In the staging lanes were the grandsons of America’s quintessential high performance cars — Chevrolet Camaro IROC-Z, Ford Mustang GT, and Pontiac Firebird GTA. In trim they represent the finest examples of total performance ever offered to new car buyers from betwixt our borders. Moreover, for this test we requested the best possible powertrain options for maximum quarter-mile acceleration. We wanted each machine to be as fast as it could be Bearing Firebird GTA badges (from General Motors of Canada) came a bright red 350 Trans Am with 4-speed automatic transmission and optional 3.27 rearend. From Chevrolet we received a black IROC-Z Camaro with 305 cubic inch V8, 5-speed manual trans and 3.45 gearing. The Ford representative was also black, a new GT with red trim, 5-speed gearbox and 3.08:1 rearend ratio.
A surprise guest appeared in the sinister guise of Darth Vader, a much-publicized turbocharged, fuel injected V6 Buick GNX with suspension and engine modifications by ASC/McLaren. In this limited edition configuration (American Sunroof Corp. made exactly 547 GNXs) the all black Regal boasts 276 horsepower (up from the Grand National’s 245 rating), larger wheels and tires, and standard 3.42 rear gears. All the players were ready and the stage was set. It was time to burn rubber in search of the fastest musclecar in America.
BUICK GNX
Not surprisingly, everyone made a dash for the GNX. As the only unknown factor in this menage, we were eager to sample its performance. There are those who may question the validity of the GNX’s inclusion in this performance evaluation. After all, if we can justify a $30,000 hybrid Buick, why not include the similarly priced Corvette as well. The fact is we were hard pressed to justify the extra dough, especially in light of this particular GNX’s lackluster per-formance. But the car was made available to us at the time of this test, and since we were just as interested as the next person to see if it really lived up to its press clippings, well....
In a nutshell, either something was seriously wrong with the production GNX (#002) delivered to us at Norwalk, or everything we’ve heard about it up to this point has been accomplished with a single non-production “test” car. You’re free to draw your own conclusions. Published quarter-mile times in the 13.30s at 104 mph, plus 0 to 60 mph times in the low to mid 5s were the baseline from which we hoped to improve, but after two days and a bunch of runs by three different drivers, the best we could wring out of Darth Vader was a disappointing 13.94 at 98 mph. The quickest 0-60 mph time was a comatose 6.16. With the average ASC/McLaren GNX selling new for $35,000 (and some for upwards of $70,000), it does not get our vote for performance value of the year. But then most people who paid premium prices for these special edition vehicles could care less about elapsed times. The GNX was the last of the red-hot musclecars, and a very collectible one at that.
Despite quarter-mile performance numbers no quicker or faster than the standard ‘87 Buick Grand National tested by our staff last year (SS&DI, Feb ‘87), the ASC/ McLaren GNX looks and handles better than its more generally available cousin. (Although the Buick GN itself went out of production last December, they are still available through used car channels.) Cosmetically, the folks at American Sunroof added fender flares to accommodate big 16-inch, 50 series Goodyear rubber (P245/50VR16 front, P255/50VR16 rear), working fender portholes (remember them?) to vent hot underhood air, and a full brace of cockpit gauges to monitor the SF1 3.8 Turbo V6’s precious bodily fluids.
In a more functional vein, both the turbocharger and intercooler have been redesigned for greater capacity, a ceramic turbine wheel has been added to reduce turbo lag time, the exhaust system benefits from freer flowing mufflers, and a ladder bar has been added to the revamped rear suspension. The result is a sure-footed road hugger that reaches 15 psi of turbo boost in a heartbeat. Another plus is the sure-shifting GM Turbo 200-R4, which has been reprogrammed to provide more positive gear changes. With all of this going for it, our GNX should have dominated its competition at Norwalk Raceway Park. It didn’t. And with the right holeshot, it could be beaten by cars costing half as much.
Buick was just as puzzled over # 002’s flaccid muscles as we were. Ours was the first complaint they’ve received about the GNX..... any GNX..... and in response they checked the car over thoroughly and found nothing to indicate a performance slump. We would have to test another GNX before passing final judgment.
