Tested: 2005 GTO

Before we wrote last year's review of the '04 GTO, the GMHTP staff made several suggestions regarding ways GM could improve the car for 2005. We voiced those opinions in our review of a Torrid Red six-speed ("Great Expectations," Jan. '05), and hoped that GM had similar changes in mind. I'm very happy to report that, despite the still-rubbery shifter and absent interior door lock switches, the Pontiac GTO has moved from the very good '04 model to a truly outstanding '05 GM product.

Here are the highlights:
*The 364-inch LS2's 400 hp and 400 lb-ft of torque is readily apparent compared to the LS1's 350/365 power rating

*The '05's bigger 12.6-inch front brakes are a huge improvement over the '04's 11.7-inch front rotors

*The regular '05's hood, rear fascia, and exhaust changes are much more attractive and aggressive than the '04 model's look

*Electronic throttle control is smoother and more precise than the throttle-cable LS1

*A revised traction-control system has no throttle "kick-back" and allows more wheel slip before intervening

*The driveshaft, ring-and-pinion, and CV joints were strengthened to better handle the LS2's power

*Wheelhop, which was a serious problem on '04 models, has been reduced significantly for '05 GTOs

And if you still think that the GTO is too demure, Pontiac has you covered with the "Sport Appearance Package" option. This dealer-installed kit is available for Torrid Red (RPO NBA), Quicksilver Metallic (NBC), and Phantom Black (NBB) '05 GTOs for an additional three grand. That extra dough buys different front and rear fascias, side rockers, grille inserts, and a more angular rear spoiler. Installed underneath that new rear fascia are different mufflers and exhaust tips.

This June, the GMHTP staff had the opportunity to dyno and track-test an '05 GTO with the RPO NBA Sport Appearance Package. The cool-looking grille inserts hadn't been installed before these photos were taken, but we were more interested in the brand-new LS2's power potential, anyway. Rumors abounded that the LS2 and the LS6 were totally different beasts, and it was said that despite being up on cubic inches and compression, the LS2 didn't have the edgy, high-strung power of its older Gen III sibling.

That ended up being true--on the same dyno where we tested a '04 Z06, this GTO's LS2 was down 22 hp and 13 lb-ft of torque compared to the Vette's LS6. However, this Corvette versus GTO test didn't allow us an apples-to-apples comparison regarding drivetrain efficiency; if it had, these numbers would probably be closer.

Pontiac's GTO finally got an engine to match its considerable weight. The 6.0L/364ci mill gets that displacement from a 4-inch bore and a 3.62-inch stroke. LS6 heads, a redesigned intake, 10.9 to 1 compression, and a 204 /211 degrees at .050, .525-inch-lift cam combine to produce an advertised 400 horses and 400 lb-ft of torque.

But a dyno can only tell part of the story: Old Bridge Township's Raceway Park would have to tell the rest. Those of you who read our '04 GTO track test might remember the 86-degree temps we tested in. I was able to muscle the 350-horse '04 Goat to a 13.40 ET that day--it was warm, but low humidity kept things bearable.

On June 28, 2005, you could look at the Northeast's weather pattern in two ways, as that Tuesday ended up being dry as a bone; it was great considering the monsoon--like rains New Jersey received the day before and the day after. And the temps were similar to last year's GTO test, just under 90 degrees. But the humidity--a sticky 85 percent--was downright oppressive. It was the most miserable track day I could remember in the four years I'd been here; by the time the track was fully prepped at 9:45, the heat was there to stay--and the LS2 really had its work cut out.

RUN 1, 9:53 a.m.
The GTO had a full hour to cool off before the track was ready, so editor Scott Parker and I occupied ourselves by double-checking the lug nuts and tire pressures and icing down the LS2's new intake. When the time came, I strapped myself in, threw on the Simpson, and adjusted the seat for a better feel of the pedals. I turned the Goat's massive key and the LS2 sprang to life, the Sport exhaust emitting a delicious burble. The traction control button was pushed as I pulled up to the water box, and a big Second-gear burnout filled the air with smoke as the tires grabbed and I shot to the starting line. For the first run I dialed up a conservative 2500 rpm. When the tree came down I let the clutch out, the car slightly hesitated before I added more throttle, and a 2.10 60-foot flashed on E-Town's big clocks. The LS2 pulls quicker than the LS1, and I banged Second in no time. The Pontiac really started moving, and the Two to Three shift was made with the tach needle dancing near the 6500-rpm redline. I wound out Third, slammed Fourth just before the finish line, and the boards lit up with a 13.30 at 106.04.

