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.
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.