1987 Buick Grand National - By Grand Design

Alan Koprowski’s '87 Grand National was acquired with a worked motor, ready to fly. Now it can handle like an Indy Car and stop on a dime.

Andrew Nussbaum Apr 14, 2014 0 Comment(s)
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The culmination of Alan's grand vision would be the suspension and running gear. By way of his own labor he installed QA1 double-adjustable shocks, paired with QA1's 2.5-inch drop, 400-lb. rate springs at all four corners creating the perfect stance. Hotchkis front and rear sway bars aid the UMI front and rear upper and lower control arms help stiffen the chassis.

Hauling the GN to a stop from turbo-induced speeds are massive Wilwood 6-piston front, and 4-piston rear calipers, clamping down on 12-inch rotors. Once again, Crazy Don was summoned to modify and install the 12-bolt rear stoppers to the GN's 10-bolt.

The brawny Buick now rolls on gorgeous billet aluminum Bon Speed GTB wheels; 18x9-inch front, and 18x10-inch out back, wrapped in Mickey Thompson Street Comp rubber.

As for the ‘National's Vader-like black cloak, only a high-speed polish was needed to bring the factory paint up to an impressive deep glossy shine.

Leaving the clean cockpit mostly stock, Alan ditched the stock gauges and emulated the great GNX cars with a Performance Instruments analog cluster.

Being a rock ‘n roll guy, Alan sought to enhance the already adrenaline-pumping driving experience by installing a JBL 1,000-watt base amplifier and 600-watt speaker amp, to a Sony radio/CD head unit, to better hear his tunes over the shriek of the 60mm hair dryer.

Since completion in early 2013, Alan has been blown away by the super-car performance of his nearly 30-year-old Buick. "It rides like a go-cart," Alan says, when describing it's handling characteristics. Merging onto Long Island parkways is always fun, as the ‘National pulls like a Lear jet to gain the left lane, while all takers from pricey exotics, to hoped-up modern musclecars, learn a lesson they'll never forget.

Even with all the work and radically lowered stance, there has been no sacrifice in drivability. Alan enjoys driving his Grand National everywhere through the spring and summer months, often attending car gatherings, bringing home six best in class honors at local shows.

Unbelievably, Alan has some very definite future plans for his bad-to-the-bone Buick, which include a larger turbo, a more aggressive tune, 33-spline axles, and a hardened crankshaft—If not an entirely new short-block.

Although he never plans to test his black beauty at the track, there can be little argument that Alan's goal of building a world-class, ultra-high performance coupe has certainly come to fruition. With well over 500 hp on tap from the mild tune, and the potential for at least 100 more, prowling the highways and byways of Long Island like he owns them is a forgone conclusion.

Data File

Car: 1987 Buick Grand National
Owner: Alan Koprowski
Block: 3.8L "109," bored to 4.1L
Compression ratio: 8.1
Heads: Duttweiler Performance Aluminum
Cam: Comp Cams custom grind Buick BV69 Hydraulic flat tappet 221/221 duration at .050,494/494 inch lift, 112 LSA
Pushrods: Stock
Rocker arms: Stock;1.6 ratio
Pistons: Ross; forged
Rings: Stock
Crankshaft: Stock
Rods: Eagle; forged
Throttle body: Stock
Fuel injectors: 60-lb.
Fuel pump: Red in tank pump with hot wire kit
Ignition: MSD DIS-4+ Digital Timing Box
Engine management: Stock VCM with custom tune via Gen-2 Transdapter by "Indian Mike"
Power adder: Precision 60mm turbocharger
Boost: 25lbs
Intercooler: RJC Megacooler
Wastegate: Stock
Exhaust system: 1 3/4-inch primary mid-length headers, 3-inch pipes, MAC FloPath mufflers
Transmission: 2004R; built by Charlie Sagona
Torque converter: Hughes 3500-stall, 9.11 lock-up torque converter
Driveshaft: Stock
Front suspension: QA1 double adjustable shocks, QA1 400-lb. rate 2 1/2inch lowering springs, Hotchkis sway bar, and UMI upper/lower control arms
Rear suspension: QA1 double-adjustable shocks, 400-lb. rate 2 1/2inch lowering springs, Hotchkis sway bar, and UMI upper/lower control arms
Rear end: GM 10-bolt; TRUTRAC Posi, 3.73 gear, TA diff cover
Brakes: Wlwood 6-piston front, 4-piston rear calipers, 12-inch rotors front/rear
Wheels: Bon Speed GTB (billet); 18x9 front, 18x10 rear
Front tires: Mickey Thompson, street Comp 235/40/18
Rear tires: Mickey Thompson Street Comp 275/40/18
Fuel: pump gas (93 octane)
Race weight: (est.) 3800-lb.
Best ET/mph: N.A.
Best 60-ft. time: N.A.
Current mileage: 66k
Miles driven weekly: few

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