The 1987 3.8L Turbo Grand National. Was it a match for the Stage 1? Let’s find out via “back in the day” tests.
The Buick Grand National and GNX
versus the 1970 Stage 1
Hopefully, we won’t start a fight with this story. For years, the holy grail of Buick performance has been the GS 455 and GSX with the Stage 1 option. It has been proven, with the proper tuning, to run head-to-head with the famous 1973 Plymouth Hemi GTX – a no mean feat.
But let’s also face it, in a “stock against stock” comparison, we assume that the 1970 Stage 1 will kill its 1987 compatriots. But the only way to tell if that’s true is to go back in time to real world tests.
Before we do, however, there’s another point in those tests.
That’s the variables in engine tuning in the muscle car era. Unlike computer controlled engines where there is tight performance “tuning” by the engine computer (and the ability to reconfigure the EPROM for maximum horsepower), the 1970 Stage 1, was a true electro-mechanical and screw driver engine management tool. Spark advance, carburetor jetting and even what was known as “air valve” (spring tension that told the secondaries when to open) could vary as much as 50% in each vehicle delivered. It’s even known that many Quadra-jet 4-barrel carburetors were so mis-adjusted at the factory that the secondary butterflies would only open halfway!
That is one of the reason why there is great variables in testing in those days. The last point in the tests we’ll discuss is tire technology. By 1970 “wide oval” tires were in use, but they were not radial designs, meaning that they did not have the sidewall flexibility to really put the footprint to the ground in hard acceleration, and why most cars ran “cheater slicks” at the drags.
One thing that the 1970s cars may have had an advantage in was exhaust systems – not restricted by catalytic converters, which in the 80s were not like they are today. 80s cars countered that with built in exhaust headers, but the gasses still had to pass through restrictive pipes to exit the car.
Here’s a 1970 GSX going at it with a 1973 GS Buick Stage 1
Buick GS 455/GSX Tests.
Now that the situation has been laid out, let’s take a look at the tests of the Stage 1 cars and get some perspective.
- Hot Rod Magazine’s 1970 Buick Stage 1 Test. The car was a 1970 GS 455 Stage 1 with automatic transmission and 3.64:1 rear gears: Quarter mile 14.40 @ 96 MPH.
- Hi-Performance Cars Magazine 1970 Buick Stage 1 Test. This car was a 1970 GS 455 Stage 1 with automatic transmission and dealer-installed 3.91:1 rear gears: Quarter mile 14.20 @ 100 MPH.
- Motor Trend Magazine 1970 Buick Stage 1 Test. The car was a 1970 GS 455 Stage 1 with 4-speed manual transmission and 3.64:1 rear gears: Quarter mile 13.79 @ 104.5 MPH.
- Hi-Performance Cars Magazine 1970 Buick GSX Stage 1 Test. This car was a 1970 GSX Stage 1 with automatic transmission and 3.64:1 rear gears: Quarter mile 14.00 @ 103 MPH.
Buick Grand National/GNX Tests
Here are two drag tests of a GN and a GNX on street tires and through the mufflers.
- Super Stock Magazine Drag Test 1987 Buick Grand National vs. Mustang LX. The car was a 1987 Buick Grand National with automatic transmission and 3.42: 1 rear gears. Quarter mile time 14.03 @ 93 MPH.
- Popular Mechanics Magazine Drag Test 1987 Buick GNX vs. Callaway Corvette. A 1987 Buick GNX with automatic transmission and 3.42: 1 rear gears GNX 13.40 @ 104 MPH.
Smoke ’em if ya got ’em, The GNX can easily light up those “streets”
So after all that blather, what’s the result?
Take a look. In street trim, the Grand National will consistently run with the automatic transmission GS Stage 1 and the GNX is equal to the 4-speed GS 455 Stage 1 beast!
If you are going to say “but what about with open headers and slicks?”. There the answer may be more telling. The Stage 1 will run in the low 12s . . . but a GNX with that configuration will run in the 11s!
It’s another Urban Legend put to rest.