PONTIAC FIREBIRD GTA
The Firebird Trans Am GTA gets our vote for America’s Best Looking Mus-clecar, both inside and out. Where the GNX looks sinister, the GTA appears as if it’s about to launch into upper earth orbit. With hideaway front headlights and a neat rear spoiler, it’s the smoothest F-body ever made. Those of you who’ve read this month’s guest editorial by SS&DI contributor Wayne Scraba know that this red GTA is also the platform for a new volley of street/ strip build-ups rivaling our “Mean Mr. Mustang” series.
Accordingly, it contains the most powerful performance package Pontiac has to offer for 1988; 220-horse, 350 cubic inch (5.7-liter) VS engine with tuned port electronic fuel injection, 4-speed Turbo automatic transmission (700-R4), and optional 3.27. It also has 4-wheel disc brakes and just about every other option known to man. If there’s a penalty to be paid for all for this pampering, it’s in total vehicle mass (our example weighed a hefty 3520 with the gas tank on “E”). Because of this, we would not recommend ordering a Pontiac OTA with the smaller 305 cubic inch (5.0-liter) engine and an automatic transmission. The package might work with a manual 5-speed 305 V8, but the torquier 350 and 4-speed auto seems to be the ideal combination for all types of driving.
Another note: Although Firebirds and Camaros share the same Chevrolet V8 engine packages (5.0 and 5.7-liter), the Pontiac versions are rated at ten less horsepower due to restrictive air inlet systems. Therefore, the 230-horse 350 available in IROC-Zs churn out just 220 in the GTA and Formula Firebirds.
The Pontiac GTA was just as much fun on Norwalk’s twisting return/road course as it was smoking down the 1320. Big 245/50VR16 Goodyear Eagle GTs on 8 x 16- inch cast aluminum wheels worked well in both instances, and the engine provided more than enough torque to exit turns with the tires squealing. This seeming overabundance of low-end torque was tricky to control at the drag strip. The relatively low-geared GTA was quick to strike the tires and yielded widely inconsistent elapsed times. The best pro-cedure was to seriously heat the tires, stage at idle, and just hammer the throttle at the appropriate time, letting the torque converter “flash” to lockup speed for greatest torque multiplication to get the big car moving.
Once on its way, the 350 was allowed to shift automatically and went through the traps midway through 3rd gear. (You can attempt to manually shift the automatic, but strict attention to the tachometer is imperative; the car noses over above 4700 rpm, so it’s important to keep the engine within its torque curve.) In this mode the red GTA responded with high 14-second elapsed times, including a best of 14.71 at 93.65 mph. If you want to go faster, simply order a Formula Firebird with the 350 engine package. You’ll get the same power in a vehicle that’s 170 pounds lighter. Now you’re talking ETs in the mid-14s. If that doesn’t put you on equal ground with the competition, try nitrous oxide.
CHEVY CAMARO IROC-Z
Speaking of equal ground, this is it. Without question, today’s extension of the fabled Camaro Z28, the JROC-Z, is the most popular musclecar on the market. And with the right amount of finesse behind the pedals, it’s also among the quickest.
Super Stock & Drag Illustrated has compared the 305 and 350 cubic inch Chevys before and found as little as a tenth of a second difference separating the two. That minute performance gap was signifi-cant in lieu of past production difficulties with the larger 350. However, now that both powerplants are manufactured in abun-dance, it’s up to the consumer to decide if he wants his IROC with a stickshift or auto-matic (you can only get the 350 with a 4-speed automatic overdrive). Regardless of engine displacement, bottom line performance will be about the same.
When we called the public relations department at Chevrolet and asked for a 5-liter (305 cid), 5-speed IROC-Z for this drag test, our request was met with some reluctance. Wouldn’t we be “happier” with the 5.7-liter IROC? No thanks, we said, the “little” motor will do just fine. And boy, did it ever. For 1988, the 5-liter Chevy (RPO LB9) is rated at 200 horsepower and you can order a 3.45 rearend when specifying the 5-speed manual trans and 4-wheel disc brakes, both of which came with our test car. Before you start shopping for drag slicks to take advantage of all that gear multiplication, be advised that a higher first gear ratio is mandatory with the 3.45 gearset, which gives you 2.75:1 first gearing as opposed to 2.95:1 with the 3.08 cogs. On second thought, get a small pair of slicks, you’ll need ‘em. The stock P245/50VR16 Eagle GTs aren’t quite enough.
