I posted similar thread on Sportster forum, but only received a few responses. Thought i'd try my luck here.

I'm riding a Nightster XL1200N, Installed PC V (pre-mapped by Fuelmoto) when I did my stage 1. Relatively happy with the bike's performance, however I'm experiencing some occasional popping when I come off the throttle in second gear. On top of that, I'm now averaging around 37-38 MPG (a loss of approx 5 mpg). I was hoping that running the Dyno Jet Autotune module might fix the popping, and also give me some MPG back. Thoughts?

Also wondering, does the autotune eliminate the need to tweak your map?

 

Aototune works best when your base map is as close to your bike characteristics as possible, less hunting.

You may get some mileage back, but not much. They have to run fat because of sensor inaccuracy.

If you want mileage and a smooth tune you need to go to a TTS tuning kit or take your PCV to a tuner and tell him you are looking for mileage. You won't get as good as the TTS but it should be better.

 

Wideband Sensor inaccuracy? Please show me some supportive data on this one.

 

The decel popping is a characteristic of an open, straight thru exhaust which is caused by reversion in the exhaust system and tuning this out is very straight forward. As far as your fuel mileage we can also revise a map that will help out no problem. The Auto Tune would also be another option and is completely capable of fine tuning for your combination, it has been well proven to be extremely accurate. For support you can contact us at 877-729-4754 and we are here to help

 

No question your products work well, provide excellent performance.

But as has been discussed on this and other forums at length all you just need to read is the Boche supplied data sheets that specify under what circumstances the sensors can be accurate and for how long. Those parameters are no where near what you get routinely in an HD application. They clearly state that when not calibrated regularly or used at the proper heat and pressure they are not all that accurate in practice. And when abused, tend to loose their accuracy quickly. Today in practice, a good guess based on engine characteristics provides just as accurate A/F mix as a properly set up HD wide band sensor systems. (note that this may not be true for more controlled vehicle applications, like some cars. The aircooled HD motor with short exhaust pipes is a challenge.)

So the question perhaps becomes value, is the extra expense and installs worth the trouble, given that they just work well enough. Consumers that come here for advice and discussion may appreciate that there are several different views and every system has one compromise or another.

Spouting off technical details makes for good marketing literature, however. Every product does it, just trying to weed through the chaff here.... I guess.

 

You have been clearly following TTS/Steve Cole's views and opinions and yes I do also recommend reading the Bosch data sheets which provide excellent information. Wideband sensors are very well proven, they are used in virtually every level of motorsports as well as extensive OE applications, many of which are far more demanding than an air cooled Harley. Your statement of "Today in practice, a good guess based on engine characteristics provides just as accurate A/F mix as a properly set up HD wide band sensor systems" clearly shows that you do not have a full understanding of how these system work. I would love to be able to show you first hand the accuracy and usefullness of the different tuning platforms and equipment we work with here every day.

 

Coldcase, did the OP ask about TTS? Are you the head of marketing for Steve Cole? Give it a break and just answer the friggin' question! Please?

You don't need a dyno-tune to obtain good mileage with a PCV. All it is doing, and this is the way TTS functions as well, is dictating a pulse-width for the injectors and ignition timing instructions based on the tuner's input. If you get it right it is right, period, and one won't do it any better than the other. All you are doing with either is dictating the right pulse-width applied at the right time, and that's the bottom line. That's the fundamental mission of a tuner. OTOH, some can do it without a dyno tune, and if cost is a factor this may play into the needs of the rider.

Without AT you can guess at a mileage tweak as well as you can with the flash-based tuners, and I did it before upgrading to AT, but AT is a precise proposition. You apply the AFR's you want in 250 areas of the RPM/TP grid and just ride.

You claim TTS can "do it better," so as long as you've hijacked this thread why not explain to us in detail why you think so?

 

Since you keep harping on this, why don't you show us. Can you provide links? If you do, be sure there is a date that can be clearly seen, as this is 2010, not 2000.

Why not? Where is the evidence?

Links? Evidence?

No, you are promoting your favorite tuner yet aren't giving us any real evidence. It's time to produce it.

 

For what it's worth, here's what the folks at DynoJet came back with:

Decell popping does not necessarily mean that the bike is running lean or rich. It is simply unburnt fuel being released into the exhaust and igniting in the pipe.

 

Jamie, as always you are an incredible help! I may be contacting you for another map if I decide I want to try to get some of the MPG back. Good news is I haven't had any popping in the past 2 days. So maybe things are running as should.

Good thing, because the folks at DynoJet say there have been reports of some compatibilty issues with the Autotune module and my setup (sportster with v&h sideshots), because the sensors stick out more than stock.