Nitrous on Chevy Small Block - Dyno - 'Round The Outside

At The PlateAs we mentioned earlier, Zex's Perimeter Plate System seeks to harness-and focus-the energy created in the very act of injecting nitrous into an engine. According to Zex's Matt Patrick, this approach provides a number of benefits. "On a typical 425hp small-block," he explained, "We'll see an exhaust gas temperature (egt) variation of up to 60 degrees. It's inevitable that some cylinders get more air/fuel mixture than others." Perimeter Injection, he told us, evens out this distribution-so much so that the maximum temperature variation comes down to 30 degrees.

There are two other benefits to this setup, Patrick explained. One is that the nitrous' trip through the system helps "super-chill" the plate, a process Zex calls Cryo-Sync Technology. This process also cools the carburetor and intake manifold, he explained. And as you know, a colder charge is denser, and carries the potential for more power production.

The last feature, Airflow Enhancement Technology, refers to the low-pressure area created by the Perimeter Plate spray pattern. The nitrous is injected at a carefully designed angle, toward the center of the intake plenum. This pressure differential, we're told, helps pull more air/fuel mixture into the engine, creating even more power.

We can't say if the Perimeter Plate System works better than a traditional spray-bar setup, since we haven't tried one on this particular engine. We can say, on the other hand, that this particular nitrous setup was a great match for our engine combo.