In lower than a technology–so, in little greater than a few many years–the picture of an engine tuning skilled has shifted utterly. It was once a man in greasy overalls armed with a set of vacuum gauges and an incredible ear. Now it’s somebody–possibly not even in the identical room or state because the machine they’re tuning–hovering over a laptop computer that’s linked to a automotive’s onboard engine management pc.
With the proliferation of computer-controlled powerplants, tuning is not carried out with a wrench and screwdriver, however with the adjustment of parameters managed by the ECU.
However because the know-how progressed, our need to change our engines with upgraded arduous elements didn’t wane. Early pc engine controls–basically glorified hardwired logic circuits with restricted processing energy–had some flexibility to regulate engine parameters to compensate for upgraded arduous elements. Nevertheless, many wanted extra “piggyback” controllers wired into the circuit. A piggyback would alter the sign it acquired from a sensor earlier than passing it alongside to the inventory pc. It may additionally work in reverse, altering the sign from the inventory pc earlier than sending it to the sensors.
Subsequent generations of manufacturing facility engine controls added processing energy and the power to work together with the engine in actual time. The place early pc controls have been based mostly closely on tables predefined by manufacturing facility engineers, later OEM ECUs may monitor engine information–like consumption and exhaust temperature, engine temperature, throttle place and extra–to make choices on the fly. How a lot gasoline and spark? When to fireside that spark? The solutions have been based mostly on how greatest to serve the motive force’s needs.
All by the event of ECUs outfitted by factories, a struggle with the aftermarket raged. When a producer launched a brand new automotive, it challenged the aftermarket to “crack” the ECU–to reprogram it to function outdoors its typical envelope–permitting the usage of aftermarket arduous elements.
And for some time, this method labored for fans. Many well-liked automobiles had, and proceed to be outfitted with, ECUs that may be “reflashed” or reprogrammed. For lots of parents–those that merely need to add a efficiency exhaust, optimize their tune for high-octane gasoline, or add a little bit of enhance to a turbocharged automotive–flash tunes in manufacturing facility ECUs stay a strong selection.
However what if a construct is extra complicated or extra singularly devoted? What if the proprietor merely needs extra direct management over the 1s and 0s controlling their engine? That’s the place aftermarket ECUs come in.
Lately, builders have quite a few choices for standalone engine administration, and so they’re simpler than ever to put in, tune and afford. From open-source software program working on simply discovered {hardware} to military-grade options designed to endure the pains of motorsport, the alternatives are limitless. We’re right here to assist information you on that journey.
Why Do You Want an Aftermarket ECU?
Bought an engine in your automotive that it didn’t include initially? Aftermarket ECU to the rescue.
Want to manage or compensate for energy adders that your automotive by no means got here with, like turbos or superchargers or hog-ass cams? Hey, standalone.
Need deeper and extra granular adjustability than reflashing your manufacturing facility ECU offers you? An aftermarket ECU is in your future.
Does your automotive’s inventory pc have very restricted adjustability? (We’re taking a look at you, Honda and Acura and early Mazda Miatas.) Guess what? There’s an ECU for that.
“You recognize it’s time to think about upgrading your race automotive to a standalone ECU when what’s controlling your engine and energy adders is not efficient,” explains Lawson Mollica at AEM Efficiency Electronics, a longtime provider of standalone methods.
He sees three typical eventualities that spur the leap to a standalone ECU. The primary on his checklist: “The ’alphabet soup’ strategy, the place varied controllers are added to a car because it’s upgraded–air-fuel controller, enhance controller, ignition controller, flashed ECU, and many others.–and the person is left with a number of electronics that each one should be programmed independently of each other and don’t converse with one another.” The frequent end result, he notes, is main engine failure.
Two essential items of the standalone recipe: a laptop computer and somebody to make use of it. Images Credit score: Kevin Adolf
The following scenario: “When a reflash or open-source tuning technique exceeds the power to manage the ability degree of an engine.”
The final situation is the outlier, he says, however can yield the best returns: “When somebody has a longterm plan and invests in a standalone from the outset, they are going to by no means need to improve their electronics as they make upgrades to their car. This uncommon breed of racer has the power to study the system whereas the car remains to be being developed, making every improve simpler to tune for.”
Why Don’t You Want an Aftermarket ECU?
As a result of they appear overwhelming? Okay, except for that, there are legit causes to not combine some fashionable electronics into your construct.
For one, many more recent automobiles have closely built-in pc methods. A central pc offers not solely ECU capabilities, however physique management module capabilities as properly. Having extra energy is cool, however not in case your air conditioner not works or your manufacturing facility alarm is at all times going off.
And a few fashionable automobiles combine chassis administration capabilities–like stability and traction management methods–into their ECUs. This could complicate facilitation of a standalone ECU.
