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Do I need a tuner? I have a stock 2011 FXDC and hate the factory exhaust. I got a good deal on a set of V&H 2 into 2 big radius and was wondering if I can just change out the exhaust without having a tuner. I plan on getting the tuner and stage 1 after the 1000 mile service or at the service. Thanks
 

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Although it is not ideal, you can run the pipes without the "tuner". But keep in mind the bike most likely won't run the greatest until you do tune it.

If you do this; keep in mind that your bike will then be trying to push out more air than it is bringing in. So you will most likely lose torque especially, and horsepower too.

Best thing you can do is just wait until you are ready to do the entire system. I know patience is a hard thing to manage but, it will be worth the wait in my opinion. I know you want to change the sound but when you twist that throttle open and the bike don't respond good, that can be very disappointing.

But again, yes, it can be done.
 

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"Jane you ignorant slut!"
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These bikes already come lean. If your pipe turns yellow (like mine did) from being lean I hope you like that look. Also a lot of people here said it would be fine too, it wasn't.
 

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here is a thread where I show just what the AFR looks like with a pipe swap and no tuning ,just the way it would be if you just bolted it on and rode it. if you know anything about what the AFR should look like you can see it is very lean. anytime you help the motor breath better it will lean it out somewhere. this was with a stock A/C and just a pipe swap. so even though the A/C wasent changed ,the exhaust still made it breath better with the "air" it had.

http://www.v-twinforum.com/forums/e...tra-do-i-need-remap-if-i-put-2-1-stock-c.html
 

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This is the a/f reading I had before/after adding just slip on mufflers. No tune. No other mods.

This is not a WOT run but a roll on.

Note that the lines are virtually on top of each other.

YMMV. This is my experience.
 

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looks like 15.0 ish AFR at that particular RPM/ T/P KPA (light load)
lean either way.IMO
 

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Oh I agree it's lean. I just meant to show that in my case adding the slipons didn't make it more so.

I was watching the a/f readout during the session. I could see the ecm adjusting fuel....it would jump around from about 14.2 up to 14.9 and then steady in around 14.6/14.7.

WOT runs were different of course.
 

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Oh I agree it's lean. I just meant to show that in my case adding the slipons didn't make it more so.

I was watching the a/f readout during the session. I could see the ecm adjusting fuel....it would jump around from about 14.2 up to 14.9 and then steady in around 14.6/14.7.

WOT runs were different of course.
that is really good closed loop fueling. most will go leaner than that.
but even tuned they never get any richer than 14.4 14.5 in closed loop no matter what you do. still too lean IMO.
you were at light throttle / light load so you could get by with 14.6 14.7 there for short periods.
interesting graph....one other thing to consider. on a roll on there will be short bursts of accel enichment also.that is why you saw the AFR go to 14.2 at times.
 
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