(all photos on this page) These photos show the prototype "tray" and its discharge air tube, whichleads from the scoop to under the engine and ultimately the air filter,along with the tubing that transports the "scooped" air to the airfilter. They also show what's under that big hoodscoop.
Vortech was surprised by the strength of our press-car Cobra. The company had tested two private-owner Cobras previously, both of those putting out high-200hp figures on the company's Mustang dyno. Our car was maybe 30 hp stronger than these other Cobras. So a STAR tester was hooked to the Cobra to read out its boost and ignition timing. The Cobra boost started at 7.2 pounds at just 2,200 rpm, an impressively low rpm for such manifold pressure. By 2,600 rpm, it was making 8 pounds. It peaked at 9.5 pounds at 4,300 rpm, then fell to 8.6 pounds at 6,380 rpm, which all sounds correct. The ignition timing was a stout 23 degrees around the power peak, another typical Cobra value. So, it would seem we had a good, fresh, strong-running Cobra.
To the Scales
Our next stop was the truck scales. Modern cars are heavy, as the following chart shows.
Front: Cobra - 2,080; Mach 1 - 1,900
Rear: Cobra - 1,580; Mach 1 - 1,560
Total: Cobra - 3,660; Mach 1 - 3,460
All figures are in pounds.
Both cars had a half tank of fuel and were weighed without drivers. More importantly, the Mach 1 benefited from its Griggs suspension, which Griggs Racing said should account for a 65-pound reduction on the front axle. Still, at 200 pounds, the Cobra's weight penalty was significant in this test. Even without an aftermarket suspension on the Mach, the Cobra would definitely outweigh the Mach.
Side-by-Side
It's interesting how theory often goes under the bus when the pedal hits the metal. Much of this seems to be less than expert prognostication by those involved--namely us--and some of it is how much perception and emotion count compared to columns of numbers on a dyno sheet.
Going into the side-by-side trials, everyone involved just knew the Cobra would lunge to an immediate--if modest--lead, then be passed by the Mach as the contest continued. We were wrong.
In reality, with any rolling start, the Mach walks away from the Cobra, end of story. The only exception was from a slow, nearly lugging Third-gear start. Then the Cobra pulled a fender on the Mach, only to have the Mach trot on by within a second or so. Even when we cheated and started the Cobra in First and the Mach in Second, it was Mach all the way. The Mach's advantage held as speed rose. Believe us, the Cobra was never going to run down this Mach no matter how far the pair ran out the back door. Only if the Mach 1 pilot was asleep and the Cobra driver lying in wait would the outcome be in any question, and then only for a short time. So, the bottom line was both cars would begin accelerating, and for the first half second there was no relative motion. Then the Mach would begin steaming ahead, constantly pulling a lead on the Cobra.
We did not attempt any standing-start runs, but the results are predictable. The Mach, with its live rear axle, could use the more aggressive launch, and our particular Mach, with the torque arm rear suspension, would simply plant the rear tires and leave. The Cobra's IRS is sensitive to pavement characteristics, so it may have allowed a modest launch or wheelspin, depending on traction. So the Mach would win again.
Seat of the Levi's
Once again we're reminded how Mustang Cobras can feel heavy and slightly unwieldy around town or on tight secon-dary roads. It's a perceptual thing, coming from cues as subtle as the thick steering wheel, the somewhat high steering effort, the clunky shifter action at parking-lot speeds, the shifter being too far forward, the heavy clutch pedal, and even the overstuffed bolsters in the seats that cramp all but the smallest drivers.