Ed Senf has been tuning race automobiles for many years–GRM first labored with him 20-plus years in the past. For extra concerned initiatives–like BimmerWorld’s Bergsteiger BMW–Ed stresses the significance of the longterm relationship. Images Credit score: Kevin Adlf
“Proudly owning a automotive outfitted with a standalone ECU is a bit like having a toddler: There’s a accountability dynamic that most individuals aren’t initially conscious of,” explains Shane Benson of AIM Tuning, a agency that focuses on distant tuning of the NA- and NB-chassis Miata.
“OEMs spend 1000’s of hours and hundreds of thousands of {dollars} creating calibrations that may run on each model of that automotive in each conceivable situation. With a standalone ECU, it’s simply us engaged on one particular automotive, in all probability when now we have a number of additional hours to fiddle with it.”
Shane additionally notes that, with a standalone, you don’t have the benefit of beginning with a manufacturing facility tune. “Due to this,” he explains, “nailing down all of the little particulars that make on a regular basis drivability a pleasure could be a a lot larger problem. Issues like cranking and chilly begins, after-start enrichments and warmup can take time as a result of we actually solely get one or two pictures at most per day. Closed-loop idle, acceleration enrichments, electrical hundreds, heat-soaked beginning, EGO compensations, a/c idle up, and many others., all should be calibrated for our personal particular car.”
Lengthy story brief, seek the advice of the producer of your proposed ECU earlier than you begin slicing wires. Chances are high its engineers have expertise along with your supposed software and may information you towards the proper reply.
How A lot ECU Do You Want?
Right here’s the place issues get difficult. The choices are quite a few and broad, and whilst you need to future-proof your construct to some extent, there could also be options in some high-end methods that you simply’ll merely by no means want.
So when ECU buying, listed here are a number of questions to think about about your software:
Can you employ any of your current sensors and wiring harness? Many firms supply plug-and-play choices that leverage current computer-controlled infrastructure and easily substitute your pc with a extra programmable one. Or will you want to run a devoted harness and account for particular sensors that the pc wants to observe?
What kind of atmosphere will your automotive be utilized in? As you climb the ladder from consumer-friendly methods to extra motorsport-based options, one of the seen enhancements is the ruggedness of the particular tools.
Motorsport-grade ECUs stay in weather- and shock-proof instances and are related to the harness through military-style sealed connectors; the worth will replicate that. Many high-end or motorsport ECUs additionally function the power to retailer a number of tuning maps that may be switched on the fly with no need a reboot of the pc.
Wish to add or scale back energy on the flick of a change, or change the way in which your engine delivers that energy–say, for an surprising, traction-reducing bathe throughout a observe session? No drawback, supplied you’re keen to purchase the gear and correctly program it.
What number of issues are you attempting to manage and monitor? At its most simple, an engine management pc is controlling gasoline movement into the cylinders in addition to the spark lighting that flamable combination. However the variety of inputs it considers when deciding the best way to regulate these gasoline and spark settings can scale wildly.
From the essential capabilities it must carry out essentially the most rudimentary elements of its job—like monitoring crank place, consumption temperature and throttle place–to extra superior suggestions loops, an ECU can monitor practically something.
A giant query when contemplating a stand-alone system: Use the OE harness or wire the automotive from scratch? Images Credit score: Chris Tropea
Are you able to tune every cylinder individually? Positive, however you’ll want the correct {hardware} to observe the parameters of that cylinder.
“The wants of every cylinder are distinctive as a consequence of a number of variables, however mostly as a consequence of airflow and/or injector variances,” explains Jerry Hoffmann, founding father of DIYAutoTune.com.
“If you happen to tune your turbo engine out to what you suppose to be a protected air-fuel ratio of 11:1 on gasoline, however you’re solely trying on the common, that might imply one cylinder is working overly wealthy at 9.5:1 and washing down the cylinders whereas additionally down a bit on energy and one other cylinder is at 12.5:1, able to soften down. In that situation, you not solely left numerous energy on the desk, however you had the power to make that energy safely with a correct management system. But you selected to not.”
Are you able to restrict enhance based mostly on which gear the transmission is in? In fact you may, however the pc might want to know which gear the transmission is in.
Traction management? That, too, however you’ll want a method to feed wheel velocity information to the ECU so it is aware of when to chop energy.
All of those superior eventualities are attainable with available {hardware}, however they require the correct sensor packaging and educated programming to facilitate their use.
Wait, I Need to Program It?
Effectively, yeah, and that’s the ultimate little bit of complication. Integrating an aftermarket ECU into your construct could also be bodily easy, however getting it to run might be a harder proposition.
