Well folks, my Powercommander V arrives in the mail today and my Autotune arrives in a few days. I was baffled for a while regarding exactly how the Autotune module works. It seems the questions that come to mind for most folks are:
So here are the definitive answers to both those questions, but the second one is the important question!
What is the autotune actually doing?
So the autotune is basically a wideband O2 (oxygen) sensor. "Wideband" means it can detect almost-instant changes in the Air-Fuel ratio, and the reason you care about this is because the Power commander is fundamentally a device which changes your air/fuel mixture to get better and smoother power delivery. But this doesn't really answer what the Autotune does...
Now in the case of the Autotune and PCV, it's a wideband O2 sensor which is comparing the air/fuel ratio of your exhaust gases and matching them to the RPM you are doing, the position of your throttle, and what gear you are in. But this STILL doesn't answer what the autotune does!
So, what the autotune is doing is this: It is monitoring your O2 levels in the exhaust and altering your fuel mixture to match a DEFINED AIR/FUEL RATIO SET BY YOU IN THE POWERCOMMANDER.
Read that carefully: It is adjusting your fuel mixture to meet an air/fuel ratio which YOU define first. So this means you can't just plug it in with no map in the Powercommander and expect it do anything valuable! And so we lead into our next question:
Do I need a custom map at all?
Kinda. When you have an Autotune what you're REALLY looking for is the perfect air/fuel ratio (let's call it "AFR") set for each rpm and throttle position. This AFR should be a value which provides the most power *for your bike*. Whoa - wait a second! Let's have a look what a dyno tuning centre does:
Really, the only way to find the perfect AFR for your bike is....to put it on a dyno and get a custom tune! Having an Autotune module means that once you ride away, your Power commander is permanently, always, constantly making "trim" adjustments to the map the dyno tuner installed to keep hitting that target AFR. These minute adjustments help ensure that your AFR sticks to the desired target forever - even as your engine wears, you ride into different altitudes, the humidity changes, or the air temperature changes.
Did you know that literally every car on the road has an Autotune built in? It's the O2 sensor in the exhaust, but they are usually narrowband O2 sensors and react very slowly to changes in AFR. By installing an autotune on your bike and having accurate target AFR values defined in your power commander, you haved just made your VFR a "closed loop" ECU with near-instantaneous retuning capability to maintain that AFR. Heck, if you wanted to, you could use your PCV and Autotune to make your bike better for the environment by maintaining an AFR which was perfect for the catalytic converter. It may perform like a bucket of bolts, but you might meet Euro IV emissions requirements!
But to make it work, you need to start with the right target Air/Fuel Ratio. It's the core of what makes the Autotune work, because the Autotune doesn't known what AFR makes the most power on your bike or which is the smoothest. All it knows what to do is measure the AFR and try to adjust the Power commander map to meet the AFR you tell it to get to.
But what if I don't want a custom map!
OK, OK, I hear you. If you don't want perfection, you can just do the following:
If you choose a zero map, it will take longer for the Autotune to "get it right" as it may hit your maximum trim limit and you will have to accept the trims and roll them into your base map, then allow it to make more trims on another ride, in order to let it get where it needs to go to reach the AFR of 13.2.
If you take a close look at Coderighter's target Air/Fuel rations for 6th-gear on his '06 VFR you will notice they differ a lot depending on engine rpms and throttle position. In particular, look at his "just off-idle" values down around 1,250rpm and less than 10% throttle.
http://www.vfrdiscussion.com/forum/uploads/1268557440/gallery_380_5242_133248.jpg
Coderighter's AFR targets for 6th gear
This is what you want to get to on your bike - the best AFR value for each RPM and throttle position, and possibly also the gear you're in (if you want to go that far).
- What is the autotune actually doing?
- Do I need a custom map at all?
So here are the definitive answers to both those questions, but the second one is the important question!
What is the autotune actually doing?
So the autotune is basically a wideband O2 (oxygen) sensor. "Wideband" means it can detect almost-instant changes in the Air-Fuel ratio, and the reason you care about this is because the Power commander is fundamentally a device which changes your air/fuel mixture to get better and smoother power delivery. But this doesn't really answer what the Autotune does...
Now in the case of the Autotune and PCV, it's a wideband O2 sensor which is comparing the air/fuel ratio of your exhaust gases and matching them to the RPM you are doing, the position of your throttle, and what gear you are in. But this STILL doesn't answer what the autotune does!
So, what the autotune is doing is this: It is monitoring your O2 levels in the exhaust and altering your fuel mixture to match a DEFINED AIR/FUEL RATIO SET BY YOU IN THE POWERCOMMANDER.
Read that carefully: It is adjusting your fuel mixture to meet an air/fuel ratio which YOU define first. So this means you can't just plug it in with no map in the Powercommander and expect it do anything valuable! And so we lead into our next question:
Do I need a custom map at all?
Kinda. When you have an Autotune what you're REALLY looking for is the perfect air/fuel ratio (let's call it "AFR") set for each rpm and throttle position. This AFR should be a value which provides the most power *for your bike*. Whoa - wait a second! Let's have a look what a dyno tuning centre does:
- Stick the bike on the dyno
- Find the AFR which makes the most power on your bike for all RPM and throttle positions
- Program the Powercommander to get as close as possible to these AFR values
Really, the only way to find the perfect AFR for your bike is....to put it on a dyno and get a custom tune! Having an Autotune module means that once you ride away, your Power commander is permanently, always, constantly making "trim" adjustments to the map the dyno tuner installed to keep hitting that target AFR. These minute adjustments help ensure that your AFR sticks to the desired target forever - even as your engine wears, you ride into different altitudes, the humidity changes, or the air temperature changes.
Did you know that literally every car on the road has an Autotune built in? It's the O2 sensor in the exhaust, but they are usually narrowband O2 sensors and react very slowly to changes in AFR. By installing an autotune on your bike and having accurate target AFR values defined in your power commander, you haved just made your VFR a "closed loop" ECU with near-instantaneous retuning capability to maintain that AFR. Heck, if you wanted to, you could use your PCV and Autotune to make your bike better for the environment by maintaining an AFR which was perfect for the catalytic converter. It may perform like a bucket of bolts, but you might meet Euro IV emissions requirements!
But to make it work, you need to start with the right target Air/Fuel Ratio. It's the core of what makes the Autotune work, because the Autotune doesn't known what AFR makes the most power on your bike or which is the smoothest. All it knows what to do is measure the AFR and try to adjust the Power commander map to meet the AFR you tell it to get to.
But what if I don't want a custom map!
OK, OK, I hear you. If you don't want perfection, you can just do the following:
- Load either a zero map or one closest to your bike's modifications
- Set the target AFR to 13.2 for most RPMs and throttle positions
- Tweak the AFR value for just off idle to avoid snatchiness
- Tweak the AFR value for the smoothest VTEC transition
If you choose a zero map, it will take longer for the Autotune to "get it right" as it may hit your maximum trim limit and you will have to accept the trims and roll them into your base map, then allow it to make more trims on another ride, in order to let it get where it needs to go to reach the AFR of 13.2.
If you take a close look at Coderighter's target Air/Fuel rations for 6th-gear on his '06 VFR you will notice they differ a lot depending on engine rpms and throttle position. In particular, look at his "just off-idle" values down around 1,250rpm and less than 10% throttle.
http://www.vfrdiscussion.com/forum/uploads/1268557440/gallery_380_5242_133248.jpg
Coderighter's AFR targets for 6th gear
This is what you want to get to on your bike - the best AFR value for each RPM and throttle position, and possibly also the gear you're in (if you want to go that far).