August 11, 2007

"I'd take that over the Shelby," Associate Editor Mike Johnson says after bursting in my office to return the keys to the Steeda Q335. He was referring to the Shelby GT 500, which we had around the office immediately before the Steeda. That's high praise when comparing this car to the most powerful factory Mustang ever built. Though our optioned-out Steeda tester was in the same fiscal ballpark as the big Shelby's MSRP at $48,261 ($40,545 base with $7,716 in options), it's rated at only 350 hp. Of course, you can buy the Steeda without an insane dealer markup. What's more, the car makes excellent use of the power it has and comes off as a more balanced package. Beginning with a base Mustang GT, the crew at Steeda smiles on the car with a host of handling, power, braking, and appearance mods that transform it from a pleasant car into a grin-inducing driver's car.

Widely known for its suspension packages, the Steeda team makes the most of the Q335 with surprisingly modest modifications. Sport springs lower and tighten to a level we'd all like to see from the factory, while the company's sway bars reduce body roll in concert with robust billet mounting brackets. Meanwhile, Steeda's optional billet lower control arms lighten the unsprung weight while reducing suspension give, thanks to rugged bushings. To the already stiff S197 chassis, only a strut-tower brace and a lower g-load brace further tie the whole package together.

From such a short list of gear, the Q335 delivers the kind of supple responsiveness we've come to expect from Steeda's grippy, streetable packages. Body roll is reduced but comes on a bit as you near the limit, while the overall precision of the steering is greatly enhanced by the more responsive suspension. Ride quality is superb, though it's not quite as cushy as the stocker. Bumpy pavement reminds you there's a solid axle out back; when it's smooth, you'd never even notice.

Inside, the solid axle of our tester was equipped with a set of 3.73 gears, effectively keeping the Q335 in the heart of its powerband most of the time. The five-speed transmission kept the revs at or below 3,000 rpm during my commute, which often creeps up to 80 mph. At some rpm, the standard after-axle exhaust has a slight drone. The general consensus around the office was that it was just right, reminding you when you were on the throttle. Along with the after-axle Steeda mufflers, the Q335 gets a power boost from Steeda's cold-air kit, underdrive pulleys, performance tune, and optional charge-motion-delete plates.

All told, this combination delivers responsive power that pushes you back and revs to the 6,500-rpm rev limiter. As good as the car handles, it's the more visceral feel of the Steeda Tri-Ax shifter that makes the Q335 so much fun to drive. Sure, it can transmit thunk into the cabin if you really bang the gears, but it's so much more precise, it makes shifting something to look forward to. I'd prefer a leather knob to that of the included Steeda billet shift knob, but the metal version didn't keep me from enjoying it. In fact, I didn't even miss Third at the dragstrip with this one, and that's saying something for this part maximizing my modest driving skills.

As much fun as it is to blast up to speed running through the gears or navigate the Q335 through a sweeping turn, it's almost as much fun to squeeze on the brakes. Our tester featured optional 14-inch, four-piston front brakes and whopping 13-inch rears. For those of us who remember pathetic Fox front discs and rear drums that resulted in a white-knuckle, brake-diving thrill ride in a panic stop, the latest Mustangs with big brakes are still remarkable. The Q335 feels balanced and only nudges forward slightly under hard braking.

In all, driving the Q335 inspires confidence. The car responds precisely to throttle, steering, and braking inputs and is a pleasure to drive. We always ask for more power, and we would love to sample the blown Q400. But this car is such a blast, there's not much we'd change about it.

On The DynoNow that we have a slick OBD II interface for our Mustang chassis dynamometer, we're trying to make good use of it on our test 'Stangs. As such, our old friend and former 5.0&SF tech editor/current Mustang & Fords editor, Mark Houlahan, strapped the Q335 to the rollers. Using Mustang Dyno's recommended horsepower at 50 of 13.30 and a vehicle weight of 3,750 for the S197, the peak numbers on the graph-which has more resolution than our chart-were 294 hp and 305 lb-ft of torque. The peak coolant temp was 199, the peak air inlet temp was 93 degrees, and as we've seen with other S197s, the peak throttle opening was 75 percent. The chart illustrates the Q335's nice, wide powerband.

Keep in mind that our Mustang dyno loads the vehicle to simulate actual vehicle weight and aero-dynamics that affect the car going down the road, so these numbers are often lower than the familiar inertia dyno numbers. Even so, to throw in the widely accepted 15-percent drivetrain loss to our numbers, the flywheel number rings in around 347 hp.

To further investigate the car's capabilities, we also popped in our best e.t. and quarter-mile numbers, along with the car's weight of 3,536 (the '07 Mustang's 3,356-pound curb weight plus 180 pounds of Editor Turner) into several online horsepower calculators. Most came up with numbers in the 330 range. We're not quite sure why the Mustang Dyno asks for such a heavy weight for the S197 GT, but if we use the same 3,750 pounds we put in the dyno with our mph, the mph-to-horsepower converters showed us numbers in the 350 range as well. Sadly, we didn't have the presence of mind to actually weigh the car at the track, but as you'll see in the At the Track sidebar, we tried to keep it as light as we could.