The big LS2 responded with 341.1 horses at 5852 rpm and 333.9 lb-ft at 4565 rpm--check out the flat-as-Iowa torque "curve"! Those solid rear-wheel numbers were created with 24 degrees of WOT timing and GM's signature 11.8 to 1 air/fuel ratio. Taking those numbers and factoring in a 13 percent loss, the GTO's LS2 makes 392.1 hp and 383.8 lb-ft at the flywheel.

RUN 2, 9:56 a.m.
I immediately pulled back around for another try, and after a quick spin to clean the tires off, the GTO was back in the stage beams. As I was accustomed to launching the 365 foot-pound '04 model at 3100 rpm, I decided to dial up 3 grand to test the IRS's patience. When the clutch came out the LS2's big torque contorted the GTO's independent rear suspension, and the wheelhop was so bad that I aborted the run.

RUN 3, 9:57 a.m.
The perfect launch rpm was somewhere between the bogging 2500 and the hopping 3000. As the big LS2 was getting warm, I wasn't expecting a great ET out of this run. But before parking the GTO for a cooldown, I experimented with a 2800-rpm launch--and again, just enough wheelhop surfaced to create a poor 2.17 60-foot time. I knew the clocks would frown on this attempt but ran it through anyway. Result: 13.51 at 105 and change.

RUN 4, 10:25 a.m.
After a half-hour cooldown, I again rolled up to the line and got the BFG 245/45-17 radials hot and sticky. This time, 2500 rpm was showing on the tach when I let the clutch out, but I applied a little more throttle to assist the 3,890-pound Pontiac off the line. The GTO's IRS doesn't like throttle input when the clutch is coming out--the rear shook a bit, with a 2.12 60-foot as the result. Even though the short time wasn't stellar, the LS2 must have enjoyed its short break, as it powered through four gears to turn in a 13.37 at 105.64 mph.

RUN 5, 10:28 a.m.
As the track temp continued its relentless march upward, the clutch/launch rpm combination was starting to come together. Twenty-five hundred was too low, 3000 was too high, and breathing on the throttle while leaving was a definite no-no. So after smoking the 17s, I gently eased into the stage beams and requested 2700 rpm from the Goat's electronic throttle. When the tree came down I reduced pressure on the clutch as to allow it to smoothly and quickly push my leg back, and the GTO was out of the hole with a solid 2.08. All gears were changed smoothly; even though the warm Gen IV mill could only muster a 13.41 at 105, we were on to something.

We wanted to verify those power numbers, and once again, SLP Performance Parts in Toms River, NJ, donated some dyno time. The exhaust system was tapped for a wideband O2 sensor, and a scanner was plugged in to pick the new ECM's brains.

RUN 6, 11:44 a.m.
I'd found the sweet spot for launching Pontiac's 400-horse GTO, so Parker and I figured it was best to give the car a nice long break. Just before noontime I pulled to the line again and duplicated the previous launch. And it worked: Despite the fact that the line was starting to go away, the 60-foot time dropped again, to 2.06. After I worked through the Tremec's first four gears, the LS2 responded big time with a 13.24 at 106.

RUN 7, 12:41 p.m.
A check of weather.com told us that we'd reached 88 degrees by 12:30. The mixture of heat and thick humidity made the area around E-Town's starting line--normally the BS spot on these track days--empty, save for one extremely hot starter. The ice bags we'd placed on the LS2's intake were now filled with lukewarm water, and the big motor still had heat in it from the last run. We gave it 10 more minutes to cool down, then I again called the all-aluminum Gen IV to battle.

The Sport exhaust's tone changed from burble to scream as I wound the LS2 to five-grand and smoked the hides. Once traction caught I was yanked toward the line, stopping quickly when the big four-wheel discs were activated. I pushed in the clutch, selected First, and lit the pre-stage bulb. Light clutch action was needed to just trip the stage light, and a touch over 2700 rpm was dialed up. Yellow, yellow, yellow...

