Preparing Perfect Tuning Results With Proper Injectors, Part 1

The internal combustion engine requires four primary things to run properly: air, fuel, spark, and compression. When you lack one or more of these four, you induce either a poorly running engine or a non-running engine altogether. In a high-performance application, these primary items become very specialized. In the case of fuel injectors, a poorly manufactured or incorrectly sized fuel injector can not only rob an engine of horsepower and cause damage, it can also create a tuning nightmare in the process.

Injector Basics

To understand this scenario better, we first need to look at what the differences are between a cheap eBay injector and a properly manufactured one. While we can all infer an injector is simply the unit that injects fuel into the engine, to a tuner it is much more than that. The injector is the lifeline to ensuring that the engine is going to remain healthy, run optimally, and not have any catastrophic failures that can be pinpointed back to them.

So how does a tuner make a decision on what injectors to suggest? Well, this is based on the factual data that is provided with quality fuel injectors and their preference after years of experience. Quality fuel injectors will include injector tuning data, a pulsed-flow sheet, and come in flow-matched sets. While cheaper injectors will give you a claimed cubic centimeters per minute (cc/min) or pounds per hour (lb/hr) rating, measuring open flow, they don’t usually  provide any injector tuning data, or a pulsed-flow number that could determine variances between each injector. This leaves a gray area that most tuners will want to avoid, as they’ll be spending an exorbitant amount of time trying to create a clean primary fuel table with unknown data. In other words, before ordering injectors, talk with your tuner first and don’t cheap out.

Data Dilemma

Unfortunately for your author, the previous owner of my vehicle had not followed any professional tuner’s advice nor did he bother to research injectors at all. While money was not the cause of his decision, it was clearly a lack of knowledge that led him to a set of 120 lb/hr injectors. Judging by the other faults I’ve found in this vehicle, it’s safe to say he grabbed these based on physical size and claimed flow rate. It’s obvious that he never had  the injectors on a flow bench to verify.

This nightmare quickly became a reality for my tuner and…