There are numerous books that focus on high-performance mechanical mods, but here’s a first – a book dedicated to modification of car electronics systems.
Performance Electronics for Cars gives high-performance enthusiasts an understanding of how their car’s electronic systems operate and details enhancement of these systems using newly released off-the-shelf products developed by the publisher, Silicon Chip.
The content and the products are nothing short of groundbreaking.
In the first chapters, the book leads readers through the basics of EFI and engine management systems – the inputs, outputs and ECU decision making. It also explains the difference between open-loop and closed-loop operating and various other principles that are required to establish an understanding of modifications explained later. It’s all to the point and easy for a beginner to understand.
The modification side of things begins with an explanation of when you might need to make changes and the best way to go about them. Interceptor, chip or programmable management? The book helps steer you in the appropriate direction.
The first 40 pages of this 160 page book are dedicated to understanding car electronic systems, approaches to modification and the equipment necessary to tackle them. Now we get into the Do-It-Yourself projects...
There are 3 instrument-type kits covered in the book – the Smart Mixture Meter, Injector Duty Cycle Meter and a High Temperature Digital Thermometer. The operating principles, construction, calibration and use of each kit are covered in 8 pages on each project.
The Smart Mixture Meter gives you a 10 LED readout of air-fuel mixtures, as derived from your car’s oxygen sensor. While this is a concept familiar to regular AutoSpeed readers, the Smart Mixture Meter adds a very useful function to warn of a potentially destructive engine lean-out – there’s an alarm that sounds at a predetermined lean level and at high engine load. This is a great feature for when all of your attention is focussed on driving.
Next, the Injector Duty Cycle Meter is a handy device for checking your fuel system’s scope for increased power. In a typical situation where you’ve modified your car’s intake and exhaust, the Injector Duty Cycle Meter can be used to see if the existing injectors are operating up to around 100 percent duty cycle (ie they can’t flow any more fuel at that fuel pressure).
Interestingly, the Injector Duty Cycle Meter also doubles as a duty cycle based switching device. It allows you to – for example - activate a water injection system at a predetermined injector duty cycle. Note, however, this is a difficult kit to assemble with up to three separate PC boards required.
The last instrument-type kit is the High Temperature Digital Thermometer. This temperature meter can be used with your choice of a LCD or LED display and is intended for use with K-Type thermocouples. It is rated to over 1200 degrees Celsius (depending on the probe), which makes it suitable for measuring exhaust gas temp, brake temp and all automotive fluid temps. It also has the ability to switch on/off devices on the basis of measured temperature – the switch on/off points can be set separately and the onboard switching relay can handle loads up to 5A. This kit is built on a single, highly-populated PC board – it’s fiddly but achievable.
Each of the chapters on these instrument-style kits contains high quality photographs of the completed circuit board, a parts layout diagram and parts list. The construction of the kit, installation and calibration is explained in relatively simple language. The expanded “How it Works” section is more complicated and is focussed at experienced electronics gurus – but there’s no need to fully understand it to get the kit up and running.
The following five chapters cover kits that have a switching output based on different inputs. The Versatile Auto Timer, Simple Voltage Switch, Temperature Switch, Frequency Switch and Delta Throttle Timer are ideal approaches to switching water sprays, cooling fans, changing transmission mode, a ‘power-on’ delay for power windows and more.
The Simple Voltage Switch, Temperature Switch and Frequency Switch also feature adjustable hysteresis (allowing their switch-on and switch-off values to be set separately). They are relatively easy to build and come with a relay rated at 5 amps.
Probably the most ingenious of the bunch is the Delta Throttle Timer – it doesn’t look merely at a given input voltage, but at the rate of voltage change. This means you can wire the Delta Throttle Timer to your car’s throttle position sensor and whenever you quickly hit the throttle, it triggers an output relay. This relay can be configured to activate an intercooler water spray, switch to the transmission’s ‘Power’ mode or whatever you like. But, remember, it’s not the absolute voltage that’s important – it’s the rate of voltage change.
And now we arrive at the chapters that can potentially change the face of vehicle modification.
The first cab off the rank is the Digital Pulse Adjuster (DPA). The DPA is an interceptor unit intended for use with any pulse-width modulated valve (such as boost control solenoids, idle speed control valves and fuel injectors) and gives the user up 128 points of adjustment across the full operating range. It can be used to drive a valve parallel to any existing ECU pulse signal (to drive an extra injector) or it can be used to intercept and alter an existing pulse signal. There are also some other applications and real-world DPA tuning experiences discussed in this sizeable 13 page chapter.
