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Discussion Starter · #1 ·
So ive been talking with akrapovic and apparently if you run there full system with there cat and baffle in it is safe to do so without a tune. Your bike wont run lean.. any thoughts on this.. has anyone done this and ran it on a dyno to see? They said once you remove the cat then you will need a tune or should get a tune..
 

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Discussion Starter · #2 ·
Anyone have any thoughts on this id love to hear what people think.. i really hate how quiet the bike is but i definately dont want to start messing around with dyno and adjusting fuel on a brand new bike i figured that this may be an option??
 

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There are a few on this site running that system without doing anything more than installing the pipe. And they all claim it's go to go without a flash. If you dig hard enough or search with Google you can see for yourself.
 

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I got my Akro carbon and PC5 at the same time. Installed the exhaust first just to see how it ran and it ran alright, not much different from stock besides sound. I wish I would have gone custom flash now and will say if you want to get anything out of that exhaust you definitely need to get someone to flash what you have. I do love the grumble of that exhaust though. On a side note if you get a controller you might want some block off plates, I believe you can tune this problem out with a flash however.
 

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Can someone please explain to me how an exhaust, a system designed for "post-combustion", after the Air-Fuel calculations can lean out a mixture? The only lean-ness occurring is the PAIR system injecting fresh air into the exhaust causing decel pops, adding a touch of white to your spark plugs.

Disable the AIS valve or install block-off plates. Still no leaner than before...
 
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Discussion Starter · #7 ·
Yeah i think the popping and flames people see is from that stupid air injection crap. I dont see how its doing any harm or leaning it out.. i could see if i took snorkle out and did an airbox mod but if it isnt brwathing more air in the mixture should now change that drastically
 

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A free flowing exhaust can, will, does make a bike run leaner. It reduces restrictions, which allows the motor to move more air. More air, more lean. This isn't even debatable, as it has existed for decades.

I personally cannot see the point in trying so hard to avoid an $80 tune, after buying an $800 exhaust, to make it run optimally.
 

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A free flowing exhaust can, will, does make a bike run leaner. It reduces restrictions, which allows the motor to move more air. More air, more lean. This isn't even debatable, as it has existed for decades.

I personally cannot see the point in trying so hard to avoid an $80 tune, after buying an $800 exhaust, to make it run optimally.
So in theory, a less restrictive post-combustion system is going to allow the engine to "inhale" more air volumetrically. The air drawn into the cylinders is created by a vaccum, the rate of vaccum pressure is static, unless bore/stroke or compression ratio is changed.

The engine is going to inhale the same amount of air, but velocity (often confused with back pressure) in which the exhaust stream exits the system will be reduced through installing a less restrictive exhaust system. How does that equate to a greater volume of air entering the cylinders without a change to bore/stroke/compression ratio, or adding a form of forced induction?

The only relative information I've found on an exhaust system leaning out the A/F ratio is whether or not the ECU freaks out because the o2 sensor in the exhaust stream is now reporting more flow, and even then the ECU's native response will be to richen the mixture. There's a reason exhaust manufacturers claim no tune needed and considering Japanese bikes are intentionally lean from factory for emissions / mpg reasons... We would see a lot of threads in the sportbike community titled: "Help, aftermarket exhaust seized my motor!". Thus requiring exhaust manufacturers to require a tune when purchasing their product.

This isn't an attempt to ruffle any feathers, but I would like to push my peers to think outside the box on these types debates :D

I completely agree with a tune or flash to take full advantage of that new shiny performance part. Especially when guys like vcyclenut are doing it for $80 :D
 

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Discussion Starter · #12 ·
I dont know how to do a flash or where to go for a flash or what a flash even is lol sorry im a complete noob when it comes to this stuff
 

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Vcyclenut is a supporting vender on this forum. Kev xtx
Also makes a O2 controller that deals with the lean condition below 6000rpm. I don't care about this technical talk all I know is those two things with a akra.pipe make my bike smooth down low and scream up at the high end.
 

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Of course Akro says it's fine without a tune, the system is designed with a catalytic converter to be EPA compliant and they couldn't sell the system as street legal if the system needed post installation tuning. However, a reflash designed for the Akra system will have the bike working optimally (more power, better throttle response) without regard to EPA restrictions, so will a reflash on a completely stock bike. A vcyclenut flash is the best bang for the buck on these bikes.
 
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Buying an exhaust, with no intention of correcting fueling, is like buying one breast implant. It may look different, but it isn't nearly as fun.

Almost EVERY EXHAUST manufacturer says that their exhaust will run with stock fueling. Yes, it will run... It will start, and run, and not do damage. Will it run well? No. After numerous "no mapping" required exhausts, on numerous bikes, I can tell you the 09 is no different. It will not run WELL without a tune.

Do what you want, it's not my bike.... But don't believe half truths.
 

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Buying an exhaust, with no intention of correcting fueling, is like buying one breast implant.
Nothing like your girl coming in 1st AND 3rd in the wet t-shirt contest!
 
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