Tuesday, January 26, 2010

Vortech Superchargers Turns To Injector Dynamics for Accurate Engineering Data

We were recently contacted by Vortech Engineering to help solve what appeared to be an injector problem.

Their engineers had identified several problem injectors out of a batch. These injectors were triggering the misfire detection in the ECU and setting a check engine light.

Static flow tests showed them all to flow within a reasonable range, but our dynamic characterization showed quite the opposite with a variation of nearly 38% at 2milliseconds.

Once our technology proved its worth to the Vortech engineers we moved on to other projects and were asked to provide the fuel injector "model" to be used in a factory GM ECU.

This amounts to characterizing the injectors at various differential pressures and voltages, and generating 3 dimensional tables that describe the dynamic flow rate of the injector.

Unlike most aftermarket ECU's where we simply adjust the fuel table until the mixture is correct, the OEM's take an entirely different approach.

The ECU determines an air mass based on either a mass air meter, or a VE model of the engine, and then calculates the pulsewidth required to achieve the target lambda value.

As you may have guessed, proper functioning is based on having an accurate injector model.

Especially when you are working to attain emissions certification.

I received this message yesterday, and Vortech was nice enough to let me post it.

"Just got the injectors in the truck that we will be testing and did some preliminary street drive time with the Data that you provided.

Excellent work, with some minor tweaking of the Mass Air transfer function the data from the vehicle is almost perfect.

It does make life so much easier when one has quality data to work with."

Lance Keck
Research & Development
Vortech Engineering LLC

So now that I'm done blowing my own horn, let me take a minute to talk about Vortech. Working with their engineers made it clear to me that they are a company devoted to proper engineering of a quality product.

In an industry filled with BS claims for substandard products, Vortech stands out as a leader who rises above all that by providing a quality product with no BS.

Shane's Tune Getting Too Close For Comfort

This is sure to make a few people nervous.

Shane T does it again.

With very little time spent tuning, at 198mph this car is already uncomfortably close to some long standing 1/8 mile records.

Can You Find Your Pulsewidth With Both Hands?

Well…can you?

Do you “tune” cars?

Do you call yourself a “tuner?”

If so, I have a simple test for you.

Given the following, can you calculate the pulse width required to achieve a target lambda value of .88?

Injector Flow Rate (Slope) = 1032.0cc/min
Injector Offset (Dead Time) = .925msec.
Cylinder Displacement = 38.14ci
Volumetric Efficiency = 92.3%
Barometric Pressure = 28.72in/hg
Air Temperature = 90F
Stoichiometric Ratio of Fuel = 14.23
Specific Gravity of Fuel = .72g/cc

If you can arrive at the proper value of 4.951msec with no more than a calculator and a trip to the bookshelf to look up the formula for air density, congratulations!

You are part of a select few and need to read no further unless you’re just wondering where I’m going with this.

If you came up with the wrong answer, or didn’t even know where to start you need to go see Ben!

Thanks to a guy named Ben Strader, there is a school especially for those who tune electronic fuel injection.

About seven years ago Ben created EFI University to teach the how’s and why’s of electronic fuel injection.

EFI University is more than just a place to go and learn a few things. It is part of a trend.

A trend towards an improved level of quality and understanding in the field of aftermarket fuel injection.

The question is, will you be part of this trend or will you be left behind?