AN INTRODUCTION TO THE WORLD OF ECU REFLASHING
We like to think that somewhere in the world there’s a big-wig automaker exec sitting behind a mahogany boardroom table yelling, “They can’t handle the truth!” in response to a lowly engineering tech’s suggestion that buyers should be given full capability of their cars. It’s the truth that they don’t want you to know about and the same truth that aftermarket reflashers have been trying to tell us about for years: there’s power to be had out of the box, if you know how to find it.
Yep, these days, most of the power scales offered from manufacture are capped by software that manufacturers try to lock away from you, unless you want to pony up your hard-earned dosh.
The reasons why they do this vary from factory to factory. Some are safeguards designed to cover the use of shitty fuel or to protect the motor from the damage caused when people fail to service their car. Others’ software restricts power to get the car to conform to the different emissions standards for various markets. Whatever the reason it’s done, almost all stock ECU settings are holding back your car’s performance and, in some cases, compromising good fuel economy.
To get you the lowdown on how to unlock this hidden power, how it all works, and what can be achieved on a factory ECU instead of an aftermarket unit, we hit a few industry experts with all our burning questions — and here’s what they had to say.
In basic terms, what is ECU 'reflashing' and how does it work?
Sam Bakalich from CTB Performance says: “The factory engine control unit, or ECU, is also referred to as the car’s ‘computer’, and reflashing is the process of achieving optimum performance from a vehicle by making changes to it.
“What you do, and the results, will depend on what vehicle is being reflashed, but the idea is to tweak different parameters within the ECU to increase power, improve throttle response, torque, fuel economy, etc. If the vehicle is suited to it, we use a pass-through device that is plugged into a vehicle’s on-board diagnostics (OBD) port, which reads the powertrain control module in order to obtain the car’s strategy — each car has a different strategy from factory that consists of parameters suited to its intended use; for example, according to the fuels and atmospheric pressures expected in its intended market. A car suited to Australia’s 50-degree temperatures won’t be optimized for a colder New Zealand climate and so forth.
“Our system sucks that information out, and we can tweak numbers to get the car to operate how we please. The changeable parameters alter depending on the car and what software it runs. Some applications allow us to change things right down to the fans, when they spin and how fast. But we can almost always change the basics of fuel, timing, pressures, boost, and the like. With most vehicles, we have developed a plan before the customer has arrived, as we know it works. Take a 5.0-litre Falcon with a Miami motor, for example. The first thing we do is to tell the wastegate to always stay shut, as the pulley is always going to cap boost at 10psi. Likewise, the factory only enables 60 per cent throttle, which is used as a way to alter power levels out of the factory, so we up that to 100 per cent. From there, we can adjust fuelling and timing to suit.”
How does that affect fuel economy?
Sam tells us: “What I’ve always found is that a power tune and fueleconomy tune tend to be the same thing at their core. A number of American companies will offer a separate tune for each; however, when they’re broken down, the only difference is that they have restricted the accelerator. When tuned to peak power, the motor will run at its optimal fuel efficiency. We always tune a vehicle to its optimum, and nice fuelling should equate to a nice fuel economy — at the end of the day, your real fuel-economy device is your right foot.”
Does reflashing void a new-car warranty?
“In most instances, yes, it will,” explains Sam. “However, only for the engine and transmission. As long as the vehicle is still under new-car warranty, we offer a full driveline warranty with our reflashes. That also means if your electric seats or window wipers fail, your newcar warranty will cover that fault — it doesn’t void the entirety of the car’s warranty.”
Can all factory ECUs be reflashed, or are there some that simply can't be accessed?
Peter James from Superchips says: “The short answer is no, not all ECUs can be accessed. The reason is that many types of ECUs have been used over the years. In some makes, you may find a variety of different types, and manufacturers don’t all use the same ECUs. Each uses certain protocols for the code which is used to communicate with them, and unless you have the factory codes, they cannot be accessed. For example, the newest BMWs use ECUs that haven’t been cracked yet by aftermarket flashers — however, we’re working to generate access to these in the near future. Likewise, some of the older stuff is a bit harder now. Take most cars pre 1996 that have a physical chip. You can still switch these out — that’s where the terms ‘chipping’ or ‘chipped’ come from — but finding the right chip is quite hard these days.
