On the Track
With the exception of the...
With the exception of the splitter, hood, and wing from G-Stream, the Boss 302S bodywork is stock. Successful racers such as Paul soon learn to cover as much of that bodywork with sponsor and contingency stickers as possible.
Our track plans were extremely simple. We'd meet Paul Brown at Willow Springs Raceway and drive both cars on the big track and compare notes. Because the street car is designed to function as a track car, no special preparation was made other than ensuring the oil was topped off and the gas tank full.
To reduce one major variable Paul suggested we use a set of Pirelli race tires from his car on the street car, which we did. This made our comparison much closer and is typical open-track practice where owners often have a dedicated set of track wheels and tires. You'll want to spot your Boss about four seconds per lap from our numbers when running on its stock tires while open-tracking.
Lap and segment times were gathered via Race Keeper, a video data logger Paul uses on his race car. Race Keeper kindly provided a second system, which was temporarily mounted on the street car, and with nothing more exotic than a couple pieces of tape, the Race Keeper box attached to the passenger carpet, plugged in, and powered up through the cigarette lighter. With that set, we were ready to test.
Willow Springs is an open, medium-to-fast track. It places a premium on high-speed stability, power and momentum, provides a brief technical section and is easy on brakes. Thus, it won't make the typical sloppy street chassis stumble completely over itself, but those high-speed corners punish lap times if the chassis is inconsistent. It's definitely not the place for white-knuckle handling lotteries like a stock Fox body.
While street Boss 302s have...
While street Boss 302s have a small splitter, we bet it’s more for looks than function unlike the G-stream splitter on the 302S race cars. Otherwise the front fascia on the race car is identical to the street car, down to taking brake-cooling air through the foglight apertures. The hood is another G-Stream part and is heavily louvered to vent hot, high-pressure underhood air. After sampling the 302’s improved stability in high-speed corners we’re pretty sure it works, too.
Paul and your author each drove both cars, and our evaluations, if not our lap times, were similar. Our notes on the street car are full of superlatives, but inevitably as the speeds went up the street Boss was pushed to the limit of its composure and the need to add small corrections inevitably crept in. Naturally it also had a little understeer at the limit—all street cars do—but a whiff of throttle would pick up the front end and get things neutral again. But above all, the Boss was well composed and devoid of surprises.
Is that ever faint praise for what was an amazing track experience with a street car! We'll be honest, the Boss 302 is not the first modern Mustang we've driven straight to the road-racing circuit and drove it like we were qualifying for Daytona, then drove home. But it's the first one without a king's ransom in aftermarket augmentation, and it easily did the job better. Sure, there's degradation near the limit, but for a civilized, showroom-stock street car with a five-year/60,000-mile powertrain warranty, emission certification, and a 26-mpg EPA highway rating the Boss takes to the track like a second home. We were amazed by its gifts.
A few things started to show while cornering at 130 mph. Recaros or not, in Willow's long sweepers we found ourselves working to hold ourselves up in the seat, a universal failing of street seats at the track. We quickly determined our left butt cheek and the outer section of the seat bolster would lock together sufficiently to keep us from sliding all the way into the door panel, even if it wasn't the most comfortable position to maintain.
G-Stream is likely best known...
G-Stream is likely best known for its rear wings, and they are found on all sorts of production-based race cars. Paul says it’s low-drag for the downforce it makes, and our data tends to agree. With the street and race cars relatively close on power, the race car was 11-mph faster than the street car at the end of the longest straight, so we don’t think the wing can be cause that much drag.
We also noted a near constant nibbling or extremely small notches in the grip when cornering hard. It was a subtle and unique sensation—for awhile we were wondering if we were really feeling something or if our mind was playing tricks on us—until we realized we had not gotten the traction control switched all the way off. We're glad we experienced the sensation because it proved the Boss has a sophisticated, soft-touch traction control that doesn't come barging in on the party.
It's also likely the stickier race tires were mildly upsetting the traction control's carefully calibrated algorithms, but in any case the Boss's traction control is a subtle thing. Then it was our turn in Paul's race car.