Tom Wilson
October 28, 2009
Photos By: KJ Jones

When the last Castrol Syntec Top Car Challenge participant pulled off Buttonwillow Raceway Park's road course we weren't quite sure how our Mustang challenger had performed. For sure it had lapped faster than the '60s-era Chevy Caprice that Lowrider magazine had just fielded--complete with air bag suspension, no less--but mentally tabulating where our entry finished was beyond our estimation.

Certainly there was no angst over the '95 Mustang Cobra and its just-concluded muscular display. Gamely fielded by 5.0 Mustang & Super Ford's reader Ron Cooper, the daily driver 'Stang laid down good real-world numbers. Keeping to the spirit of Castrol's automotive intramural, we opted for a representative, real-world Mustang. Our sister publications--this was a magazine-based get-together, after all--didn't seem similarly motivated judging from the near-race machines resting next to 18-wheeler transporters (in one case, anyway).

Like everyone else, we had to wait for the official results to be calculated and announced months later. In the meantime, we knew Ron and his Mustang acquitted themselves well.

For those who missed our feature on Ron's Cobra, it could be one of thousands of daily driven fun cars. It's original 302 expired years ago, and he replaced it with a Summit-sourced Explorer 302 short-block, Probe forged pistons, Air Flow Research 165cc aluminum heads, all aided by a Vortech V2 supercharger with a big stock pulley. A T56 six-speed gearbox replaced the original T5. Underneath, the main chassis improvements are a Maximum Motorsports Road & Track box kit, Koni single-adjustable yellow shocks, and Hawk HPS brake pads in the stock Cobra PBR-based calipers. Sticky Nitto NT01 tires, 245/45ZR-17, are on Cobra R wheels.

Besides a full complement of add-on street gear--a stereo, DVD player, 10-inch subwoofer, extra sound-deadening, seat-back-mounted TV monitors--the Cobra maintains every ounce of its original equipment, such as air conditioning, and it's seen 14 years and many miles of street use. Heck, the "new" engine had 70,000 miles on it. To put it mildly, our entrant and his 14-year-old Mustang are the personification of hands-on Mustang enthusiasm.

Testing the Castrol Top Car participants was a two-day affair, opening with a dyno test at K&N Air Filters to read the best of three power pulls, followed immediately by an emissions test. Once everyone had had a chance on the dyno rollers, the entourage rumbled through street and highway traffic on the three-hour grind up to Buttonwillow Raceway Park in California's hot central valley. Day two was dedicated to lapping Buttonwillow in search of the perfect lap.

Points were awarded mainly, but not completely, as a percentage of the best competitor's performance, which made it difficult for everyone except the officials to keep tabs on how the competitors were doing. That's mainly a good thing, as entrants tend to try too hard if they can see they're only a point behind Second place or so. With this system, there's still plenty of mental noodling, but without accurate conclusions, everyone just tried their best.

In preparation for the Challenge, Ron had his car tuned by an old friend of this magazine, Steve Ridout at Powertrain Dynamics. Steve wrote two tunes for Ron to toggle between; one for 91-octane pump gas and another for 100-plus-octane race fuel.

With the engine freshly adjusted, the only thing Ron needed to monitor on the K&N dyno during his three official runs was the ignition timing. After watching one competitor's engine show signs of imminent death during dyno competitions, we were happy to have Ron open with a conservative 10 degrees of static timing, followed by the second pass at 12 degrees, and the final at 14 degrees. That was sure to post a decent number right away--good insurance in case something went wrong at the more aggressive ignition settings.

It turns out the first run netted 440 rwhp, followed by another 10 hp on the second run. That was OK, but the engine was heating up and Ron knew rushing into the third pass wouldn't gain the power his race tune could post. So instead of icing just the intake, Ron iced the supercharger, intake tube, and IAT sensor as well to keep the computer from pulling timing. That did the 20hp trick, and the Cobra whacked out 471 rwhp.

Of course there were the usual overachievers. Some of the turbo'd import cars reached into the 700-plus-rwhp range, and just as predictably, one of them rattled a piston, putting it out of the competition just as it started.

Right after the dyno rollers braked to a stop, a probe went up the ol' tailpipe, and the Cobra was run through an idle and 2,500-rpm load test. Ron was ready for this test, too, as he had recently installed a fresh set of high-flow cats. As we once heard a New Jersey street racer say, "A new set of cats could clean up Three Mile Island." In this case, the 302 wasn't dirty to begin with, so Ron came out of the sniff test like a basket of fresh laundry.

Horse Sense: A regular haunt, Buttonwillow Raceway Park is 240 miles from our West Coast home office. The Castrol's Top Car Challenge marked the third time we'd been there in six weeks. We should be paid by the mile!