5.0 Mustang & Super Fords
1997 Ford Mustang - Green Machine
Dave Martis Had The Envy Meter Deep In The Green When He Rolled Out His New American Iron Extreme Racer
Covering all this stuff you can't really see is some form-following-function beauty you can. Again, Dave reached for the Griggs catalog to select the hood, rear spoiler, and front bumper cap. The latter is a wonderfully subtle bit of urethane featuring slightly larger foglight and grille openings for better brake and engine cooling-the cooling ducts are built in. The hood is a Heat Extractor GR40 fiberglass unit. The spoiler is a carbon-fiber part with NASCAR style stiffeners. Mimicking the hood louvers are similar units in the stock steel front fenders.
But it's the mod-motor power under the hood louvers that really sets apart Dave's creation. Beginning with an aluminum Cobra engine from a donor car, Dave disassembled the core. The bottom end was machined by Dougan's Rebuilding & Machine Shop in Riverside, California, and the heads received a high-rpm tuning package by Griggs.
Clearly rpm is the name of the game with a small-displacement, multivalve engine, hence the short-runner Griggs-modified Cobra intake manifold. Filtration is by K&N and the throttle body is FRPP's oval-bore unit. There is no mass air meter, as the engine is sparked and managed by an ACCEL Gen VII DFI system working with NGK plugs and MSD wires. Fuel is supplied from the 25-gallon Fuel Safe cell by a Weldon 2025 pump and custom-bent -8 stainless steel supply and -6 return lines.
Billet fuel rails from Steeda, a Weldon fuel-pressure regulator, and RCI 42-lb/hr Lucas fuel injectors round out the system. The engine is also dry-sumped.
Dave built his own custom headers using computer-designed merge collectors and tubing from Burns Stainless in Costa Mesa, California. The results are stainless step headers starting at 1 7/8 inches at the port exit, moving up to 2 inches, and finally 3 inches at the merge collectors. This is followed by a custom 3 1/2-inch diameter (nominal) oval-shaped exhaust system with X-pipe. The oval stainless tubing is from SpinTech. It allows increased ground clearance required by the track-hugging ride height.
Also a concession to a low ride height is the Quartermaster 7.25-inch-diameter triple-disc clutch and matching Quartermaster bellhousing with rear starter mount. It supports a Jerico five-speed road-race transmission, and if you haven't had the pleasure of sampling one of these strong yet slick-shifting boxes, you're missing a real treat. It's like drawing two magnets together. Dave uses a custom Irv Hoerr Racing Products shifter and is pleased with his transmission choice. He's really excited about the easy, no-clutch, no-lift shifts.
The Jerico and its individually adjustable gear ratios are also important elements of Dave's low-torque, high-rpm Four-Valve strategy. His plan is to use all five speeds, meaning going into First gear on the slowest corners and having fifth just tall enough for the longest straight. This requires plenty of shifting, but it also means the somewhat peaky Four-Valve will buzz along in its powerband at all times. "Like a 125 shifter kart," Dave says.
The slick shifting is not without a price. The Jerico is longer than a Mustang gearbox, with the shifter naturally sprouting through the console where the stock hand-brake lever resides and the box hitting the floor's tunnel. This required cutting the top of the transmission tunnel and fitting a new, fabricated tunnel cover/housing. This modification, and the almost $6,000 cost of a new Jerico (Dave bought his used for considerably less) both just get by the AI Extreme rules.
It would be fun to say Dave laid waste to the American Iron field at his Fontana debut, but not so. Having only 4.10 gears that weekend, he was just going to shake down the car as the gearing was far too short for the long Fontana straight. That lasted about one lap, as Dave savored winging his super-crisp Four-Valve V-8 to 8,000 rpm for the first time. One broken stock valvespring retainer later, the intelligence of having stuck with the original plan was apparent. Dave is taking the enforced rebuilding time to prep a set of the newly released FR500 heads and magnesium-intake manifold. Griggs will once again do the porting, and this time Dave says he'll likely use titanium retainers.
In the meantime, Dave is one of a small club of Four-Valve road racers. Watch out when all this airflow is put to full use.