It's a "manual" autotune setup. The AFRs get set to 14.6 in way more of the table cells than you'd ever want to run with, and you be smart about making the datalogs. The software uses a special datalog format to generate proper VE values almost everywhere you'd care to operate. You can get the last few cells done manually with the software in another manner. The "autotuning" feature also has an interactive mode where you can use it in conjunction with a dyno (or your logging ride) to drastically reduce the time necessary.

 

I can't quite follow your logic on the "Manual" autotune concept and could not find any other information on the TTS website. I noticed another TTS thread so may there"s some information on it. Thanks

 

GA, check Steve Cole's response. I think this answers your question about autotune...
https://www.hdforums.com/forum/ignition-tuner-ecm-fuel-injection/286036-so-i-m-a-newbie-to-hd-efi-bikes.html

 

I assume you're talking about the following information - It has an Auto tune feature for your application that will allow you to ride the bike and gather information with a laptop. It then takes the collected data and combinds it with the file you have uploaded in the bike to make a new map for you. Do this a couple times and your bike will be tuned in for your modifications. Then if you ever add more just pull it out again and repeat the process for your new modifications.

The narrow-band O2 sensors can only provide very limited AFR data. They can't read anything above or below approximately 14.7 AFR. Even though the AFR is only one part of the required data set it's a very important part. I believe that's why ThumderMax and DTT use wide-band O2 sensors. If I want to set my EFI to run at a taget 13.5 AFR I can't monitor the output with a O2 sensor that won't read below 14.7. That's the part I don't understand.

 

The factory switching sensors are what is used to auto-tune with. Once the VE tables are correct the math takes over and you will get the called for AFR out of the engine. So we start by getting the VE tables correct within the range the switching sensors work properly in first. Then you just dial in an AFR setting you think you want just the same as you would with any other system. The truth is how do you know what AFR is correct for your bike? What one engine wants to be happy is not always what another one wants, so there will be some trial an error with all systems. Also since this is an air cooled motor you cannot run the motor as lean as you might like to for peak power and torque without risking long term engine damage.

 

Part of my problem, in this case, is my obvious ignorance regarding the design an operation of the TTS. I have no idea what the switching sensors are and how they work. It appears you're basically running an open loop system (for the most part) and adjusting VE tables and theoretical AFR based on the data collected by the ECM (excluding AFR input from the O2 sensors). You then download this information to your software package where the maps are modified or manipulated to give you a new map optimized to meet your performance requirements.

 

Switching sensors that are used by just about every auto and motorcycle manufacture out there measure the free O2 in the exhaust just as every model O2 sensor does. No, this is not an open loop system. So what you get is a closed loop feedback of the amount of O2 in the exhaust. This gives you the AFR if you know the fuel being used, in most cases gasoline. We are using the AFR feedback to adjust the VE table so that for a given AFR the tail pipe gives you that AFR. Now that the system is setup properly when you change the AFR table you will get the new result out the pipe. Using a narrow band or wide band sensor does the same thing but it reads slower, cost more and has a shorter life span. They will read over a broader range than the factory switching sensor but are no more accurate when compared in the area that the switching sensor works in.

 

Just a side note about the O2 sensors. The factory O2 sensors are narrow band, i.e. they only read the O2 from idle to about 1500RPM. That is why T-Max replaces the factory sensors with Wide Band O2 sensors which read from 0 - unlimited peak RPM.

Any system that uses only the factory O2 sensors will have no means of reading the AFR above 1500 RPM....translation: they will only be able to adjust the AFR from idle to 1500 RPM and not at cruise or any other engine speed above 1500. They can add fuel above 1500RPM but have no way of judging what the actual AFR is.

Hope that helps.

 

That's mis-information. The wide or narrow bandedness of the sensors has nothing directly related to engine speed in and of itself. What it refers to is the range of measurement the sensor can provide either side of "perfect fuel/air burn". The reason wide-band sensors are typically more desired over narrow-band sensors is because with the wide-band sensors you can obtain/use feedback to the ECM while running mixtures richer than the narrow-band sensors can give meaningful information about. These richer mixtures are typically at higher rpm / more power conditions. For these, you want more fuel than is optimum for complete and clean combustion. If you want to "monitor" and control the extra amount of fuel in those conditions you'll need a wide-band sensor and a fuel management system which can use the information.

In practice this proves to be largely unnecessary. With proper programming in the ECM you can readily get by with the cheaper, longer-lasting narrow-band sensors like installed at the HD factory.

 

Where did you get this information, as it cannot be farther from the truth. As Glens stated above RPM has nothing to do with how the sensors itself works. On most HD bikes the factory runs closed loop up 4000 RPM and most GM V8 engines run closed loop to 4500 RPM with the newest engines now running closed loop to 5000 RPM and full throttle! Whomever gave you this information was screwing with you big time.