While the IROC-Z is a typical all-around musclecar with the looks and suspension to match, the manual trans version is a bit fragile at the drag strip — especially the way we manhandled it at Norwalk. What we thought was a slipped disc in the clutch department actually proved to be over-heated hydraulic fluid. Given a chance to cool down between quarter-mile blasts, the clutch and transmission worked fine. Because of this condition, however, the IROC didn’t see as much ground pounding action as the other three members of our galloping group.
When it did, though, the IROC proved to be up to the challenge. When launched just right, it would s even with the Buick GNX throughout first couple hundred feet. The technique that proved most efficient was to rev the engine up to about 3000 and let the clutch out easy so as to aid lockup and tirespin. Once engaged, we it up to 5000 in each gear and went through the traps at 4200 rpm in 4th gear. This procedure produced a bunch of high second runs, but the best was a 14.7 (94.74 mph) that had us all hooting and hollering. For the first time in our experience, the 5-liter Chevy had outrun the liter in the Pontiac — even if only by seconds! At the scales we learned that of this victory can be attributed to a much lighter fighting weight; our IROC weighed only 3340 pounds with an empty fuel tank.
FORD MUSTANG GT
Because of our familiarity with SS&DI’s own 1987 Mustang LX, we were instantly at home behind the wheel of Ford’s 5-liter GT for ‘88. It’s fuel injected 302 cubic inch powerplant was backed by a 5-speed manual transmission, and the optional 3.08:1 ring and pinion filled the 8.8-inch rearend. Beyond that were a pair of comfortable high back bucket seats to keep both driver and passenger in place during lateral acceleration tests. Highly touted as last year’s leading performance value, nothing has changed for 1988, either inside or out. The Mustang GT’s aero look has been carried over to the new model year, and with it those questionable louvered taillights. But beauty is in the eye of the beholder, and regardless of cosmetics, the GT makes for a nice compact coupe that aches to be driven in a brisk manner. Which is precisely what we did for two days in northern Ohio.
The first series of runs down Norwalk’s 1320 produced the same 95.95 mph trap speeds. though attendant elapsed times ranged from 14.50s to 14.30s. The disparity is easily traced to the little Ford’s broad power band, and its willingness to spin the tires at the first hint of green. It takes practice to work both gas and clutch pedals in perfect harmony, but when all goes right the Mustang CT is tough to keep up with. Before we were finished, it produced the best 60-foot (2.08) and 0-60 mph times (5.96) of all contestants.
Our quickest elapsed times were produced with a driving style very similar to that used with Mean Mr. Mustang when it ran on stock P225/60VR15 Goodyear tires. Rev it up and slip the clutch. Once the pedal was out and the clutch locked up, we rowed the shifter at engine speeds around 5200 rpm. Shifting at 5000 would put us through the traps in 3rd gear, but if we stretched our shift points to 5500, we could pull it into 4th at the first MPH light. Which method worked best depended on the athletic abil-ity of the driver. Our lowest ET, a 14.30, came while shifting at 5500 rpm.
Like the other cars, driving the Mustang GT back down the return road was almost as much fun as going straight. Its firm suspension and nimble stride keep the driver in touch with his surroundings, and the car’s power to weight ratio speaks for itself. It was 250 pounds lighter than either the Pontiac GTA or Buick GNX. And with a list price under $15,000, the GT is once more the best performance buy on the block.
CONCLUSIONS
The most obvious conclusion is that contrary to popular belief, all of these modern musclecars aren’t that far apart on the performance scale. Going into this test we had a fair idea of what the results might be, with exception of the Buick GNX we were basically correct. The 5-speed, 5-liter IROC-Z Camaro edged out the more muscular 350 Firebird GTA, and the Mustang GT outran all but the turbocharged V6 GNX at twice the price. Still, the Mustang’s lead over the others continues to shrink.
Which machine appeals to you depends on your personal criteria and credit rating. They’re all good cars, and they go around corners almost as fast as they run straight ahead. We loved the GTA’s looks, found the IROC’s handling to our liking, and every-one enjoyed driving the Mustang GT. But for all its hype, the Buick GNX was the sole disappointment.
And so ends, dear readers, SS & DI’s Great American Drag Test. We hope you’ll use the accompanying “Fast Facts” guide in determining your next musclecar purchase. We certainly will."
FAST FACTS
SS & DI's GREAT AMERICAN DRAG TEST
