The PC III-USB does away with the O2 narrow band original sensors and leaves the engine in an open loop mode.
The ThunderMax installs wide range O2 sensors and works like the standard bike, that id closed loop by reading the exhaust gases and can work with higher fuel mixtures (13 or lower stechiometric values).
My question is, what happens with the SERT? does it still use the original O2 sensors or does it do away with them? Of course I'm taking about the latest 07-08 bikes with dual O2 sensors; in my case an FXDC 07

 

SERT does not remain on your bike like the others that are plugged in down stream of the engine's computer and remain permanently attached to the bike - whereas SERT is plugged in to your engine's computer to tune your bike via a PC to change various parameters in the bike's ecm (something like 260 different ones I believe) - it has nothing to do with the O2 sensors which remain intact as originally designed since it is modifying the bike's original settings.

 

Dear Chipstah,
I know the SERT is a programing toolthat is unplugged from the bike once you are done with the adjustments, but if the O2 sensors remain on the bike and connected as usual, how can you modify the ratio between air and fuel if the O2 sensors that come from the factory are narrow band and will not accept other than 14.7 or similar (14.7 parts in weight of air per 1 in fuel)?
That is what I don't understand in this SERT business. And that is why ThunderMax installs wider range O2 sensors...
BR, and thanks,
Spanish Flyer

 

OK, ya got me - way too technical!! Afraid my knowledge is more rudimentary. What I think (and I could be wrong), is that the SERT changes parameters (among others) that add fuel to the what the O2 sensors are sensing throughout the rpm range from idle up to redline, thus changing the air/fuel ratio. Air is coming in from the intake, and the O2 sensors merely sense what is happening (?) Perhaps someone else like Trotter can chime in with some more useful technical info in this regard??

 

I think SF asked an excellent question. Deserves an expert ansker.

Where's that damn Skip when you need him??

DougJ

 

Yeah Chip, but it's way more involved than that.
First picture below is part of the answer for Flyer.

Like I say though this is only part of the overall picture.

Flyer, Let me know if you want to have a look at the user manual.
Second picture is just an example from the user manual.

I can email it to you. 2600 KB, it is a pdf.

mud

 

Hi guys,

Let's see if wisdom and experience maketheir way to this message.... in the mean time, I´m sure there are many around with 07's and 08's with the Race Tuner in their wardrobe or in a box in the garage.... maybe they'd care to take a look at their bikes and see if the O2 sensors are still connected or by-passed.... It would give us a hint.

Thanks for the answers; now let's see if we get to the bottom of this question.

 

The way it was explained to me is that the narrow band o2 sensors can only make small adjustments and not at all throttle settings....I know they dont do anything at 100% but I dont know where else....It does not matter what the a/f is, be it 14.7 or 10.7..they will still work just in small amounts.

The wide band can make very large changes...and with the tmax it will change throughout the entire throttle range..

Hope this helps some what, I have a hard time explaining myself alot of timesalso this is all second hand information from a few people, including azippers rep at a bike rally,I have talked with.

 

I have wrtten the best performing map for my SERT by using my "butt dyno" and simply looking at the SE performance maps and increasing the AF tables and fuel tables by one increment along the same original power curve.....then saving & installing the map and go riding. After about 20 tries and real subtle adjustments you can get the bike running real smooth with almost no poppong and a smooth torque range that runs from about 2500 to 5000 rpm. No more surging, popping. The fuel economy suffers about 10% but the plugs look fine and the carbon buildup inside the exhaust pipe is gone. THAT SAID.....I wouldnow buy the Thundermax because it is a step better than the SERT in technology. It tunes itself. It wasn't available when I got my SERT or I would have bought it.

 

Find your answer yet??

Keep us updated.

mud