Well for those in need of a quick history lesson, the Grand National began production in '84, having a draw-through carburetor setup passing through the turbo into the engine (not the best setup for turbo). By 1987, the Buick Grand National and GNX (limited production, more HP & suspension) was the fastest american production car on the road, base models were posting mid 14's in the quarter, and the GNX's would post low 14's and even tickle the high 13's, stock! Not bad for a car that weighed 3800lbs+! There's a bit of irony in owning a brand new 1987 corvette, lining up to one of these ominous looking beasts thinking your going to leave him in the rear view, and the BIG dissapointment that a much heavier, cheaper car is now getting smaller in your windshield as you frantically check to see if your car is still running.
It's amazing what the GM engineers achieved, they managed to take a small 3.8L V6, engineer a Sequential multipoint fuel injection, put up to 18psi boost through it, give it longevity and drivability, and still have a decent pricetag.
Our GN had 120,000+ miles on it, we found
Turbo Buick.com learned how to get "free HP" from their forums, we managed to push the stock stuff to a 12.6 @ 96mph w/a 60ft of around 2.2 sec. With the addition of a second fuel pump kicking on at 10lbs boost, an alcohol/water sprayer also kicking on at 10 lbs boost, 83lb/hr injectors, low-imedance matched factory computer, a T-70 w/a .58 turbine housing, "race" roller cam/rockers, ported & polished heads/intake/plenum, HUGE front mount intercooler, larger throttle body, a turbonetics racegate running open-dump, a 3" downpipe into a high-flow cat and 3" dual exhaust. A 9" Art Car holeshot converter turns a 13 vane pump and a shift kit controlls all that HP to the "southside" lower control arms on the rear. Front sway bar is disconnected for better weight transfer through the 10.5" x 32" Mickey DOT slicks.
Last season this car consistently posted 60ft times of 1.5 sec while only being able to launch @12.5psi boost (no trans brake) otherwise the slicks would just go up in smoke, managed a 11.1 pass @ 121mph breaking up all the way down, most likely due to the small .58 turbine housing. Since changing the housing to the larger .96, the car is a bit more laggy, but the upper RPM's don't choke any more (i'm talking about reversion). If we can get the car happy again with this housing I know for a fat that this car is in the high 10's! NHRA rules specify that we already need a rollbar for the times we ran, and we don't feel like hacking a mint interior up so this GN may go back to stock parts and just be a quick stocker.
