Matt Cramer - Performance Fuel Injection Systems

Table of Contents

We all start off as beginners. While there are some lessons weve learned through practice and experience, there are also many lessons weve learned from others, either by working alongside them on a problem, or by picking their brains.

First, wed like to thank Bruce Bowling and Al Grippo, and many of the members of the MegaSquirt community, who have been so generous in sharing what they know, particularly (in alphabetical order): Jean Belanger, Ken Culver, Eric Fahlgren, Lance Gardiner, Scott Hall, James Laughlin, James Murray, Phil Ringwood, Phil Tobin, and Andy Whittle.

Wed also like to thank EFI tuning wizards Scott Dieselgeek Clark, Chris Macellaro, Ed Senf, and Scott Siegel. A big thanks goes to Michael Lutfy, our editor, without whom this book would never have been possible. And of course to our wives Joy Hoffmann and Kelly Cramer, who put up with us and our automotive obsessions day in and day out.

Finally, wed like to thank all of our customers at DIYAutoTune.com whove supported us over the years. Many times we had to do some careful research and testing to get them the right answers, and over time we realized that somebody needed to write all those answers down in a manner anyone could understand. We hope we have accomplished that and more here, giving our readers the practical know-how and confidence to dive in and make their projects happen.

If youve picked up this book, chances are youre a car nut and a serious DIY (do-it-yourself) enthusiast. The whole automotive DIY movement has returned to fashion in recent years, with a multitude of TV shows, books, magazines, online blogs, and clubs dedicated to the hobby. I have always liked to play with cars. I drive around and see different types of carssome pretty universally loved, and others complete oddballs most would never consider building something cool out ofand I immediately have a vision for them. Whether its an old Ford/Chevy/Mopar just begging for a new fire-breathing small block, or a little lightweight four-cylinder car I can lighten further, add a little boost, and turn into a great corner-carving rocket, Im always looking for new project cars. Ive even been taking a hard look at my wifes minivan. Im pretty sure I can fit a second motor in the rear, turbocharge both motors, and still maintain at least one of the bench seats (after getting her a new one first, of course!). There is no shortage of ideas for what I might do next. I bet many of you have similar visions.

One thing that comes into play with every new motorized toy though, is the need to build an air/fuel induction system that produces maximum performance while maintaining excellent drivability. And maybe, depending on the applications needs, it needs a few more features to help get that perfect launch every time. Or maybe you need to cool the intake charge with a blast of water/meth injection, or inject some nitrous. There are ways to accomplish much of this with a carburetor and a few black boxes, but the performance automotive aftermarket has come a long way since the days where that was the only option. Computer-controlled fuel injection systems are the norm on anything made from the mid- 1980s, and retrofitting EFI to a classic car or truck can enable it to perform better, more economically, and with the best drivability youve ever seen in a classic hot rod. You can ditch the black boxes and have a central point of control for every subsystem on your ride: from basic fuel and ignition requirements to control of a turbos boost pressure, a multi-stage nitrous injection (and the fueling/ignition changes to go along with it), a two- or three-step rev limiter, and many other features. All of these can be controlled from just a single interface, minimizing the pieces of equipmentand therefore the points of failure, in a system packed full of black boxes.

In short, this book is actually a new tool, of sorts, and an extremely powerful one at that. In many cases (depending on your choice of EFI system), it will help you assume full control of every aspect of your engines performance. It will give you the ability to perfectly map fuel and ignition at all load ranges and rpm to extract every bit of horsepower from your motor in all scenarios. This tool is a little more complicated than the screwdriver you may have used to tune carburetors, but its intensely more powerful, giving you a level of control that screwdriver could never accomplish.

Our purpose for writing this book is to remove some of the anxiety many DIYers have when entering the world of electronic fuel injection. Our goal is to present the semi-complex topic of EFI in a practical manner that will allow you to install, modify, and tune an EFI system on just about any motor. In our daily business at DIYAuto Tune.com, weve helped thousands dive into the world of EFI, most without any prior experience, and emerge with a crazy, fun ride to enjoy. So whether youre an old-school carb-guy looking to learn a little bit about this newfangled computer-controlled stuff, an electronics/ computer geek looking for something else to tinker with, or anywhere in between, youll find this book to be a great EFI tool. From the basics to dialing your motor in with the perfect tune, we cover it from a practical angle that will give you the knowledge and the confidence to dive into your next project, which we hope will be the most rewarding one youll ever undertake.

If youre looking for an engineering textbook full of detailed theories and complicated mathematical equations on electronic fuel injection (EFI), put this one down... youve got us all wrong. But if youre the aspiring tuner looking for someone to help you skip through all the bull, get the skinny on what you need to know without getting bogged in the muck, and get a handle on this EFI thing without making you feel like you need to go back to school for a degree in electrical engineering first, keep reading.

The fact is the math and the in-depth theory is good information, but for most of us, its not necessary information. Getting a fuel-injected engine to run well doesnt require you to know how to write control algorithms any more than changing a head gasket requires knowing how to calculate the maximum strain on the head bolts. As long as youre using a reputable product, you can be fairly certain the designers have done their homework and you will just need to get it installed and adjusted right. You can always go back and read up on serious theory later. Our goal is to give you what you need to make it work, and make it work well, without giving you a headache or requiring you to own a calculator with six bazillion buttons. And while a bit of theory is good, it can be taken too far too quicklyyou just want to drive your car!

There will always be some basic math you cant escape from; we cant help you completely escape from all thought and we wont pretend to. Sizing injectors, fuel pumps, etc., are fairly basic principles that well cover to make this sort of thing a snap. But at the same time you really dont need to understand the ideal gas law and associated formulae to install and properly tune your engine management system. So well try not to bog you down in the details. Weve put most of the heavy math off safely in sidebars that you can skip while you read the main text. For those who like having the math where you can find it in a hurry, weve also included all of the equations in an appendix, titled Useful Formulae.