We see a lot of different cars here at the editorial offices of Primedia's International Performance Group. Working off and on at five different magazines, I think I've probably seen them all. Truth be told, I've seen some pretty stupid ones, but I've also seen a lot of crazy fast ones. In terms of all-out performance, the most impressive are without a doubt track-bred competition racers, cars that make 400, 500, 600 or more hp, with totally stripped interiors, rock-hard race suspensions and super-soft track-only tires. The kind of cars which make emissions control technicians and EPA tree-huggers wake-up screaming in the night.
For real-world performance and practicality--after all, isn't that what production vehicles are all about? The most impressive cars are the ones that run sick numbers at the track, then drive off the asphalt, onto the street and all the way home without so much as having their wheels changed. Such is North Lawrence, Ohio resident, John Shepherd's, claim to fame. His car, the 1991 Eagle Talon pictured, is used as a sometime daily driver but remains capable of turning high 9s down the quarter mile, without any track-day modifications and on the same street radials that get Shepherd to and from work. It is, in fact, the first street-class car to run in the 9s since the IDRC changed its rules to allow only radial tires in competition.
At the time Shepherd purchased the car, from none other than famed DSM tuner David Buschur, it was already heavily modified and running in the 11s. Since then, the only things that remain the same are the body, paint, wheels, intake manifold and fuel cell, and Shepherd has managed to shave about two seconds off the car's low e.t. Initially, he was able to work the Talon into the 10s by tinkering with the original 20G turbo setup, but as Shepherd himself says, "It was not enough."
In the following months, Shepherd rebuilt the 4G63 powerplant and overhauled the existing forced induction system to make this Talon the confirmed 9-second scorcher it is today. Block machining duties were handed to Story Motors in Massillon, Ohio, but actual assembly was carried out by Shepherd himself. Forged Crower rods link a factory crankshaft to 8.5:1 Ross pistons. The oiling system remains untouched. BCE Racing in Rancho Cucamonga, Calif., modified the head by enlarging the ports for oversized (1mm larger) stainless-steel valves on both hot and cool sides. These valves are actuated by HKS camshafts with 272-degrees of duration on intake and exhaust sides. The valves return to their seats via doubled-up springs, and titanium retainers keep them in check. The rest of the valvetrain remains the way Mitsubishi (whoops, I mean Eagle) built it.
The forced-induction system was upgraded using an HKS manifold, which supports a new T4 turbocharger fabricated to Shepherd's specifications by Forced Performance in Kyle, Texas. After driving the turbine wheel, wasted gases are piped out the back through a high-flow 3-inch Buschur Racing exhaust system. On the cool side, the charge air is piped through a Buschur Racing intercooler setup, based around a 22x14-inch front-mount Spearco core, and directed into a Buschur Racing intake manifold. Fuel enrichment and ignition duties are masterminded by a Professional EFI Systems stand-alone engine management computer. This fully programmable unit directs an augmented fuel system featuring an SX fuel pump, SX pressure regulator and RC Engineering injectors. For extra thrust, a Nitrous Express 100-shot, single-nozzle injection system has been plumbed into the intake tract. The application of nitrous is also controlled by the Pro EFI computer, delivering 100 hp according to pre-set engine rpm and throttle angles determined by Shepherd and his trusty lap-top computer.
The drivetrain has been bolstered with an an ACPT carbon-fiber driveshaft and ACT 3,200-lb pressure plate and street disc clutch assembly, which actuates a lightened Fidanza flywheel. The transmission was reassembled by Shepherd according to his own formula for success--but retains its original factory gear ratios. The factory differentials remain in place.
In the interest of preserving the drivetrain's mechanical integrity Shepherd has developed a unique way of launching his DSM street rocket out of the hole so no undue stress is placed on any of his carefully selected and assembled components.
"I try and ease it out of the hole and sacrifice my 60-ft times to keep the car together," he says. I asked him if he ever just drops the clutch, and he replied with an emphatic "No." So far, his method seems to be working, with no reliability problems to speak of.
While the sedate, factory-looking exterior won't overtly state this car's true nature, other than the Spearco core staring ominously through the front bumper, a look inside the car's interior will give you an idea of this machine's latent performance potential.
Shepherd still calls it a street car, and drives it that way a couple times a week, but the cockpit is definitely Spartan--crank windows, no A/C. The factory carpeting is still there, but all seats have been removed. The driver's seat was replaced with a Summit Racing bucket strapped with a RCI harness. The dash has been crammed with various electronic equipment, including five Auto Meter gauges reading oil pressure, water temp, boost, fuel level and fuel pressure, a GReddy system meter reading EGT, the nitrous toggle switch, and the HKS EVC electronic boost controller.
A Momo tiller keeps the car pointed down the straight and narrow. The six-point chrome-moly cage you see in the pictures has since been upgraded to an NHRA-approved 12-point chrome-moly frame fabricated by Gary Reese Chassis.
Suspension mods have been limited to a DSS coil-over system and a Suspension Techniques anti-roll bar in the rear. Mods to the brakes have been limited to braided lines for better pressure delivery. The Talon's rolling stock, 16x8-inch Volk TE37s and Toyo RA1 tires, sized 225/50ZR-16, is what Shepherd uses on both street and strip. The car's best 1320 jaunt to date, 9.89 sec. at 148 mph, was made using the Volk alloys and Toyo rubber.
Those involved in IDRC racing, especially street class or DSM racers, will undoubtedly know Shepherd's name. He was kicking ass and taking names at IDRC events all last season, winning six out of six races. For the new season, he says he's interested in pursuing the top names in NHRA's import drag series. Considering what he's done with this car, I would think the NHRA street class competition and Ari Yallon, who ran the table himself in 2001, winning all the NHRA events, may start to feel the heat on their respective backsides right about now. Keep an eye on future IDRC and NHRA street class races for more on the first Street-Class DSM to blast into the 9s.
The 4G63 looks good and hits...
The 4G63 looks good and hits hard.
Boost pressure, normally set...
Boost pressure, normally set at 30 psi, is monitored by HKS' EVC EZ boost controller, which is mounted in the center dash next to Shepherd's nitrous activation switch.
Shepherd switched from 20G...
Shepherd switched from 20G turbo to a custom T4 unit that mates to an HKS exhaust manifold for his assault on single-digit e.t.s.
Shepherd installed a larger...
Shepherd installed a larger Buschur Racing intercooler, which relies on a big 22x14-in Spearco core to ensure efficient operation of the Talon's forced induction system.
For extra "oomph," a 100-hp...
For extra "oomph," a 100-hp shot of Nitrous Express laughing gas can be activated by a toggle switch mounted where the factory stereo would be in your average road-going Talon.
Shepherd's low e.t. of 9.89...
Shepherd's low e.t. of 9.89 seconds was made using Volk TE37s and Toyo RA1 street tires.
Fuel, ignition and nitrous...
Fuel, ignition and nitrous management duties are handled by a Pro EFI stand-alone computer, which basically replaces the car's ECU with a lap-top programmable set-up.
In true sleeper fashion, the...
In true sleeper fashion, the car's exterior does not overtly state this Talon's 9-second nature, but a peek inside the Spartan cockpit might give you some clues.