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Introduction to Engine Tuning: Reflashing Explained

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Reflashing Explained


00:00 - We've talked about fitting a standalone engine management system already, but that's not the only way to achieve your tuning changes.
00:08 As cars have become more complex, it's becoming increasingly difficult to completely do away with the factory ECU and fit a standalone system.
00:18 This is because all of the cars electronic systems communicate together, and removing the engine computer from this network can remove messages that are vital to other components in the car.
00:31 At best, you might end up with a car where the air-conditioning no longer works, but in most instances, the results will be much more serious, and you're quite likely to end up with a car where the gearbox won’t change gear, and maybe the instrument cluster doesn't work.
00:47 The end result can quite likely be a car that can't even be driven.
00:52 An alternative option with many of these late model cars is to make tuning changes directly to the stock factory-fitted ECU.
01:02 This forms the basis of the technique of reflashing, and it's an immensely powerful option that can be applied to many cars that were produced after approximately the year 2000.
01:15 Reflashing involves connecting to the factory ECU via the OBD II diagnostics port and downloading the stock map data.
01:25 Once we've done this, we can view and modify the tuning parameters as required, and then flash the new tune back into the ECU.
01:35 In this way, we're actually making tuning changes in the same way as the factory engineers performed the task.
01:42 Since we're retaining the factory ECU, we can still expect all of the car's electronic subsystems to function as they did originally, only now we have control over the tuning.
01:55 Reflashing is a powerful option if it's available for your car, and since we don't need to outlay anything for a new standalone ECU, it can also be very cost effective.
02:09 Another advantage of reflashing is that the factory engineers have already poured a huge amount of time, money, and resources into developing the original ECU with the sole aim of doing the best job possible of controlling your engine.
02:27 This is quite different to the standalone market, where the same ECU might be expected to adequately run thousands of different engine types, and unsurprisingly, this can put you ahead of all but the most sophisticated standalone ECUs when it comes to doing the best job of running your engine.
02:50 There are two types of reflashing products available.
02:54 Commercial reflashing products are ones where you pay for the software and hardware required to tune a vehicle.
03:02 These normally come with great documentation and support, which makes it easy to get specific help if you have questions.
03:10 The other option comes from the open source community where the software is often free.
03:17 Open source reflashing software will offer less support and documentation, though, and requires you to do a little more research if you get stuck or have questions.
03:29 With the amount of work that's been poured into the reflashing market by many of the commercial software manufacturers, as well as some smart people in the open source community, there is now almost no limit to what you can achieve with the factory ECU.
03:46 This is achieved by rewriting some of the factory ECU code to change the way it operates, or add features that never originally existed.
03:57 This, for example, may allow us to add a supercharger or turbocharger to an engine that was originally, naturally aspirated, or perhaps add motorsport functions that were never supported, such as launch control or flat shifting.
04:13 We may also have the ability to alter the way the ECU measures the amount of air entering the engine and perhaps swap from a mass airflow sensor to a system that calculates air flow using a MAF sensor.
04:28 Reflashing relies on a hardware interface that goes between your laptop and the car's diagnostic port as well as some special software that allows you to download data from the ECU.
04:41 The raw data inside the ECU on its own, however, isn't much use to us.
04:47 The reflashing software will include a graphical interface that allows us to view the different MAFs and manipulate them in a way that makes sense to us as tuners.
04:59 With the advances in reflashing hardware and software, combined with custom modification of the factory ECU's code, reflashing is often the best option if you're wanting to make modifications to the tune in your car.
05:16 In fact, it's getting to be a little difficult to draw a clear line as to where and why you would an aftermarket, standalone ECU over reflashing the stock ECU.
05:29 In most instances, where the option to reflash your stock ECU exists, this is going to be the cheapest and most cost-effective way of tuning your car.
05:40 Of course, not all vehicles are supported with reflashing options, and some vehicles have more complete support than others, so some research into what's available for your particular application is essential before making your final decision.
05:58 HPA's online forum is the perfect place to ask these sort of questions and get feedback about your options.

We usually reply within 12hrs (often sooner)

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