Forget the promises of an "ownership society" in which a little elbow grease can get you to the top. Despite all our hard work, some of us just never seem to get our big break. The reality is that we live in a world of "haves" and "have-nots" and until recently only the "haves" could afford the latest engine management. The rest of us were forced to either mortgage the house and eat instant Ramen for six months to finance a full stand-alone or run a hodgepodge of rising-rate fuel pressure regulators (FPR), timing retard devices and/or a series of piggybacks. Pretty lousy options, if you ask us.
The disadvantages of an expensive stand-alone ECU are obvious, and when you start adding up the costs of multiple piggybacks, you might as well start looking at stand-alones again. The hodgepodge option isn't any better. Its components are not feedback controlled and are instead adjusted at WOT and full boost to provide the correct mixture/timing to ensure maximum efficiency and minimize the likelihood of detonation. The problem is that they're mechanical and only set to be optimal at one point-WOT in this case. Driveability will often suffer everywhere else. And seriously, how much of your commute is pedal-to-the-metal driving?
If you check out some low-dollar turbo builds, it's a sure bet you'll find more than a few rising-rate FPRs. These babies are what initially made aftermarket turbocharging such a magical endeavor. These were probably pretty groovy pieces back in the mid '70s when they hit the scene, but hey, so were bellbottom pants. These disco-era wonders work by increasing fuel pressure as manifold pressure increases. This means the injectors are open for the same amount of time whether the boost is at two psi or 10. Under boost, the additional fuel metering isn't controlled by the ECU, but by the rising-rate FPR that couldn't care less what the current A/F ratio may be. The beauty of fuel-injection lies in its ability to accurately deliver exactly the right amount of fuel, under all possible operating conditions. Now, why would we want to screw that up with a fixed mechanical device the stock ECU can't compensate for?
The spark timing solutions that often went hand-in-hand with rising-rate FPRs were just as barbaric. Again, there were only a handful of options and many people resorted to a base timing retard or a manifold-pressure based timing retard unit. The former has obvious problems such as sluggish off-boost performance and higher EGTs, while the latter suffers from the same problems as the rising-rate FPRs-no feedback (knock detecting ability). With the lack of feedback from a knock sensor, your engine could be pinging itself to death and you might not even know it.
None of these options are ideal-especially when you consider that forced-induction engines need precise fuel and spark control to help avoid detonation. A much better solution is one in which the fuel pressure remains as it would in a stock application and the ECU calculates-based on input from various sensors-the required fuel and sends the appropriate signal to the injectors to match the desired A/F ratio-a true feedback system.
Seeing this need for affordable engine management, GReddy designed the original e-manage. The unit was a piggyback EMU, meaning it was wired into the stock ECU, used all original sensors and allowed for full control of the injectors-among many other things-based on feedback from a wideband or traditional 02 sensor.
Users could make adjustments to their stock ECU's fuel map at every possible rpm and load zone. This meant low-budget tuners could finally ditch their rising-rate FPRs and move one step closer to the power and driveability that full fuel mapping offers. On top of fuel control, the unit offered a myriad of other features and in/outputs. It even allowed ignition-timing control with the addition of an extra harness. But again, this added additional wiring work and costs.
While none of this has ever been any concern of the "haves," there is undoubtedly more than a few of us who have endured the hardships old-school setups create. For us, it's been a long and arduous road, riddled with the carnage and destruction of lackluster fuel management and indifferent ignition timing, but good news is here.
There is now a widely supported, feature-laden programmable piggyback EMU that gives full fuel and spark mapping, knock detection and on-board data logging, just to name a few of its multitude of functions-all at a cost us "have-nots" can afford.
GReddy's latest incarnation of its e-manage EMU gives users the ability to re-map both fuel and spark curves without extra parts. The e-manage Ultimate has further narrowed the gap between stand-alone and piggyback engine management. This means tuners on a budget no longer must choose between paying the rent, or risk snapping their rods and frying their pistons.
However, if you plan on running higher boost and/or more aggressive fuel and spark maps, you may be pushing it. While the e-manage can detect and log detonation events, it will not pull timing when it detects them-most stand-alones will. You must go into the e-manage's tuning software and manually remove ignition advance in the zones in which it occurred, repeating until the knock disappears. These are just a few of the many things you should consider when choosing engine management for your freshly boosted engine
While the difference in cost (with an MSRP around $800, versus upwards of $2,500 for many stand-alone ECUs) may be the overriding factor when choosing engine management, the most expensive and complex isn't always the best solution. There is a gauntlet of other things to consider as well. Emissions testing in your particular area may prevent the practical (or legal) application of a full-scale, hard-wired stand-alone in your vehicle. And again, in the case of emissions testing, the ability to quickly revert back to stock may prove a godsend.
Furthermore, piggyback EMUs can be configured to be nearly transparent when the car isn't in boost, allowing the car to maintain stock-like driveability and functioning of all ECU controlled devices. Piggybacks only make alterations based on the stock map, and while they aren't plug-and-play, in a low-boost application in which conservative fuel and spark maps are used, the e-manage Ultimate may be the best bang for the buck. It's all about proper planning and picking a combination of parts that are best suited for your application.
Now that GReddy has helped narrow the gap between the "haves" and the "have-nots" by offering full fuel and spark mapping even a Wal-Mart employee can afford, are we any closer to that "ownership society"? We don't know, but join us next month as we install the e-manage Ultimate into our super-duper twin-charged M60/T61-hybrid Pinto wagon. 'Betcha didn't know they made OBD-II compliant Pintos, did you? Okay, actually it's an Integra GSR, but no less exciting.
FunctionsAirflow Correction Airflow Adjustment Map / Airflow Output Map / BoostLimiter Cut Map / Anti-Engine Stall Map
Injector CorrectionInjector Adjustment Map x2 / Acceleration Injection Adjustment Map / Individual Cylinder Injection Adjustment / A/F Target Value Map / Vehicle Speed Correction Map, Coolant Temp Correction Map, Intake Air Temp Correction Map / Rev Limiter Cut
Ignition AdjustmentIgnition Correction Map x2 / Acceleration Ignition Map / Individual Cylinder Ignition ADJ Maps / Ignition Cut Feature / A/T Shift Compensation Feature
OthersExternal Output Map (VTEC) / NVCS Control Map / AnalogOutput Map / Idle Stabilization Map
Additional Functions Serial PortExternal Data (such as GReddy Warning Meters and other future optional products) can be monitored and recorded in real time through a data link cable.
Switch PortData Logging and Ignition Cut features can be activated with the use of an optional Remote Switching System and Switching Harness
Option 1/2GReddy Pressure Sensor, GReddy Temp Sensor, A/F Input Harness, Multi Switching System Adaptor, External Switch and Factory Pressure Sensor