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[beardyweirdy@me.com_imp]

Hey All,

I've been tinkering and refitted the OEM Muffler to my bike.

I've been running with my lovely Over end can but but as I'm planning a trip or two soon, with a pillion, decided that a bit of peace and quiet might be nice ;-)

I'm actually loving the original can again! It's so smooth and it just purrs along. I'm running it on the end of my Arrow Cat Free 4-1, which was already fitted to the bike.

I've got a PCv and Auto Tune fitted, so I'm not too concerned about the fuelling, but wondered which way, if any, I should expect to see the fuelling go?

The flow of exhaust gas, I'm assuming, must be restricted with the Stock Muffler. Should this make the bike run lean or rich?

I ask as last time I went to the Dyno, after fitting air box mods and a cat free header with the Over muffler, I expected to see the bike running lean and was told that it was the opposite. The person at the tuners said that opening up the air box and exhaust would make the bike run rich and they'd had to lean it off. Not what I expected to hear.

So, that said, should I be expecting to richen it up after fitting the restricted, stock muffler?

What do you reckon?

 

[Bheezy27403_imp]

Hmmm, that's odd. I'm no expert but opening up a motor to breathe better should lean it out. Add more air, need to add more fuel.

 

[beardyweirdy@me.com_imp]

That's what I would have thought....

I'm giving it a few miles and then I'll look at the Auto Tume trim tables, to see what it wants.

 

[dbarkdoll_imp]

What exactly does the Auto Tune do? Just reads and logs air/fuel mixture for you to later download on a computer?

 

[beardyweirdy@me.com_imp]

What exactly does the Auto Tune do? Just reads and logs air/fuel mixture for you to later download on a computer?

It measures the Air/Fuel mixture via a Wideband O2 sensor in the exhaust pipe and adjusts the mixture, via a Power Commander to achieve the Air Fuel Ratio you have specified. You set up your Target AFR's via software on a computer that you connect to the Power Commander.

It's a nifty system.
On another note, I took it for another spin last night and checked the Trims it had suggested for the fuel and it was asking for the fuel to be reduced and the mixture leaned off. Makes sense.
I'm loving the 'New' quiet pipe, by the way.... Noisy exhausts are so last year ;-)

That said, and I might just be being paranoid, but I'm sure I've had more people step out in front of me since I quieted her down.

 

[PowerDubs_imp]

What exactly does the Auto Tune do? Just reads and logs air/fuel mixture for you to later download on a computer?

The power commander box allows you to adjust fuel +/- at the different rpm and throttle positions. This graph of data points is commonly referred to as the 'map'. The bike ecu has a map for the fuel, and also one for the ignition although this only adjusts the fuel map.

So the 'PC' allows you to change the map, but has no way of knowing what to do and where unless you put the bike on a dyno and are able to read it's air/fuel ratio at the various rpm and load.

The auto tune module plugs into the power commander on your bike, and you also install a wide band o2 sensor in your pipe. While you ride it looks at your a/f ratio from the wbo2 sensor and creates a modified map for you based on your 'target' a/f ratio you are requesting. Note- it just creates the map, it does not adjust the ecu file / parameters being used on the fly.

Once you return home, you can plug in your laptop and view the new suggested map the auto tune created. If you like it- you can then apply it (overwriting the existing map being ran). You then go ride again, repeat the process and see what the auto tune thinks the next time.

Given that you will always have differences in the rpm you ride at, and the throttle position for each rpm - it can take several rides to get a well adjusted map file dialed in.

Hope that helps. And yea- it doesn't 'auto' tune per say, at least not 100% on it's own. Still a fair amount of involvement- but way better than rejetting carbs, and looking at spark plug color.

 

[dbarkdoll_imp]

That is very cool. Thanks for the responses guys, very good job of explaining it. Any idea how much the auto tune module and o2 sensor cost?

 

[PowerDubs_imp]

Not cheap. Off the top my head if you shop around for both pieces you’re still looking at somewhere between 550 and $600. And you still need to have the O2 bung welded into the exhaust.

Basically both of these parts only exist for people that are making major modifications. If you are only putting on a different muffler than the bike will run fine as is.

If you want to change to a header to get rid of the cat, then you can buy just the power commander by itself or send your EC you for a reflash for somewhere around $300 if I remember correctly.


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[beardyweirdy@me.com_imp]

" 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...

 

[dbarkdoll_imp]

Not cheap. Off the top my head if you shop around for both pieces you’re still looking at somewhere between 550 and $600. And you still need to have the O2 bung welded into the exhaust.

Basically both of these parts only exist for people that are making major modifications. If you are only putting on a different muffler than the bike will run fine as is.

If you want to change to a header to get rid of the cat, then you can buy just the power commander by itself or send your EC you for a reflash for somewhere around $300 if I remember correctly.


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Noted. Thanks. I’m not planning on doing any of this at the moment btw, but it’s good info to know. I’m happy with my Arrow slip-on and stock everything else at the moment, as is my wallet. One day maybe! Prob just pick up a MT09 or Street Triple if the need for speed gets any worse tho.

 

[PowerDubs_imp]

" 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.

 

[Aussieflyer]

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.

 

[beardyweirdy@me.com_imp]

I'll buy that for a dollar....

Great explanation and I concur.

 

[PowerDubs_imp]

Yup. That nails it.


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[PowerDubs_imp]

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.