be released in a limited run of only 800 cars. This number was never achieved, however, and in the two years less than 500 were built. The car came with such standard niceties as a driver's-side airbag and leather-wrapped steering wheel, air conditioning, four-wheel disc brakes, a sport-tuned suspension and Z-rated tires on 16-inch cast-aluminum rims.
For Mark Grant, however, its biggest selling point was its engine. The Daytona R/T was built as an enthusiast's car, and as such it was imbued with a much more muscular version of the 2.2-liter Shelby Charger engine. The Daytona R/T's 2.2 was factory-assembled with forged internals and a Lotus-designed, DOHC, 16-valve cylinder head. A Garrett T3 turbocharger providing 11 psi of boost and radiator-mounted intercooler core pushed engine output to 224 hp at 6000 rpm, and 217 lb-ft of torque at 2800 rpm-impressive even by today's standards.
Because he likes to autocross more than he likes to haul ass in a straight line, Grant's initial mods to the vehicle were suspension-based. And because there isn't much available for these cars in the way of aftermarket performance, he had to make a lot of the parts himself. Today, he and his father, Terry, fabricate and sell their own parts for the Daytona R/T and its Daimler-Chrysler relatives, like the Dodge Shadow and Chrysler LeBaron, as well as certain DSM vehicles (think Eagle Talon) under the GrantRacing company name.
Mods beneath the chassis include custom coil-overs comprised of specially made springs and adjustable Koni struts and shocks. The spring dimensions and rates were carefully formulated using spring testers at all corners and quite a bit of trial and error. Grant also fabricated front and rear strut and shock tower braces, as well as a stainless-steel adjustable Panhard rod and adjustable rear spring perches. The front strut tower brace incorporates adjustable camber plates to dial wheel angle for track events. Other additions include Energy Suspension urethane bushings on the front anti-roll bar and a 5/8-inch Addco rear anti-roll bar. The four-wheel disc brakes were left untouched except for braided stainless-steel Goodridge lines and KVR carbon/Kevlar pads. Rolling stock consists of Racing Hart C5 three-piece wheels, sized 17 x 8 inches, and Toyo Proxes T1S tires sized 255/40R-17.
When the suspension was tuned to his liking, Grant turned his attention to the engine, and to date, he's put quite a bit into raising its reliability and performance. The Lotus cylinder head-both a blessing in its efficient design and a curse in its inherent Lotus reliability-had to be removed and heat-treated, then reapplied and attached using ARP head studs. Beneath the engine, Grant removed the balance shaft assembly and installed a custom windage tray inside the stock oil pan to prevent whipping his lubrication into a frothy mess during his spirited autocross sessions.
Airflow has been revised using a custom aluminum intake, fabricated by GrantRacing, a new 58mm throttle body, and on the engine's hot side, a 2.5-inch stainless-steel exhaust with a SuperTrapp muffler. The forced induction system still uses the stock Garrett T3, but it's been modified to boost performance. Grant ported the turbine and compressor housings and the exhaust manifold and used HPC heat-resistant coatings on the manifold and compressor housing.
Grant also upgraded the intercooler system, first by removing the factory core from the radiator-which itself was replaced with a custom-made aluminum Fluidyne unit-and moving it out front. Then he replaced it completely with a larger, more efficient unit taken from a Porsche 944.
An adequate supply of fuel is provided by an adjustable billet-aluminum fuel pressure regulator, Aeroquip braided stainless-steel lines and Mopar Performance 42-lb/hr fuel injectors. Boost and fuel curves are regulated by a reprogrammed ECU from Neil Emiro at ND Performance.
An array of system meters, including Auto Meter air/fuel and fuel pressure, GReddy EGT arranged on the top center of the dashboard, as well as a pillar-mounted A'PEXi boost gauge, allows him to keep an eye on the underhood goings-on. The OC Monitor 4000 diagnostics computer, mounted to the right of the dash gauge cluster, is what Grant uses to fine-tune the engine. Other additions to the car's cockpit include a hatch-mounted Optima battery and custom short-shifter assembly with a Hurst "cue ball" knob. In the future, Grant plans to add competition seats and a roll bar.
At 14 psi of boost, Grant tells us the Daytona currently lays down 271 hp and 270 lb-ft of torque at the wheels. Even though straight-line performance isn't what he's after exclusively, the numbers are pretty impressive for a front-wheel-drive car that just turned 12 years old-hell, they're impressive for a new car, too. As for the man himself, he continues to drive the car regularly in autocross Solo I and II events and devise further upgrades for his platform of choice.
|1992 DODGE DAYTONA IROC R/T |
|Engine Code ||Turbo 3 |
|Type ||Four cylinder, cast-iron block, |
| ||aluminum head, turbocharged |
| ||and intercooled |
|External Modifications ||GrantRacing aluminum intake, |
|58mm throttle body, GrantRacing |
|baffled oil pan, Fluidyne radiator, |
|ported and HPC-treated exhaust |
|manifold, ported turbine and |
|compressor housings, Porsche |
|944 front-mount intercooler |
|with GrantRacing aluminum |
|plumbing, ARP head studs, HPC- |
|coated valves, Quickor front |
|motor mount, custom 2.5-inch |
|exhaust with Supertrapp muffler |
|Engine Management Mods: ||ND Performance ECU, |
|GrantRacing adjustable fuel |
|regulator, Mopar Performance |
|injectors, Aeroquip braided |
|stainless-steel lines |
|Layout ||Transverse front engine, |
| ||front-wheel drive |
|Drivetrain Modifications ||Transaxle mount, urethane |
| ||shifter bushings, short shifter |
| ||all by GrantRacing |
|Front ||GrantRacing coil-overs, Koni |
|adjustable struts, GrantRacing |
|front strut tower brace and |
|camber plate assemlies |
|Rear ||GrantRacing coil-overs, Koni |
|adjustable struts, GrantRacing |
|adjustable rear spring perches, |
|GrantRacing adjustable Pan |
|hard bar, Addco anti-roll bar, |
|GrantRacing rear shock tower brace |
|Front ||Goodridge braided stainless-steel |
| ||lines, KVR carbon/Kevlar pads |
|Rear ||Goodridge braided stainless-steel |
| ||lines, KVR carbon/Kevlar pads |
|Wheels ||17x8-inch Racing Hart C5 |
|Tires ||255/40R-17 Toyo Proxes T1S |
InteriorAuto Meter air/fuel ratio and fuel pressure gauges, GReddyEGT gauge, A'PEXi boost gauge, OTC Monitor 4000 diag-nostics computer, hatch-mounted Optima battery