It's critical to know all the particulars when throwing dyno numbers around on your favorite message board. Correction factors, vehicle weights, and the smoothing of a graph can drastically affect the numbers, moving them up and down. If you want to learn more about how chassis dynos can differ, check out "Wheels of Fortune" at

2,500 202 97
2,{{{600}}} {{{240}}} 119
2,700 211 109
2,800 241 129
2,{{{900}}} 236 131
3,000 289 166
3,{{{100}}} 209 124
3,{{{200}}} 219 134
3,{{{300}}} 272 171
3,400 236 153
3,500 253 169
3,600 258 178
3,700 269 190
3,800 265 193
3,900 287 214
4,000 262 200
4,100 280 220
4,200 277 222
4,300 283 233
4,400 282 237
4,500 280 241
4,600 280 246
4,700 276 248
4,800 279 256
4,900 275 257
5,000 277 265
5,100 274 267
5,200 270 268
5,300 269 272
5,400 261 269
5,500 260 273
5,600 260 278
5,700 243 265
5,800 242 268
5,900 237 267

At The TrackFortunately, the planets aligned and we had the keys to the Q335 just in time to utilize our test days at Bradenton Motorsports Park ( in Bradenton, Florida, just a short drive from our Tampa offices. Since self-proclaimed hot shoe Associate Editor Johnson was actually busy working on a tech story, I had to suck it up and try to squeeze a good e.t. out of the Q335. It's a tough gig, I know-especially on a sunny spring day.

Knowing the pressure was on, I set out to arrive at the track with just more than a quarter-tank of premium left. That gas is heavy stuff. Steeda already did us the favor of removing the spare tire, as it won't clear the mongo brakes anyway. I also made a quick stop at the convenience store up the street from the track to pump up the front tires to around 40 psi to reduce rolling resistance. Dropping the rear-tire pressure to about 24 psi gives them more of a contact patch. Our Q335 tester rode on Nitto's new Invo tires, which are built to deliver a smoother, quieter ride than the popular 555; they aren't really made for the dragstrip.

After arriving at the track, the engine was heat-soaked after the long drive, so we parked in the shade, popped the hood, and iced down the throttle body, inlet tube, and mass air housing. The S197 has a plastic intake, so we didn't ice that, but we did use a wet towel to cool it after a pass. It surprised us how warm the plastic inlet tube became, so we iced it down. After about an hour, it was time for the first hit. With a nearly 2,800-rpm launch, the car spun slightly out of the hole, then broke loose a bit on the 1-2 shift. It even tickled the limiter some at the top of Third. It had been a while since I'd made a pass. The result was a respectable 13.28 at 105.28.

From there, it was a matter of working out the launch and the 1-2 shift. On the second pass, I just blew the tires away shifting into Second. I hot-lapped it for a 13.42 at 104.99. Then it was time to cool it off again. While waiting, I took more tire pressure out of the rears, taking them down to around 22 psi. On the next hit, I had what I felt was my best launch and 1-2 shift. It was a 2.02 60-foot, and the tires rotated maybe twice on the 1-2. It was a slight improvement to 13.26/104.66, but it was during the heat of the day at 12:59.

After allowing the car to cool while I installed a gut bomb at the local pizza parlor, we came back with high hopes. I hammed up a big burnout for Patrick Hill's camera, then lowered the launch rpm just a tick to 2,600 rpm and landed a 1.97 60-foot time. The 1-2 felt OK, but there was still a bit of spin. The result was a best of the test-13.17 at 105.89. I'm certain this car would easily go into the 12s with drag radials, possibly even with the slightly stickier 555 street tires. That's impressive for a bolt-on car that I drove an hour to the track with the air on and the radio blasting. All I did was restore the street tire pressures and drive the car home.

5.0 Tech SpecsEngine And DrivetrainBlockStock aluminum 4.6Displacement 281ciCompression Ratio9.8:1Crank StockRods Cracked powdered metal with floating wristpins Pistons Hypereutectic aluminumCylinder Heads Aluminum Three-Valve with 33.8mm intake valves and 37.5mm exhaustCams SOHC with variable camshaft timingIntake Manifold Composite shell-welded single runner with Steeda charge-motion-delete plates Throttle Body55mm dual-bore electronic with Steeda throttle-body spacerFuel System Electronic returnless sequentialExhaust Cast-iron exhaust manifolds Transmission Tremec 3650 five-speedRearend 8.8-in w/3.73 gears

ElectronicsIgnitionCoil-on plugGaugesStock w/Steeda white-face overlays

Suspension And Chassis Front Suspension K-member StockControl Arms StockSprings Steeda SportStruts StockBrakes Steeda 14-in Competition w/two-piece rotors and Steeda billet brake duct kitWheels 18x9.5-in Steeda Ultra-Lite Tires Nitto Invo 275/40-ZR18Rear Suspension Springs Steeda SportShocks StockControl Arms Steeda billet lower trailing armsBrakes Steeda 13-in CompetitionWheels 18x9.5-in Steeda Ultra-Lite Tires Nitto 275/40-ZR18Chassis Stiffening Steeda double-bar strut-tower brace, Steeda G-Trac brace