TUNING
To start, I think it's a good idea to establish what engine tuning is, and what it can and cannot do. Think of an engine as an air pump. The more efficiently it can pump air, the less losses that are drained through friction, restricted air flow, etc, the more efficient the engine will be. This efficiency will result in better fuel economy AND better power, if done properly.
Engine tuning is basically optimizing the performance of the hard parts selected that make up the engine, including the intake and exhaust components. At it's core, tuning is controlling cylinder pressures and heat at the highest level possible without overloading the octane value of the fuel selected.
Overrunning the fuels ability to resist self ignition (gas knock or it's variants) is devastating to power, economy, and engine longevity. Good engine tuning will capitalize on capturing as much air / fuel mix as possible and turn it into usable energy to move the vehicle.
What tuning CANNOT do is to “create” power. It's not like adding an extra cylinder to the engine, so there is a finite amount of power that can be extracted from the fuel. Once that has been reached, that's it for the given engine / fuel combination.
That's why folks add things like larger exhaust systems, larger throttle bodies, etc... because once the limits of the original combination is reached, it will take a change of the hard parts to be able to get more power from the engine. It must be remembered that engine power is actually measured as torque, and horsepower is a mathematical derivative of that.
I don't want to go to far with that now because it's another subject altogether, but suffice it to say that to make significantly more horsepower from a given displacement naturally aspirated engine will require an increase in peak RPM. With higher RPM comes more momentum of the engines' reciprocating mass, and the closer the engine brushes up against the load limits of the parts and eventual self destruction.
All of this must be considered from a mature tuner's point of view. When is enough enough? To me a good tuner “listens” to what the engine is telling him and gets the gains available without driving the engine into self destruction.
Almost 40 years ago when I first started building and tuning engines, I read a book that I still have, titled “The Design and Tuning of Competition Engines” . In that book a philosophy of tuning was laid out; basically it said that tuning was like climbing a mountain in that you never know when you've reached the summit until you start to go down the other side.
That made a lot of sense to me, and I then adopted that philosophy to my tuning. What that means in action is that I'll continue to “climb the mountain” as I am changing tuning parameters, not knowing what the ultimate “peak tune” will be until I've passed it and start losing power, economy, or whatever I was searching for.
I can then back up to the “peak” and be sure that it really is “the peak”. I understand what the engine is telling me, and follow the path it sends me. This is a very tedious process, but at least it insures no stone was left unturned.
I am a mature tuner. The first thing I want to do is be sure my tune is SAFE, because pushing any tuning parameters to the point of potential engine damage is a foolish thing to do. If I sacrifice a couple HP so be it, it beats turning your engine into an expensive chunk of busted up metal.
I use E10 pump gas because this is representative of common fuels any owner will likely encounter. I also do not feel exhausting the very last high rpm potential is a good idea. Bad things happen when all that reciprocating mass gets whipping around inside the engine at high RPM's.
I'm conservative, pragmatic, and thorough.
FLASHING
For those new to flashing, let me explain. The Shoodaben Engineering ECU flash is changing the tuning parameters of the ECU (engine control unit) . It's easily done by removing the ECU and sending it in to have the parameters re-written. This is called "flashing the ECU". When done properly with professional tuning, there will be no downside to flashing. It will not harm your engine, reduce your fuel economy or impact your warranty. It will, however, improve the performance and make your bike more enjoyable to ride. It's also not necessary to do other modifications to your bike to enjoy these benefits. You won't need to change the exhaust, air filter,, although I have flashes to support those changes. etc. Shoodaben Engineering has flashed ECU's since 2015 with zero failures to ECU or engine, so feel comfortable that this is a well established and reliable modification.