Let Freedom Ring
| | A | B | C | D | DIFFERENCE
A vs. D |
| RPM | Power | Torque | Power | Torque | Power | Torque | Power | Torque | Power | Torque |
| 2,500 | 125 | 262 | 118 | 248 | 130 | 273 | 131 | 276 | 6 | 14 |
| 2,750 | 142 | 272 | 139 | 266 | 156 | 298 | 159 | 303 | 17 | 31 |
| 3,000 | 160 | 281 | 161 | 282 | 177 | 309 | 182 | 319 | 22 | 38 |
| 3,250 | 171 | 277 | 178 | 287 | 194 | 313 | 202 | 327 | 31 | 50 |
| 3,500 | 187 | 282 | 196 | 294 | 213 | 320 | 222 | 333 | 35 | 51 |
| 3,750 | 199 | 279 | 216 | 302 | 228 | 320 | 240 | 336 | 41 | 57 |
| 4,000 | 206 | 271 | 228 | 301 | 244 | 321 | 256 | 338 | 50 | 67 |
| 4,250 | 210 | 260 | 244 | 301 | 261 | 323 | 277 | 342 | 67 | 82 |
| 4,500 | 212 | 247 | 258 | 301 | 274 | 320 | 291 | 339 | 79 | 92 |
| 4,750 | 214 | 236 | 267 | 296 | 275 | 304 | 294 | 325 | 80 | 89 |
| 5,000 | 208 | 218 | 267 | 281 | 281 | 295 | 297 | 312 | 89 | 94 |
| 5,250 | 200 | 200 | 264 | 264 | 276 | 276 | 298 | 297 | 98 | 97 |
| 5,500 | 185 | 176 | 261 | 250 | 271 | 259 | 288 | 275 | 103 | 99 |
| 5,750 | 165 | 153 | 246 | 225 | 260 | 239 | 272 | 250 | 107 | 97 |
A: Baseline test utilizing stock engine with underdrive pulleys, off-road X-shape crossover, a K&N conical filter, and Flowmaster mufflers with dumps.
B: Added Patriot Performance Freedom Series heads, a Steeda Autosports no. 18 camshaft, a Cobra intake, Prime One roller rockers, and BBK long-tube headers with corresponding off-road X-shape crossover.
C: Added a BBK 70mm throttle body, richened air/fuel mixture, and readjusted roller rockers.
D: Added a JLT Performance cold-air kit and a C&L Performance 73mm mass air meter.
When Blow-By Racing's Chris Jones approached us about doing this article, the GT we used for the test featured a Cobra intake, BBK long-tube headers, and an off-road X-shape crossover. We wanted to see what our H/C/I combo was worth versus the stock heads, cam, and intake, so we asked Chris to install a stock 5.0 intake, exhaust manifolds, and an off-road X-shape crossover. During both segments of dyno testing, the exhaust ended with a pair of Flowmaster mufflers utilizing dumps in front of the rear axle. In its stock configuration with the exhaust mods, underdrive pulleys, and a K&N conical filter, the car was surprisingly strong, making 214 hp and 282 lb-ft of torque. True to form, the horsepower peak came about in the 4,700-rpm area, while respectable torque came online around 2,200 rpm and stayed there.
After we installed the heads, cam, intake, and long-tube headers, our first dyno pull was less than we were hoping for with 267 hp and 303 lb-ft of torque. The engine seemed to struggle to build rpm so we started tuning and making mechanical adjustments. Chris adjusted fuel pressure to richen the mixture, and he adjusted the roller rockers. Horsepower improved, but we were running out of tuning options. Chris decided to open the intake tract by adding a BBK 70mm throttle body. These changes started us in the direction of 300 hp with 281 hp and 323 lb-ft of torque.
If a little is good, then a lot must be better, right? Chris further opened up the intake tract by adding a JLT Performance cold-air kit and a C&L Performance 73mm mass air meter. The addition of the cold-air and mass air pushed us over the edge, making 302 hp and a nice flat 344 lb-ft of torque. You don't see it in the dyno chart, but that's because the 302 hp made its appearance at 5,100 rpm on the graph. Mission accomplished.