The '04 Goat's extreme wheelhop was fixed for '05, but the LS2's increased power only allowed around 2700 rpm during launch. The day's best recorded 60-foot time was a 2.06.

I knee-jerked the clutch and caught traction after a brief spin, 2.07 flashed. First's 2.97 ratio met the LS2's redline immediately, and the soft clutch still had enough grip to chirp Second. The cabin began to fill with that great baritone sound as the 2-3 gear change was made, and the timing clocks registered an 8.60 eighth-mile time at nearly 85 miles an hour. There was only one gear left, and with the clocks and redline approaching, I threw the rubbery shifter home and crossed the stripe. 13.20 elapsed time, 106.84 miles an hour.Four more runs were made, all in the 13.30 to 13.40 range, but the track went away by mid-afternoon. The 13.20 stands as the best time of the day--a day in which GM's GTO fought through crippling heat and nearly two tons of weight to make an impressive statement.

Some loyalists still scoff at its IRS, a suspension that yields huge dividends on the open road but isn't beefy enough to 60-foot like the F-body's old live axle. And this GTO can't honestly be called a solid 12-second car--although it may have been possible in cool conditions, the Goat will need another 30-40 horses before it clearly surpasses a Fourth-Gen LS1's drag times.But when you get right down to it, this car is much more rewarding than the '98-02 F-bodies. Stock horsepower and torque is unbelievable, especially around town and on the highway. The body doesn't creak, the fit, finish, and material selections are high-quality, the seats are killer, and it is quiet and composed over the worst roads. Regardless of what GM designs to get back into the pony car wars, it should take as many pages as possible from the '05 GTO's book.

We like everything about the Sport Appearance Package except for the flat rear fascia. The mufflers with this package give off an outstanding crackle on the overrun.	These 17s are a carryover from '04; for '05, the binders underneath have grown from 11.7 to 12.6 inches--stopping power is excellent.

PERFORMANCE TESTING EXPLAINED
GMHTP gets lots of inquiries regarding how the editors test new vehicles. Here are the details:

* Vehicles are bone-stock, the air filter is not removed
* The factory spare tire, jack, tools, and interior pieces are not removed
* Test tire pressures are manufacturer's spec
* A half-tank of Mobil 1, BP, or Sunoco 93-octane fuel is used
* A burnout is performed prior to staging
* Manual-trans vehicles are powershifted
* All published times and speeds are uncorrected

RACING TIPS--'05 GTO SIX-SPEED
* Unlike an LS1/LS6, the LS2 is very sensitive to engine temps and doesn't respond well to hot-lapping
* The LS2's torque advantage over the LS1 means that launch between 2500-2700 rpm work best, depending on track prep
* The GTO's IRS responds well to a "knee-jerk" launch action-- not exactly a wheelhop-causing sidestep, and not a clutch/gas slip
* Be sure to keep those burnouts straight--if one wheel stops spinning you could hurt the factory posi unit
* The stock shifter can make the 3-4 shift difficult

BRUCE ALMIGHTY
When GMHTP gets a GM press vehicle, we usually get about a week of driving and testing in before it gets returned to the General. The Torrid Red '05 Goat you see here isn't one of GM's press vehicles--it belongs to Wisconsinite and all-around good guy, Bruce Corcoran. You see, it's always fun beating on other people's cars, so in late 2004 we put out the word that we were looking for a new vict...project to test and build-up in 2005.The terrific staff over at Todd Wenzel Chevy-Pontiac-GMC in Hudsonville, MI (www.toddwenzelchevy.com, 800/321-5515), pulled some strings to get us connected with Bruce, worked out some details, ordered this '05 GTO, and installed the NBA-code Sport Appearance Package before delivering the car to us in New Jersey with a scant 52 miles on the clock. Their customer service has been top-notch, and we'd like to give them a big thanks!Bruce was kind enough to let us keep his new Pontiac for a few months--it takes a brave man to flip the keys of a brand-new car to us track monkeys. We'll repay him by modding the LS2-powered GTO to within an inch of its life before we give it back. The parts are on the way and the AAA Plus membership is paid up--let the hot rodding begin.