Mid-8s at 161 mph. Wow. It's amazing how much punishment a well-built engine can take. Over the last year we've taken our Coast High Performance-built 351-based 408ci Ford Windsor stroker and flogged it on the engine dyno twice (once when we built it and again when we swapped in a solid-roller cam), ran it in a street/strip '86 Mustang coupe as part of a Ford vs. Chevy shootout against a '71 Nova with a 406 Chevy, and ran it on a chassis dyno with nitrous. Our latest excursion puts the versatile 408 between the framerails of a serious car capable of harnessing the full potential of its power. At our previous chassis-dyno session, we managed to lay down over 500 rear-wheel horsepower on the motor alone. Then we upped the ante with a 200hp shot of giggle gas from an HVH/Nitrous Express Gemini Twin system and produced over 700 hp at the rear tires (see "700 hp at the Wheels!" Dec. '02).
With all that power and a solid foundation to run it with, there was an unbelievable amount of bench racing going on around here before the first actual pass was made. According to our calculations, a motor making just under 900 hp at the flywheel in a car with a tuned chassis weighing 2,790 pounds with driver is capable of mid-8s at close to 160 mph in ideal conditions. Unfortunately, we rarely have ideal conditions when testing, and setting up a chassis just right requires a lot of time and tuning. The air is usually terrible at our track, which is located at a 2,700-foot elevation in the desert. The track is usually covered with dust, and if there's any crosswind you can forget about going straight. Our fantasy of dipping into the 8s on a crate motor seemed to be just that-a fantasy. But we figured if we could muster a run faster than our previous best of 10.17 at 137 mph made in the Mustang with a 150-shot of nitrous, we'd be making progress.
Friday TestingAfter heading to Sleeper Suspension Development to get some expert help in setting up the '85 Mustang's four-link rear suspension, another late-night thrash session ensued. Robert Varoujanian (RV) of Fast Track Performance, owner of our test mule, finished off the last-minute details, including bolting on the front clip (oddly missing in our last installment!), fabricating a sheetmetal aerodynamic wing, and wiring in all the switches. He finished off the night (which turned out to be 5:30 in the morning) by completing the parachute mount we hoped we'd need at some point. With no time to sleep, we filled the nitrous bottles and headed to the track in hopes of breaking our previous record.
As luck would have it, the wind was up, with 20- to 30-mph crosswinds. Nevertheless, we unloaded the trailer, did a once-over, launched at 4,000 rpm on the transbrake, and ran a throttle-lifting 11.31 at 126 mph with the Mustang's rearend violently bouncing and swaying. That behavior continued until the fifth pass of the day when RV was able to keep his foot on the throttle (see "Settings" sidebar) for a 10.66 at 130.51 mph.
With our testing session quickly coming to an end and the wind finally starting to die down, we increased the launch rpm from 2,000 to 2,800 and achieved a more respectable elapsed time of 10.47 at 130.89 mph. We knew there was still room for improvement if we could stop the rear of the chassis from bouncing all the way down the dragstrip. We softened the rear shock setting for our final pass, and, because our sixty-foot times were improving, increased the launch rpm to 3,500. RV blasted out of the gate with a 1.45-second sixty-foot and broke into the 9s with a 9.89 at 139.51 mph. Not bad for a pump-gas motor. Although we'd have to wait for another day to test the NX/HVH nitrous system, it looked as if the 8-second zone might not be such a fantasy after all.