To a rare handful of car nuts cracking ECU codes is as easy as cracking walnuts, to most it can be an endless guessing game. Playing with a cluster of numbers and letters that resemble a string of genetic codes more than electronic codes can push mere mortals to the brink of insanity. While the idea of programming a herd of Holstein cattle that can accelerate from 0-60 in four seconds flat has merit on some level, let's stick to the details. At its core, reprogramming a factory ECU requires deciphering electronic code and modifying that code into a chip that must be either soldered into the board, via breadboard, or if you're lucky, the chip can be a quick and easy plug-in proposition. Link ElectroSystems has re-written the book on ECU tuning.
The latest electronic wizardry from Link is its plug-in programmable ECU motherboard. One can basically think of it as a plug-in stand-alone tunable engine management system without a myriad of common stand-alone pitfalls. The Link ECU is a complete circuit board that replaces the car's factory motherboard. So do we have your attention now? Is your mind swamped with interesting technical questions? Well don't fire up the e-mail yet.
Is there absolutely no external wiring?The base package is designed to plug into the factory harness as well as run off of all the factory sensors. Link has deciphered and translated all of the OEM voltage signals to work with its ECU, so there is no need to hard wire any sensors with the base package. There are options that can be externally wired into the unit. Installation requires unbolting the factory motherboard out of the ECU case and replacing it with the Link plug-in board.
What if my car is turbocharged?The ECU also has the option to run a forced-induction fuel and timing map. By selecting "LIMITS" in the main menu, you have the ability to change your fuel and timing map for a boosted engine. Not only does the unit allow you to run up to 8 pounds on the factory map sensor, you also have the option to run a larger plug-in map sensor. The optional map sensor is capable of reading up to 30 psi of boost and it is a direct replacement for the factory unit. Both the fuel and timing graphs are read in kPa, so changes made to the size of the mapping should be converted from psu to kPa.
Does the unit require a laptop?Link has two different methods of tuning, a hand-held programmer or by laptop. Both the hand-held and laptop features are plug in, but do not come as part of the package. Of course base tuning will be required for a car's own personality, but tuning parameters should be accessed by a Link dealer.
The hand-held programmer is able to access every menu bank the system has to offer. Scroll by using the "SELECT" up and down keys will get you through the main menu and scrolling "EDIT" up and down will allow entrance within particular tuning parameters. Adjustments are made by using the "ADJUST" keys, which work from left to right.
Although the programmer allows access to all menus, it can also be replaced with a laptop by an optional Serial Link or Data Trap. The Serial Link replaces the hand-held programmer and allows access by laptop. By using a laptop, you can view more tuning cells and see further into the programming by monitoring maps from a numerical standpoint or in 3D. Using a laptop also allows you to scroll through your fuel and timing parameters much quicker than the hand-held programmer.
Another handy option that can be used with the laptop is the Data Trap. The Data Trap can datalog up to 73 minutes of engine output and input information.
Does this unit allow you to monitor real-time sensor readings?Viewing sensor status can be monitored as actual voltage signals pass through the ECU. This allows you to check if a sensor is actually functional and working properly. All of the basic functions can be monitored from engine rpm, water temperature, O2 voltage, battery voltage and injector duty cycle. When the Link unit is initially plugged into the car's ECU harness, it is necessary to check if all sensors are reading correctly.
How much resolution does the fuel and timing tables have?Zone fuel and zone ignition can vary depending on the type of map system you set the ECU to. The mapping can vary from 96 to 192 cells for fuel and the same count for timing. The zone tables are broken up into number values and these numbers will determine which zone you are in when programming. While each zone can be determined by its number value, the engine's rpm and kPa can be tailored to what the engine requires (e.g. boost or vacuum). This varies by entering either "MAP," "MAP/TPS" or "VACUUM" mode into the ECU.
"MAP" mode reads 96 cells for vacuum, atmospheric and boost for fuel and 96 additional cells for timing. While in this mode, the cells are broken up into rpm and boost. The amount of boost that the car will push determines the size/resolution for mapping operation parameters.
If the ECU is programmed for "VACUUM" mode, then both fuel and timing tables will be set for normally aspirated engines only. Sizing will still be 96 cells for both fuel and timing tables, but the resolution will have been increased due to the vehicle staying in normally aspirated trim. For instance, let's say we have a car that boosts 8 psi and revs up to 8000 rpm, the first two horizontal rows will read vacuum, the third will read atmospheric and the last three will read under boost. In normally aspirated trim with the "VACUUM" mode selected, we would have five rows of vacuum and one for atmospheric.
The last option is to select mixed mode, which provides even greater resolution for boosted powerplants. By choosing mixed mode, you have the ability to toggle between "TPS" mode and "MAP" mode, doubling the tables available for tuning. The addition of "TPS" mode will result in better idle and throttle response while using the "MAP" mode for most of the boosted zones for fuel and timing.
What options can I add to the unit?Some of the upgrades require additional pre-programming or programming with the hand-held controller. A few of the upgrade options include the ability to control boost, individual or waste spark ignition and wideband O2 sensor programming.
Not only is the Link computer able to control a forced-fed engine from a tuning standpoint, it can also be used as a boost controller. Staged boost is yet another option that can be added to this engine management system. Plug a boost solenoid into the factory harness and boost pressure can be controlled in 16 stages by rpm, ranging in 500-rpm increments up to 8000 rpm.
Just like most stand-alone management systems, the Link motherboard can also convert your normal distributor-type ignition into a distributorless ignition system. Whether you desire a wasted spark system or full-blown individual coil system, the Link ECU is capable of making it happen. By adding one Link igniter module and two dual post coils the Link ECU will allow a wasted spark mode. Individual coil mode requires two igniter modules and four individual coils. Trick.
The Link unit comes with O2 sensor correction programming, but the factory O2 sensor(s) will not correct for rich ratios (lower than 11.0 to 1). If a user wants to tune a powerplant, his only options are to either weld an additional O2 bung on the exhaust header or downpipe for tuning or remove the factory unit in place of a wideband sensor for tuning. After tuning is complete, the factory O2 would be placed back into the exhaust system. With the Link ECU, the tuner has the ability to replace the factory O2 sensor in favor of a wideband O2 sensor. Of course, one would have to recalibrate the voltage signal for the new sensor, but this handy option increases the overall tuning versatility of the system.
All in all, the Link motherboard is the best tuning option this side of a full-tilt stand-alone system. Whether the car is a full-blown race car, extreme street car or just a more typical street prowler, the Link ECU motherboard can eliminate aftermarket wiring harnesses and additional non-plug-in type sensors and deliver a fully tunable landscape for under $1,300. This is a hard-hitting, far-reaching technology considering that installation, in some cases, requires only a Philips screwdriver and a 10 mm ratchet. As Link's applications list grows, this system may well prove a viable option for savvy hands-on tuner/enthusiasts. But are the cows safe?