“In saying all that, a huge range of makes and models can be accessed, especially when you’re talking European cars.”
So, which are the common makes/models that can be accessed and will benefit from this sort of treatment the most?
“You can break this down quite simply: turbo diesels will always benefit the most, they’ll see a 35- or 40-per-cent increase in power while actually improving the fuel economy,” says Peter. “Likewise, turbo petrol applications can expect up to a 25-per-cent increase. Non-turbo cars on paper generate around a 10-per-cent increase, but what they lack in outright power gain, they make up for in terms of quicker throttle response and improved fuel economy. BMWs, for example, see a lot better throttle response, and you can remove that horrible flat spot that they have become known for, while, for a Golf R32, you can boost acceleration and low-to-mid range torque, creating a much more lively driving experience.
“There’s a reason you can easily find this kind of improvement. Every year, buyers expect the same, or more, power from any given model, while manufacturers battle to meet European emissions standards. The result is often restricted engines that are high-strung to meet both expectations; however, it’s basic physics that you simply can’t keep pushing both ends to breaking point: eventually, one has to give for the other to increase; there’s no such thing as a free lunch. Reflashing allows a compromise between what can be done and can’t, and we focus on providing a good safe tune, one that lets you feel a noticeable difference, without going beyond the point of reason just for the sake of good figures on paper.”
Does the car have to be put on a dyno to be reflashed?
David Wallace from Tune Technic explains: “Technically speaking, no, the car does not have to be put on the dyno to be reflashed. A vehicle’s ECU can be reflashed without the use of a dyno, as a dyno is simply a tool to measure an engine’s performance whilst monitoring specific engine data. So it’s not mandatory to use one when reflashing, but, in saying that, using a dyno for reflashing gives you the ultimate ability to test and measure throughout. Questions like, has the reflash done what you were expecting; does it need more adjustments; can the tune be further improved; and, is it safe? are all really hard to answer without the use of a dyno and data-logging equipment. If we are reflashing a new engine type that we haven’t worked with previously, it would be impossible to tune it perfectly without the use of a dyno.”
What are the pitfalls of someone trying to do it at home?
Says David, “There is so much that can go wrong when you start changing things without having a full understanding of what you’re doing and what effect it can have on the engine. Reflashing gear has become cheaper and easier to obtain, meaning [that] it may look attractive to have a go at it yourself. Even using a tuning file [that] you found on the internet isn’t a smart move. Without some solid tuning knowledge and the right gear to test what you’ve done, you could destroy the engine or brick the ECU. We sometimes see cars coming in for reflash tuning and it’s obvious that someone’s had a go at it themselves, or downloaded a file from overseas that doesn’t suit their engine. Over the years, ECU architecture has become so much more complex. In the 1990s, ECUs were fairly simple to reverse-engineer and tune. Today’s ECUs have 10 to 20 times the amount of programming code in the firmware. Don’t expect to jump into the code or a tuning programme and raise a few numbers here and there to find some power — it’s just not that simple. If you’re not that easily deterred, then at least get your tune checked by a pro.”
What supporting mods can be used to benefit most from a reflash?
Stewart Mearns from ST Hi-tec tells us: “When it comes to reflashing, you can upgrade anything affecting the airflow in and out of the engine. This generally encompasses air filters, intake piping, larger MAF housings, intercoolers and piping, wastegate actuators and boost solenoids, turbo, downpipes, high-flow or cat deletes, and larger diameter exhausts. Likewise, upgrading fuel systems and making sure the fuel pump is getting full voltage, fuel filters, fuel pressures, right up to larger capacity injectors and fuel rails. This does vary between different makes and models, however, and we are now able to offer ECU reflashing on Nissan, Mazda, Mitsubishi, Subaru, Toyota, Ford, and GM vehicles.”
How untapped is a factory R35 GT-R ECU?