Note that the Digital Pulse Adjuster is relatively complex to assemble and can be set only via an extra-cost handheld controller – which we’ll discuss in a moment.
The Digital Fuel Adjuster (DFA) operates in a similar way to the Digital Pulse Adjuster, except it modifies DC voltages. As its name implies, the DFA allows you to alter the fuel mixtures of your car by modifying the output of a voltage-type airflow meter or MAP sensor. This simple to use kit looks set to revolutionise the way the average enthusiast tackles ECU mods in their mildly modified streeter. Not only does it allow you to revise mixtures with your existing set-up, it also allows you to change to a bigger airflow meter and/or injectors and realign the load input to achieve the appropriate mixtures. With only one input and output this is simplicity itself, although you must take extreme care while tuning. The kit is also relatively difficult to assemble.
Although intended for fuelling adjustments, the DFA can also be used to alter closed-loop operation by intercepting the oxygen sensor output or to overcome turbo boost cuts (by limiting the voltage from a load sensor). Seventeen pages of the book are invested in this chapter.
The chapter on the Independent Electronic Boost Controller (IEBC) is one anyone with an old-school non-electronic boost control system should look at. The IEBC gives fully programmable electronic boost control with two separate boost maps allowing different peak boost levels and boost curves. The IEBC requires purchasing a suitable 12V solenoid which is pulsed on the basis of injector duty cycle. Unlike any other system we’ve seen, this gives load-based boost control. The IEBC is similar to the DPA in assembly and, again, requires programming via the LCD Hand Controller. Note, however, this one isn’t for beginners – if you’re not completely familiar with the concepts of boost control system, you’re probably out of your depth.
A short chapter is dedicated to the all-important LCD Hand Controller, which is used to tune the Digital Pulse Adjuster, Digital Fuel Adjuster and Independent Electronic Boost Controller kits. Once you purchase and assemble the controller, it can be employed to tune each of the kits – you only need one hand controller. Another chapter gives you a circuit board design that allows the three mentioned kits to be used in any car that uses peak-hold injectors.
Another interceptor covered in the book is the Speedo Corrector. The Speedo Corrector is wired in between the vehicle speed sensor and ECU or between the ECU and speedo. The unit allows you to alter the indicated road speed in 1 percent increments - it’s ideal for anyone changing diff ratio, tyre diameter and correcting the standard speedo error. For the more creative among us, you can also modify the speed input signal for the power steering or transmission control system.
The Nitrous Fuel Controller should be a great way for anyone running a ‘dry’ nitrous set-up to save money and achieve a great end result with regard to the fuel enrichment system. This kit lets you fit an extra fuel injector (or more than one, if required) that is pulsed directly from the unit. The injector duty cycle is adjustable to achieve the correct on-nitrous fuel mixtures. Note that there is no variable input – it’s a constant flow system just like the nitrous supply.
The Nitrous Fuel Controller can also be used to control electric pump and fan speeds (up to 10A). It is a relatively easy kit to build.
The final chapter is on the Intelligent Turbo Timer. This is a particularly clever idle-down system that monitors how hard you’ve been driving in the 7 minutes before switching off the ignition. The unit has an adjustable maximum idle-down period and depending on recent output voltages from the airflow meter or oxygen sensor, it decides on the appropriate idle-down period (which is below your preset maximum). It can also be configured to bypass engine immobiliser systems. This is a relatively easy kit to build and is recommended for anyone in the market for a turbo timer.
Performance Electronics for Cars is unquestionably a groundbreaking book - it details hands-on solutions to electronics-related problems that have largely gone unsolved.
Criticisms? Well, a ‘Difficulty Rating’ would be good for anyone pondering whether to tackle assembling a kit and the layout of the text is sometimes disjointed. There is also no discussion of kit prices and there’s little indication of where they are available from – only a small breakout box in the index page and advertisements on the cover pages.
The price is also a shock for anyone looking to spend some loose change on a magazine – retail price is AUD$19.80. Fortunately, it has the feel of a high quality publication – its square-bound, there are plenty of vehicle manufacturer diagrams, coloured diagrams and quality all-colour photography.
And as we keep saying, the content is also ground-breaking.
Footnote:Performance Electronics for Cars is co-authored by John Clark and Julian Edgar. Julian Edgar is a major contributor to AutoSpeed.