Stephanie Davies Associate Online Editor
December 8, 2014
Photos By: Dominick Damato

Bobby Grasch knows his ’86 Mustang like the back of his hand.

After dropping multiple unique engines into this Vapor Silver ’86, this twin-turbo, street-legal beast is the final result of years of hard work and busted knuckles.

“Over the almost 11 years that I have owned this car, it has gone through many transformations,” said the New Berlin, Wisconsin, resident. “Each year, it got progressively faster, but I always wanted to maintain a level of streetability with it.”

After a menagerie of engine builds, including a 393-cube Windsor with a five-speed, and a 427 Windsor built and rebuilt with different power adders and internals, Bobby decided to switch it up—again.

“Believe me, those setups were a lot of fun, but as the car got faster and faster, it drifted further and further away from what I considered a streetcar. It ran on race gas, had an air-to-water intercooler, and had no overdrive. I did drive these setups on the street, but I ran the car on pump gas to putt it around so I couldn’t jump on it. Lame,” he chuckled.

In 2012, with a fastest run of 8.38 in the quarter-mile under his belt, a light bulb went off in Bobby’s head. “I no longer wanted a race car that could be driven on the street. I wanted a true streetcar that ran and raced on pump gas that I could drive a lot! So I traded my race-oriented motor for a more street-oriented one from my engine builder, and sold off the old single-turbo kit in favor of building my own twin-turbo setup.”

The resulting build is comprised of a Dart 351W 9.5-inch deck block bored and stroked to 375 ci and with a compression ratio of 9:1. An Eagle 4340 forged crankshaft works with custom Race Tech pistons via Manley 4340 forged connecting rods. The engine was built by Jamey at Flyin’ J Racing Engines in Bellechester, Minnesota.

“The engine was race-prepped and assembled. I’m not sure exactly what is done, but it was line-honed, the cylinders were bored, the cylinder head deck was checked for straightness, and the rotating assembly was balanced. The intake was also port-matched using Fel-Pro 1262R gaskets.”A Precision Prepped Melling oil pump pumps oil and a Canton oil pan seals the bottom end.

Brian Tooley Racing of Bardstown, Kentucky, is responsible for the custom grind on a Comp hydraulic-roller camshaft, as well as the work done to the AFR 205cc aluminum cylinder heads, which have undergone a blended valve job and the installation of a maximum pressure dual-spring kit. Stainless steel AFR race intake and exhaust valves measure 2.08 and 1.60 inches respectively, and Comp Cams Pro Magnum roller rockers (1.6:1) have also been installed.

A C&S Specialties 900-cfm Aerosol Billet carburetor sits atop the powerplant with a Superior Airflow carb bonnet and an Edelbrock Super Victor intake manifold. An Aeromotive Billet belt-drive fuel pump paired with a 13202 regulator (6-psi base and 25-psi under boost) supplies the gas. MSD components handle a chunk of the ignition duties, including an MSD HVC II coil, a Pro Billet distributor, Super Conductor wires, and an MSD-7531 ignition box.

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Twin BorgWarner S300SX3 60mm turbochargers from Reed at Work Turbochargers produce 14 psi max and are paired with a custom air-to-air cooler from Noodles at Behind Bars Race cars in Lake In the Hills, Illinois. A sweet rumble is created when exhaust is carried through flipped JBA shorty headers to Dynatech Bullets mufflers via 3-inch downpipes.

In regards to the transmission, Bobby said, “I wanted something with overdrive that I could race reliably without investing a ton of money. The 4L80E (built by Dave at Proformance Racing Transmissions in Elburn, Illinois) fit that bill perfectly.”

In order for the Fox to ride as comfortably as it does, he installed Strange single-adjustable shocks. Hypercoil springs have been installed up front, along with a Flaming River manual rack, Team Z caster/camber plates, and RaceCraft 2-inch drop spindles. In the rear, Wolfe double-adjustable upper and lower control arms reside with AFCO double-adjustable rear shocks and Hypercoil rear springs. A Wolfe antiroll bar and a custom subframe connectors have also been installed. The housing and axles have been narrowed 3/4 inch on either side to fit with the mini-tubbed rear.

Finally, Bobby knew that his once-race car needed a cosmetic makeover to really complete the transformation into a street car. “It had flat black paint, so it looked like a drag car. I wanted something kind of subtle that made the black trim I love so much on the ’86s pop, so I picked the Vapor Silver.”

An HO Fiber Trends 4-inch fiberglass cowl hood was added, along with Cobra Replica wheels, which were narrowed in the front to keep just a subtle hint of a “drag” look.

Inside, a custom 10-point cage by Tom at OTE Design and Fabrication keeps Bobby safe both on the street and on the track. Custom Speed Hut electronic gauges (including a GPS 180-mph speedometer) have been mounted in the factory dash bezel, which remains mostly stock with the exception of later-model Foxbody seats.

The result of the build is a cool 9.50-second quarter-mile Mustang that traps at a speed of 148.22 mph running on 17-inch drag radials with 93-octane fuel. Bobby says the car probably makes approximately 750 hp to the rear wheels, though it has never been proven on a dyno.

“Do I miss how fast the car used to be? At times yes, but I have a lot more fun with the car now because it is so much more useable and drivable. I wouldn’t go back if I had the chance!”