Speed Secrets: Using ZEX Nitrous on a Built 5.3L

On this episode of Speed Secrets, the experts at ZEX. Nitrous is awesome and works well with just about any engine or setup. In this nitrous test, it’s time to give a modified 5.3-liter engine.

If you love nitrous, you’re not alone, so do we. This topic has been covered in depth in several previous videos, and many dyno tests have already been completed, but this time, the subject is applying nitrous to setups that are less than ideal, hoping the juice will make things better.

Originally built for boost, the test engine features low compression heads, a dedicated blower cam, and a short runner high-RPM intake manifold. This engine is a monster when run with boost, but it’s less than ideal when run naturally aspirated – that’s why it’s being used to test nitrous.
The blower cam in the engine is a 54-477-11 camshaft from COMP Cams with a .614/.624 lift, a 227/243 duration, and 114 LSA. The short block is combined with ported cylinder heads. With this setup, the engine makes 465-horsepower and 411 lbs/ft of torque.

By adding ZEX, this combination goes from acceptable, to exceptional. The ZEX wet EFI kit and single fogger is an adjustable system, and has jetting to improve the power output but 125-horsepower. The result is 586-horsepower and 560 lbs/ft of torque – not bad for a simple upgrade!