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+--- Thread: Back to Stock Muffler (/showthread.php?tid=5172)
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RE: Back to Stock Muffler - PowerDubs_imp - 06-17-2018
(06-17-2018, 08:19 AM)beardyweirdy@me.com_imp Wrote: " Note- it just creates the map, it does not adjust the ecu file / parameters being used on the fly."
Is that right? I've always wondered and I've heard both that it does and that it doesn't....
I know the fuelling feels better with the Auto Tune on.
Acc. It might adjust on the fly. I was looking at putting Target AFR's in the 0% throttle line earlier, but Dynojet advise against it as it can upset the idle/over run and cause surging I think. They advise only adjusting the Fuel manually in the Fuel map. If the Auto Tune wasn't adjusting the AFR on the fly, then this wouldn't matter. I'm not 100% sure either way tho and just trying to work out if it does adjust as you ride...
They don't really make this clear anywhere. I just finished installing everything except the cams, but I haven't started the bike up yet.
Once I play with it, I guess I'll know. Once I tune it as it sits, I am headed back to the dyno again to see what I get before the cams.
I suppose the AT could do it's thing live- and the 'load' function would just push a static map to the power commander if you want to take the autotune out- which I probably will once it is tuned.
RE: Back to Stock Muffler - Aussieflyer - 06-17-2018
Mine is a simple understanding of these really cool accessories, here goes ...
Exec summary ...
The Powercommander with Autotune does make fuelling adjustments on the fly to constantly keep the engine running at the desired air fuel ratio.
Now some detail including facts, hypothesis and hopefully not too much bulls#!t
The Powercommander (PC) 'massages' the output of the bike's ECU to provide revised fuel delivery across any or all of an engine's rev range. Massaging is done by way of adding or subtracting a fraction of fuel from the bike's pre-programmed fuel delivery. The PC refers to a user defined fuel map which stipulates the fuel correction percentage for each engine RPM (in 250 RPM steps) and each throttle position (in 5% steps), e.g. if the PC is told to provide +10% fuel at 4000 RPM with throttle position at 50% then the resultant fuel delivery is whatever the ECU was going to deliver PLUS an extra 10%. I stand to be corrected but I think it works by altering (extending or shortening) the electrical signal to the injectors by the percentage prescribed in the fuel map.
The Autotune device in conjunction with a Wide Band O2 sensor constantly measures the exhaust gasses to determine the actual air fuel ratio (AFR) of the engine. Plugging the Autotune into the Powercommender now creates a new 'tool' that knows what the AFR is at any moment in time AND knows how much fuel is being delivered to the engine at that point in time, at those RPMs and at that throttle position. This new tool now needs a second reference table to advise it on target AFRs prescribed by the operator for given RPMs and throttle positions. The Autotune and the PC then work together to continually adjust the fuel map by adding or subtracting fuel to achieve the prescribed AFR. It tunes as you ride and stores the adjusted fuel map for the operator to view through the software. The adjusted fuel map can then be accepted by the operator meaning it now becomes the new baseline. Soooo, if after a ride you see that the Autotune has made corrections to fuelling and you accept the new fuel map, then on the next ride the Autotune may not need to make any further adjustments. Dynojet state that it's a good thing to accept the new values because the nearer the baseline fuel map is to delivering the prescribed AFR the better. I suspect that's because there is time taken (nanoseconds) to measure and make fuelling adjustments so the smaller the adjustment the more accurate the fuel delivery.
I've had this set up on my bike for the last year or two and experimented with switching the Autotune in and out as I rode to feel the effects - I installed a small toggle switch on the left switch block. A super obvious benefit of the Autotune is how it adjust fuelling when riding from low to high elevations and vice versa. With 20:20 hindsight I think that if you plan on making only one set of modifications to intake and/or exhaust then it may be simpler to just fit your new components and get the bike professionally dyno tuned. If you're planning on experimenting with modifications or using different fuels then a PC with Autotune may be good idea. They are fun to play with.
RE: Back to Stock Muffler - beardyweirdy@me.com_imp - 06-17-2018
I'll buy that for a dollar....
Great explanation and I concur.
Back to Stock Muffler - PowerDubs_imp - 06-18-2018
Yup. That nails it.
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RE: Back to Stock Muffler - PowerDubs_imp - 06-18-2018
Put the bike all back together after work tonight, fired it up, was able to connect to the PCV & Autotune on the laptop to verify everything was working....then it started raining.
Definitely has a little more bark with the arrow header and the modified velocity stacks.
I'm sure I'll get it out and play more some time this week.