Piggyback vs. ECU Flash

Piggyback vs. ECU Flash... whats the difference?

Well Let us explain:

First we must say that the evolution of engine management systems (which control both fuel and ignition) have made fantastic steps forward over the years. However, ECU systems are different, manufacturer spend different amount on money depending on what type of bike. But overall they have become better and better. At least technicaly.

Back in the late 1980:s for the first time engine management found it’s way to the racingtracks. Weber Marelli IAW on those ”Big Twins” from Bologna. IAW had functions making it very suitable for (racing) motorcycles. At that time you could lift the cover on the ECU and put in a new PROM, it was even possible to have two PROM:s and swap on the fly with a switch. And they had a PROM for each racetrack. Very costly system!

10-15years later the Japanese manufacturer introduced similar systems on their streetbikes. But as always technology moves forward, and the old PROM chips was instead Flash memory - not intended to tamper with! However, those ECU:s came with an electrical backdoor. The Flash need to be programmed in some way at the factory.

Back then very little information was around how to do. And perhaps even less what actually was hidden inside the ECU.

The solution became an extra ECU connected between injectors and main ECU. Piggyback solution. Adjusting fueling in realtime, a bit more here and a bit less there. This was done by reading different parameters from main ECU and then adjust injector ”duty-cycle” to add or reduce the amount of fuel in the specific loadcell. The data about fuel amount is stored in something looking like an excel spreadsheet. If you make a 3D view of it, it looks like a map.

What was good was that the userinterface was easy to access and your local tuner could do their magic. Iron out the fueling for whatever modifications you made to your bike.

If you start to do more extreme modification, like Turbo conversion, you need to figure out what is inside that ECU. Or you buy and expensive aftermarket system intended for easy tuning. The standard engine management system is fully ok even for extreme racing - if it could be unlocked and parameters modified.

And somewhere here the history of SwedenFastBikeZ started. Hacking into the ECU to be able to create a new ”file” to download with corrected parameters. Instead of using a piggyback solution. When you start to change components like fuel injectors you want to go this way!

Once the ECU was hacked into, it was obvious that it was not one fuelmap, it’s a lot of fuelmaps. In extreme cases each cylinder have a map for each gear and drivermode. And very important, suddenly ignition was possible to access.

Something had changed from those red motorcycles conquering the tracks -80/90 - restrictions. And on top of this limits for noise etc.  Manufacturers don't like to have many different version so very often the settings is made for poor petrol, in worst possible driving situations. Optmized for long service intervals and zero warranty issues. On other hand, the more and more capable ECU:s was a brick in the game of higher power and less fuel consumption.

We don't say that fuel-maps are good, but sometimes really strange things is hidden in the ignition maps. And even if you tune the fueling to perfection with piggyback you wont get that crisp response when ignition is way off.

Simply said, going for an ECU flash you have access to so much more information. You can adjust exactly what you want, without affecting other things.

You can have maximum power at top-end, good torque in midband. Focus on fuel consumption on mid-load. And even put in some fun flames during deaccelaration without compromising other areas.
It’s also possible to access the fan, disable exhaust valve (EXUP). Reduce the interaction from lambda control (part to catalytic converter). You might want to change RPM limiter.
Today we can even add functions that was not available when your bike was new. Like implementing a quickshifter or pit-speedlimiter.

Even that the latest piggyback solutions are more capable than before. You have to walk a long want to get to the position where you realize that all of this could have been done better in the ECU directly.

But ECU:s are locked from factory, no information available about their functionality. It require, time, dedication, skills and some money to figure this out. And it’s a lot of ECU:s around, we use over 10different tools to get access. And sometimes we face a new ”lock”, and need to go to the locksmith before we can enter the tables of magic we want access. Even that we have learned over the years, it’s time consuming work.

Fortunately, nowadays we're a team working with the same dedication. Of course how all of this magic is performed is our trade secret.

The good thing with piggyback is that you can easily remove it. Perhaps a wanted solution if you're under warranty, often the main ECU don't recognize the ”add” of this. But sometimes it still leaves traces. With ECU Flash, the original file must be read-back again. The ECU sent to a SwedenFastBikeZ dealer to have this performed. And everything is back to normal as it was before! But it comes with a cost.