The excellent news: Making energy might be one of many best capabilities to study for somebody with little tuning expertise. Discover the best air-fuel ratio on your chosen gasoline kind and go from there.
However max energy at full throttle is just a part of the equation. “What number of instances have you ever heard the story in regards to the man who took his standalone-equipped automotive to the dyno and got here again with a tune that made nice numbers however began and drove like crap in any scenario aside from wide-open throttle?” asks Shane Benson of AIM Tuning.
Interfaces and value matter, too, because the system will should be programmed. Earlier than making a purchase order, be sure that the system’s interface is a match on your ability set. Images Credit: J.G. Pasterjak
“It’s no enjoyable combating a automotive that doesn’t drive easily below all situations,” he continues. “Studying and trial and error are a part of the method, however it’s properly well worth the effort. It’s arduous to beat the satisfaction supplied when the tune–your tune–purrs like a kitten merely cruising round city, and plasters an enormous ol’ grin throughout your face as you nail the throttle and are rewarded with on the spot efficiency gratification.”
Tuning a automotive for a broad torque band, drivability in quite a lot of situations, chilly begins and extra takes a bit extra finesse on the laptop computer. OEMs have a few years and plenty of hundreds of thousands of {dollars} to dedicate to those particular eventualities. You tuning a automotive in your storage has possibly two pictures a day at getting a cold-start tune labored out.
Additionally keep in mind that the purpose of an aftermarket ECU is to provide the tuner full management over engine perform parameters–and that management should be exercised judiciously. Simply as you may simply microwave a burrito so scorching that it explodes, you may trigger harm with improper ECU programming.
Professional Recommendation: Search It
Finally, we don’t need to scare you off from taking the plunge on an aftermarket ECU. Happily, there’s a complete data base on the market ready to assist.
And actually, consulting these consultants and the neighborhood knowledge for these merchandise could also be the very best place to begin. When putting in a preferred ECU in a preferred automotive, you may usually discover a base or “startup” tune on-line from a trusted supply–generally even the ECU producer itself. And with fashionable web connectivity, not even geography prevents an skilled from immediately tuning your automotive.
Images Credit score: Chris Tropea
Finally, our greatest recommendation is, except you’re an skilled at these purposes, don’t attempt to reinvent the wheel. Your first expertise with an aftermarket ECU shouldn’t be the primary time anybody has ever put in the system you need to set up on the appliance you plan to put in it on. Lean on the present data base as a lot as potential and get some strategies from this gear information. Comfortable tuning.
Case Examine: Swapping our Corvette to a Standalone ECU
After deciding to LS-swap our already LS-powered Corvette, we had to determine the best way to management our new engine. “However you LS-swapped a automotive that already had an LS engine,” you say, “which isn’t even technically a swap.”
Bringing Our LS3-Powered C5 Corvette to Life | Project C5 Corvette Z06
Sure, we hear you. Swapping one LS for an additional may appear seamless from a bodily fitment perspective, however varied generations of LS engines have some key variations that complicate the matter. For instance, our authentic LS6 powerplant, which is taken into account the Gen III evolution of the Small-Block Chevy engine, got here fitted with a 24-tooth reluctor wheel hooked up to the crank. This reluctor wheel sends positional information to the ECU for timing functions.
Our alternative engine, the Gen IV LS3, makes use of a 58-tooth wheel. The LS3 additionally has some repositioned sensors and connectors. Plus, it makes use of a drive-by-wire throttle physique that hinges in the wrong way.
Now, you completely can run a extra fashionable LS3 off the manufacturing facility C5 Corvette Z06 ECU if you wish to. Lingenfelter Efficiency makes a magic field that converts the reluctor wheel sign to a usable format, and adapters and extensions can be found to get the inventory harness to interface correctly. The throttle physique difficulty could be overcome by utilizing one from an LS2-powered GTO, though these have gotten more and more more durable to seek out.
If we have been constructing this automotive for every day driver use, retaining the manufacturing facility ECU is likely to be a strong possibility. We’d find yourself with no conflicts between the engine management and physique management capabilities of the manufacturing facility ECU, and we’d have a totally practical manufacturing facility gauge cluster nonetheless in place.
Whereas upgrading our Corvette to LS3 energy, we additionally moved to a totally programmable ECU from Holley. We began with the Terminator X Max earlier than switching to the extra weatherproof Dominator. Each use the identical harness connections.
However we’d additionally have to stay by the restrictions of the manufacturing facility ECU relating to efficiency and tuning. Sure, the manufacturing facility ECU tune could be overwritten, however the course of can contain a clunky interface. Rewrites also can take some time to add to the ECU and restrict choices relating to energy adders, too.
