Don't think SVT just popped...
Don't think SVT just popped an oil pan on the Ford GT block and called it a day. Much like the car itself, the block received numerous detail improvements. Those upgrades include reinforced structural webbing, six-bolt billet main caps, larger oil drainbacks, and an integrated windage tray. Of course, the big improvement is the Plasma Transferred Wire Arc cylinder liners which work with a unique block machining process to produce an engine that is lighter and more efficient than an aluminum-block with steel liners.
In practice, we couldn't agree more. Turn the key and the GT500 emits a pleasant, throaty rumble to the rear. Quiet by our standards, because SVT's engineers strived to reduce road noise by a whopping 20-percent. Sadly that also means the supercharger whine seems further dampened in the cabin, even when the 5.4 is ripping at full song. Before getting to that point, the tweaks in the car's clutch and even the car's footbox resulted in a clutch feel that's a bit more apparent than the '10 version, but glass-smooth compared with the '09-and earlier-variant. Naturally, the 3.73s in the Performance Pack are a happy addition that get the car moving and keep it in its comfort zone, riding 80-percent of its torque from 1,750 to 6,250.
On track at Virginia International Speedway, we were able to make single laps in both standard '10 GT500s and '11 GT500s equipped with the Performance Pack. It would have been illuminating to have an '09 there too, but the '10 proved a good baseline. Under my clumsy control, I quickly found the edge with the '10. Upon swapping into the '11, I tried to maintain that first-time-on-the-track pace for the first lap or slow, then increase speed. As expected, the edge was further out with the '11, and it exuded more confidence on track. There's nothing like having the car rolling under full boost and suddenly reeling things in under braking, and have the car just do it without complaint.
Much like the '11 GT, the...
Much like the '11 GT, the engine is only part of the story with the '11. While the convertible gets brought up to par with the coupe, the Performance Pack takes things to another level with springs that are 20.5-percent stiffer in front and 9.5-percent stiffer out back. These coils are also shorter by 11mm and 8mm, respectively. Stiffer sway bars and revised brake backing plates that improve cooling are among the other detail improvements under the car.
We also couldn't complain about our duty upon leaving the track. From lapping VIR in coupes, we shifted gears to road-tripping in a convertible from Virginia to Florida. Stepchild no more, SVT engineers promised the convertible was as good as the '10 coupe from a chassis-rigidity standpoint, and when equipped with the Performance Pack, it certainly didn't seem to give up any handling either. More impressive, the car really doesn't give up much ride quality. After several long stretches in the driver seat, we weren't clamoring to get out from behind the wheel.
Sadly, getting out from behind the wheel came sooner than expected. Not surprisingly, the latest GT500 is a tough habit to break. Lighter, more agile, and ready for street or track, the Performance Pack Shelby sets a lofty bar for its descendants. We look forward to seeing how they stack up.
On The Dyno
Dynojets are remarkably repeatable unit to unit, so we really only had to factor in the differences in weather conditions
Having had a '10 GT500 on the dyno at VMP Tuning (www.vmptuning.com) last July, we thought it was worth comparing to the '11 GT500 to see how that extra 10 hp at the flywheel translated. We didn't get a chance to get back over to see Justin Starkey at VMP again, but we do have our own shiny new Dynojet (www.dynojet.com) chassis dyno here at 5.0&SF world-domination headquarters. As such we dyno'd the car in our shop and sent the file to Justin so he could put the '10 pull on the same graph as the '11 pull.
Dynojets are remarkably repeatable unit to unit, so we really only had to factor in the differences in weather conditions. We use SAE correction, which can compensate for some differences, but our barometric pressure was pretty low at 29.54 in-hg versus the 30.19 in-hg the 2010 ran in. As such, our boost was probably impacted, but Justin said the correction could have been a little aggressive with that baro. We'll chalk that up as a wash, as the uncorrected numbers on our pull were only a few ponies higher. Our '10 GT500 also ran in warmer more humid conditions, so this isn't pure science, but it does show the latest car is packing a little more muscle underhood. Perhaps it's even more than 10 at the flywheel ...
At the press launch, we were...
At the press launch, we were fortunate enough that Ford set up the first media drive on the full course at VIR. The only difference was a coned chicane in the middle of the big straight. I started out in a standard '10 GT500, which I thought was pretty great last year. Then I moved into the '11 GT500 with the Performance Pack. It was a substantial improvement in my estimation, but SVT's test driver Gene Martindale wheeled the '11 PP GT500 around the track 3 seconds quicker than the '10 GT500, which is an impressive feat.
It's the things you can't...
It's the things you can't see or won't notice that contributed to the extra 10 hp, but what immediately distinguishes the '11 Shelby GT500 from its predecessors are the silver supercharger and blue cam covers-a configuration hinted at by the silver blower on the Patriot Edition '10 Shelby GT500 ("Patriot Game," April '10, p. 42). The additions really brighten up the engine compartment.
Bill Sheffer and Matt Thomas...
Bill Sheffer and Matt Thomas built this supercharged 5.4-liter beauty under the hood of our test convertible. Eagle-eyed GT500 acolytes will notice something "missing" here. That's right-with the addition of Electronic Power Assist Steering, there is no longer a power steering fluid reservoir bolted to the cylinder head.