Whats the best performance mufflers for my 2015rgs with a dealer installed stage IV. Presently have V&H head pipes with cfr mufflers.

 

Ooh. Bad from a performance perspective.

Probably want to go 2-1: Fatcat, Fuel Moto, Supermeg, V&H pro-pipe, etc.

Others will say you could go 2-1-2, but you went with a stage IV presumably because you want the performance, so it makes more sense to go with a 2-1, why throw out any of the ponies you just bought?

 

Not trying to hyjack this thread, but is the best "performance" exhaust always two into one? True duals are not?

 

Generally yes, but its as much about where peak power is made. True duals will peak further to the right in the torque curve.

 

Ok thanks. I'm ignorant when it comes to bikes.

 

um, the 2/1 is a real advantage on a smaller framed bike such as a dyna, sporty etc.

the 2/1 will generally help with low end power- but only if the other parts of the motor can take advantage of that.


the 2/1/2 on a touring frame provides a large volume in the exhaust tract and will combine scavenging ( the prime benefit of a 2/1) and allow high volume and high velocity exhaust gas flow at high rpms ( the prime benefit of 2/2 or straight pipes).

a less abrupt advantage in any particular part of the dyno chart..but a general gain at all rpms- less "peaky"

The HD stage 4 kit is designed for the large volume of the 2/1/2 headers and 2 mufflers.
OP I think you'd do well with that.
look at the dyno chart for the stage 4 in the screaming eagle catalog and you'll see potential power peaks at 4000 then falls off


the volume of the tract is important.
an illustration of this might be a dyno chart for a Dyna model vs a Touring model.
Both use the A same motor- the touring model will generally show an even 3 hp increase in power along the charts


the 2/1 is great on a smaller framed bike where the stock exhaust might not have the volume of a touring exhaust.

My FXRP has a 2/1 ( supermeg) for the past 25 years- in conjuction with compression, cam, headwork intake and ignition, the weight and the gearing----this is a pretty quick 80"...but at 5200+ rpms the exhaust is the bottleneck...this is why I have a 15% overdrive

 

I'm not sure what the size of the frame has to do with it. Same engine. Plenty of touring bikes taking advantage of the benefits of 2-1

 

If you have the true dual style VH head pipe, they are pretty bad performers with your type motor. The Fuel Moto SPC 2-1-2 headpipes are a great performer at a good price for a coated headpipe, but there are others that work well too. I haven't heard anything good about the cfr's regarding performance.

 

since the "dealer" did the build your asking the wrong question, I would be asking who's the best tuner in my area.