Since our Corvette is a observe automotive, shifting to a devoted ECU was a straightforward resolution. We ordered up a Holley Terminator X Max ECU, which mixes a budget-friendly value–lower than $1400–with plug-and-play simplicity due to Holley’s LS3-specific wiring harness.
The ECU additionally includes a 3.5-inch handheld touchscreen that permits direct entry to many frequent tuning capabilities with out the necessity to join a laptop computer. The Holley harness doesn’t interface with the older C5 throttle, nonetheless, so we had so as to add a drive-by-wire throttle pedal from a late-model GM SUV. That was the one difficult half.
The harness was really plug-and-play, with the Holley changing the inventory ECU–which we left in place to manage some physique capabilities like lighting, energy home windows, central locking, the gasoline gauge and some different equipment. The 2 harnesses merge on the radiator followers, nonetheless; the inventory ECU controls the followers, however the Holley must know after they’re working.
Getting the Corvette working on the Holley ECU wasn’t a lot of a problem. It comes programmed with startup maps for a lot of frequent engine selections, though we used a map already developed by Redline Tuning Companies, our tuner on this venture. The engine fired after just a few cranks, with solely minimal modifications wanted as soon as on the dyno.
The draw back of an aftermarket ECU like our Holley Terminator is the lack of functioning gauges; these obtain information from the inventory ECU, which, in our case, was not listening to the engine.
This draw back has an upside, nonetheless: We may now join the Holley ECU to one of many firm’s show models for full and straightforward monitoring. We used the 6.86-inch Professional Sprint, which runs just a little greater than a thousand {dollars}. It completely match within the heart console, proper within the area vacated by our stereo. Only a slight modification was wanted to the single-DIN bezel that had been wrapped round our aftermarket head unit. The end result: a Holley Sprint that appears nearly manufacturing facility and suits very cleanly.
And that sprint is greater than merely a touch. The interface is totally customizable, proper from the touch-sensitive sprint panel itself. This allowed us to arrange {custom} gauge configurations, which got here in useful throughout the break-in of our new engine. Now we are able to have separate gauge setups for autocross, observe time and testing, every based mostly on the parameters we most need to monitor at that second.
We ultimately upgraded to Holley’s Dominator ECU–relying on choices, about $2400. This one options much more inputs and capabilities, and it’s severely weatherproof–an enormous plus for us since we mounted the ECU contained in the driver-side fender. The totally sealed and potted Dominator has moisture-proof connectors, and we additionally sealed off the unused connectors with clean plugs stuffed with blanking pins and silicone.
We mounted our Dominator ECU behind the driver-side fender, so we plugged the unused ports with silicone-filled blanks for added weatherproofing. Our show options simply the essential readouts–like custom-made out-of-range warning lights–plus a change for the cooling followers. We discovered Holley’s ECU menus intuitive and straightforward to tweak.
In use, each Holley ECUs actually opened up our choices for altering engine parameters whereas additionally dramatically slicing down on the time wanted to take action. ECU rewrites happen in seconds, and the interface is without doubt one of the extra intuitive ones we’ve used.
We additionally love the number of conditional set off choices constructed proper into most of the management capabilities. Along with simply constructing {custom} gauges, we are able to add {custom} switches to manage varied capabilities.
For instance, we wished so as to add a handbook fan override change to the Holley Professional Sprint. We have been capable of inform the Holley ECU when to show the followers on and off utilizing easy, predefined conditional phrases like “or,” “if,” and “and,” together with a number of different frequent situation definitions. This allowed us to string collectively a set off system that activates the followers as soon as the coolant temperature reaches a sure vary.
We may additionally program a digital change on the show itself to function the followers provided that the engine is working or if engine temps cross a sure threshold. These instructions have been all obtainable by well-designed dropdown menus.
Certainly one of our favourite capabilities of the Holley ECU, although, includes the throttle response curves. Truthfully, it’s among the finest arguments for shifting to a drive-by-wire setup. How pedal place corresponds to throttle opening is a key factor of driver interface, and whereas that perform received’t achieve us any extra energy, it is going to completely have an effect on the way in which the automotive is pushed.
We now have particular throttle curves for each autocross and observe use; the autocross curve is a bit much less aggressive, since an excessive amount of throttle too quickly in a decrease gear may severely upset chassis stability with all that torque on faucet. Switching backwards and forwards–and even custom-tweaking the setting for both–takes just some seconds.
Did the aftermarket ECU assist us make extra energy? That’s arduous to reply, since a base tune for our setup doesn’t actually exist. Nevertheless, our present dyno sheets again up those that got here from our engine builder.
So, the massive benefit of a standalone in our scenario? Being able to entry each engine perform simply and rapidly with just some keystrokes. We are able to now make tuning and setup modifications between classes and even between autocross runs, all with out ever leaving the motive force’s seat.
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