“The factory R35 GT-R ECU is state of the art,” says Stewart. “There are many advantages to reflashing it to a certain power level, the first being retention of all the driveability of a stock car with ability to tune for more power. This is important if vehicles are still under warranty, as the manufacturer’s diagnostic tools can access codes and check vehicle systems. The second advantage is that the factory CAN-bus systems retain communications to all of the vehicle systems, which is key. With EcuTek software, we can unleash the vehicle’s full potential and add many additional features — such as launch control, rolling launch, pop and bang, up to four different tune modes changeable at the touch of the cruise-control switch, variable closed-loop boost control — and even hijack factory gauges for additional displays such as turning the watertemp gauge into a boost gauge or ethanol-content display. We are able to tailor power increases to suit supporting modifications in excess of 100kW more than factory and beyond.”
Have technology advances made it easier to do?
“Yes and no. Tuning each vehicle is the same principle, but now we are able to factor in ultra-close fuel trims, closed-loop fuelling, closed-loop knock, individual cylinder ignition timing, and torque control to keep the transmission reliable, then add in variable camshaft control,” Stewart says. “This is an area where huge gains can be made. While technology has added more dimensions to tuning, it has also enabled serious gains in performance, where we are not limited by emission-control restraints. Rather than ‘dump’ in a basic ROM reflash, we use the latest ROM files as a base tune, then tune each vehicle to optimize performance.”
From the factory, how close to their most efficient do cars run?
Says Carl Ruiterman from E&H Motors, “From factory, most cars are very close to ideal when it comes to fuel mixtures, ignition, and cam timing under light cruise loads. Under full throttle, however, the fuel mixtures are generally way too rich and the ignition timing far from ideal. You can increase the power on a factory tuned turbocharged car by 20 per cent without increasing boost, just by optimizing fuel and ignition timing. By further optimizing cam timing and boost pressure, we can make more power at a lower rpm than the factory did, while reducing turbo lag and holding onto that extra power higher in the rev range. You may think that because the engine is making more power than factory, it is not as safe, but, in most cases, after your factory ECU has been dyno tuned correctly, it is much safer than factory, it will use less fuel under high load, there’ll be less oil contamination, and lower risk of engine knock.
“As factory Japanese turbo cars tend to be set up with very safe, low base ignition timing, they often use knock control to add ignition timing until knock is detected, then add and remove timing to keep it close to ideal. The issue here is that when cruising down the road at lower throttle openings, the ECU adds a lot of timing as it does not detect any knock. When you stand on the throttle quickly, the engine will detonate, and the computer has to pull all the timing out again. Every time the engine knocks, it is potentially damaging and/or weakening the engine. To fix this, we tune the ECU so [that] the ignition timing is optimized for the fuel type and modifications to your engine, so it cannot put in enough timing to get to this knock condition, yet can still add and remove ignition timing for different fuel types or other conditions that have changed to keep your engine safe.”
How far can you push the factory ECU before an aftermarket ECU is required?
Carl explains, “The factory ECU on modern cars — vehicles with OBD-II, such as the Mitsubishi Evo from 1996 and newer, Subaru V7 and newer, Mazda3 and 6, etc. — is very powerful, and can go a long way before it needs to be replaced. They give very good fuel, ignition, knock, cam, and boost control, and will allow us to increase injector size, turbo, intercoolers, and exhaust in most cases. In some cases, they allow some motorsport functions, like launch control.
“One of the limiting factors is the airflow meter, and once you have an engine set-up that is outflowing what the airflow meter can measure, it may be worth looking at aftermarket ECU options. We can increase airflow meter size, or even change to speed density on some computers, but this is usually the crossover point, and it generally happens when you start making over 280kW on a four-cylinder turbocharged engine. Aftermarket ECUs open up the options, such as flex fuel for fuel blends using ethanol, oil-pressure input to protect the engine under oil surge conditions — or no oil at all if something damages your oil-cooler lines or sump — adjustable launch and boost control, anti-lag, etc., although some factory computers are capable of these, so check before buying. For most motorsport cars, we still recommend aftermarket ECU options.”