'Pump it-pack it-purge it-squeeze it. Nitrous is the fast way down the track or the quickest path to boulevard stardom. The easiest way to get there is with a carbureted plate system. But who makes the best plate? That's what we're here to find out. We assembled six single-stage plates from as many manufacturers, bolted them on a small-block, and let 'em duke it out. We have average power, peak power, how much each of these plates cost, as well as a ton of other details that you won't find in any other magazine-probably because they're not crazy enough to attempt something like this.
To make it fair, we designed a test procedure where each plate would be run on the same 9.5:1 compression small-block 302 Ford (until it scattered a head gasket). To make it simple, we chose to use one set of NOS Big Shot solenoids and lines along with one 15-pound bottle for each plate. We also specified each plate to run the same-size 63 nitrous jet (0.063-inch diameter), allowing each manufacturer to spec its own fuel-jet tune-up based on a 6-psi fuel-pressure standard. This is a typical tune-up for roughly a 150hp increase.
We started out to test each plate with a full 15-pound nitrous bottle set at 900 psi. We thought we'd test each plate three times between 4,000 and 6,000 rpm and then average the horsepower for each run and combine those three numbers to create a single average power number for each plate that would indicate which plate would be quickest in the car. However, we quickly discovered that nothing stayed consistent even when we didn't change a thing in our test procedure. The runs were often so different that the testing would not have proven anything. So we changed the procedure to average the best run from each plate that could be backed up by a second test that was almost as good. That way, we had some semblance of consistency.
We also carefully monitored fuel pressure, nitrous pressure, air/fuel ratio, and a ton of other variables to ensure that the test was as fair as possible. Pay specific attention to each sidebar. We learned a ton about nitrous in this flog, and we've passed along many of those details that can help you make the most out of your nitrous system.
Nitrous-Oxide SystemsNOS, the oldest and perhaps most prestigious nitrous company in the aftermarket, chose its popular Big Shot system as its plate player. This is a 11/42-inch-thick plate with the standard spray-bar arrangement that has been in use since the early days. The Big Shot plate uses one spray bar for nitrous and the other for fuel, using 34 nitrous holes-the highest count in our test. The holes are drilled at a downward angle to direct the high-pressure nitrous over the fuel to break it into smaller droplets as both are introduced into the manifold. An interesting aside: We found an old NOS plate from the early '80s that had only two nitrous holes per side-four total for the whole plate! This latest adjustable NOS Big Shot system is designed to make as much as 400 hp.
If there were a theoretical advantage, NOS had it because this is the only test where we used the same manufacturer for the plate, lines, solenoids, and bottle. The average power numbers revealed NOS to be right there in the mix with all the plates with the exception of Nitrous Pro-Flow. We also looked at test-to-test consistency, and the NOS plate did well with a difference of only 39 lb-ft of max torque and a mere 11hp difference in peak horsepower between three back-to-back nitrous runs.
By The NumbersPlate: PN 12510NOSPrice: $125.95 (four jet sets included) at summitracing.comJet Combo: 63 nitrous, 71 fuelPeak HP: 598 @ 5,500 rpmPeak HP Gain: 198 hp (400hp baseline)Avg. HP: 559.7$/HP: 0.63Source: Nos (A Division of Holley); Bowling Green, KY; 714/546-0592 (tech); 800/Holley-1, ext. 8530 (nearest dealer); nosnitrous.com