The Myth of Backpressure

[geresti]

I thought I heard that if you change exhaust you have to add power commander V or something similar. Did ya'll do anything like that with the addition of your new exhaust?

[ROADKILL]

I thought I heard that if you change exhaust you have to add power commander V or something similar. Did ya'll do anything like that with the addition of your new exhaust?

If you just change the exhaust you don't need to do anything...when you change the air you do.

[geresti]

I thought I heard that if you change exhaust you have to add power commander V or something similar. Did ya'll do anything like that with the addition of your new exhaust?

If you just change the exhaust you don't need to do anything...when you change the air you do.

the guy that I bought my bike from told me that yamaha told him that he needed to add the power commander after adding the V&H 2-1 big radius to make the bike running correctly and to keep the warranty valid. There is no air kit on my bike.

[geresti]

I thought I heard that if you change exhaust you have to add power commander V or something similar. Did ya'll do anything like that with the addition of your new exhaust?

If you just change the exhaust you don't need to do anything...when you change the air you do.

I just found this article http://www.motorcyclemart.com/newmustknowexhaust.htm

[Mr. T]

I thought I heard that if you change exhaust you have to add power commander V or something similar. Did ya'll do anything like that with the addition of your new exhaust?

If you just change the exhaust you don't need to do anything...when you change the air you do.

the guy that I bought my bike from told me that yamaha told him that he needed to add the power commander after adding the V&H 2-1 big radius to make the bike running correctly and to keep the warranty valid. There is no air kit on my bike.

You were misinformed... on both parts.  Needing the power commander and keeping your warranty valid.

You can swap out your pipe and don't need a PC unless/until you also open up your intake (big air kit).

[geresti]

I thought I heard that if you change exhaust you have to add power commander V or something similar. Did ya'll do anything like that with the addition of your new exhaust?

according to the article that I read you are mistaken. It says you DO need the power commander if changing exhaust. Check out that link in my previous post
If you just change the exhaust you don't need to do anything...when you change the air you do.

the guy that I bought my bike from told me that yamaha told him that he needed to add the power commander after adding the V&H 2-1 big radius to make the bike running correctly and to keep the warranty valid. There is no air kit on my bike.

You were misinformed... on both parts.  Needing the power commander and keeping your warranty valid.

You can swap out your pipe and don't need a PC unless/until you also open up your intake (big air kit).

[TRaider_John]

Changing the pipes does not mean that you NEED to put in a fuel management system, but you may WANT to.  The Yamaha guy is correct in that he told him "that he needed to add the power commander after adding the V&H 2-1 big radius to make the bike running correctly."  The bike will run without one, but to optimize performance, you will want one.  Read the first post in this thread.  If you change the exhaust, you probably need to tune the engine, too. 

Changing pipes without fuel management does not void the warranty.  My dealer does it all the time. You will find many of our forum members are running that way without a problem.   

[Deyv]

I thought I heard that if you change exhaust you have to add power commander V or something similar. Did ya'll do anything like that with the addition of your new exhaust?

If you just change the exhaust you don't need to do anything...when you change the air you do.

the guy that I bought my bike from told me that yamaha told him that he needed to add the power commander after adding the V&H 2-1 big radius to make the bike running correctly and to keep the warranty valid. There is no air kit on my bike.

And this is why we call them "Stealerships"

[geresti]

Changing the pipes does not mean that you NEED to put in a fuel management system, but you may WANT to.  The Yamaha guy is correct in that he told him "that he needed to add the power commander after adding the V&H 2-1 big radius to make the bike running correctly."  The bike will run without one, but to optimize performance, you will want one.  Read the first post in this thread.  If you change the exhaust, you probably need to tune the engine, too. 

Changing pipes without fuel management does not void the warranty.  My dealer does it all the time. You will find many of our forum members are running that way without a problem.

Supposedly he had all of that done but I believe something else needs to be done because mine tends to backfire quite often and I don't think that is right. I will take it to a mechanic for my 1000 mile check-up and see what he has to say. Does your bike pop or back fire any? Mine seems to do it when I shift.

[TRaider_John]

If you are running a PCV, put 30 in the first column of the table and see what happens.  If you don't get popping, try reducing it a bit, if it still pops, try a bigger number. 

That fix comes from the guys at Dynojet and it works on most bikes.