Carefully slide back the red...
Carefully slide back the red lock tab and then squeeze the factory plug to pull the mass air meter connection off of the sensor. Pull on the connector itself and not the wires.
| RPM | TQ | HP |
| 2,400 | 170 | 79 |
| 2,800 | 221 | 118 |
| 3,200 | 227 | 140 |
| 3,600 | 238 | 171 |
| 4,000 | 251 | 192 |
| 4,400 | 257 | 216 |
| 4,800 | 242 | 228 |
| 5,200 | 238 | 242 |
| 5,600 | 229 | 246 |
| 6,000 | 216 | 250 |
To our surprise, the GMS cold air was worth 13 lb-ft and 11 hp. That's a nice improvement, and we suspect it's due to the smooth contours of the Granatelli inlet tube. Now it's on to the big test-the nitrous oxide pulls. The laughing gas comes on at 2,100 rpm and signs off at 6,000 rpm.
After loosening the clamps...
After loosening the clamps at the throttle body and the fasteners at the air filter enclosure, the whole OE air inlet assembly can be removed.
| Dyno Results |
| RPM | TQ | HP |
| 2,400 | 275 | 133 |
| 2,800 | 303 | 165 |
| 3,200 | 309 | 192 |
| 3,600 | 328 | 230 |
| 4,000 | 380 | 295 |
| 4,400 | 415 | 340 |
| 4,800 | 401 | 371 |
| 5,200 | 371 | 385 |
| 5,600 | 360 | 390 |
| 6,000 | 348 | 391 |
The results show that the nitrous is worth a lot of extra horsepower, 141 to be precise. The torque gain was also substantial at 158 lb-ft. Why the extra 41 hp with the 100 hp jet? We wondered and first thought they might have installed the wrong jet. Then we remembered that, after filling the nitrous bottle, it stood outside in the hot summer sun for hours until we were ready to make our pulls. Of course, a bottle not preheated would produce less horsepower and, to get consistent dyno pulls or quarter-mile runs, the bottle temperature should be kept constant. We did not utilize a pressure gauge on our nitrous bottle, but it would be a wise investment for any nitrous install. All things considered, the GMS Cold-Air Nitrous Kit is a good bang-for-the-buck value that we'd recommend.
 Next, the GMS technician test-fits...  Next, the GMS technician test-fits the new air tube and then fastens it to the throttle body. He leaves the attachment clamps loose enough so that small adjustments can be made. |  Here, the new air cleaner...  Here, the new air cleaner enclosure is being fitted into position. It will be installed using the factory fastener locations. |  Finally, the new air filter...  Finally, the new air filter is installed onto the inlet tube. Once everything is positioned to his liking, the technician will tighten down all fasteners. At this point we were wondering if the Granatelli Motorsports cold-air kit alone would be worth anything over the FRPP cold-air hardware that is OE on the Shelby. |
 At the center of the photo...  At the center of the photo is the GMS air meter calibration harness, which simply plugs into the factory connector and the new air meter. The chip that it contains eliminates any laptop work on the car's computer system. Be sure to engage all wiring connector lock tabs when connecting the wiring. |  Turning our attention to the...  Turning our attention to the trunk area, we found that this plug could be removed and the opening used to route the -4 bottle supply line from the bottle out of the trunk. |  It's nice that we were able...  It's nice that we were able to use a factory opening to route the line rather than cut holes in somebody else's Hertz Shelby. Here, the line is shown exiting the trunk to begin its journey forward to the engine bay. Don't route the line through the interior of the car because a leak could cause the driver to lose consciousness. Route and secure the line under the car while being careful to avoid heat and any moving parts or sharp corners. |