Question about 2n1s, what's the deal of both pipes under the cam chest vs one.

I can see the pro and cons, of both pipes under in theory should perform better being closer to equal length, cons they start hanging low-er

​​​​​​​. Any body got dyno sheets to compare,I'm just curious to see some examples

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I don't know what "the deal is" with both pipes going under the cam chest. I assume it's just the design that various manufacturers had the best performance results with. Any 2-1 exhaust is gonna be better for performance than 2-2. I'm running a fat cat and while only the front cylinder pipe runs under the cam chest, I will NEVER run another exhaust. I love the results the fatcat gave me but I don't have a dyno sheet with it being my only upgrade. Slot of popular options are fatcat, basani, thunder header, and Vance and Hines pro pipe. I personally hate v&h but that's just me. I didn't like the look of the basani products, and the thunder header is loud but long, so the rider doesn't get the full sound. That's why I went with the fatcat. I love the look, sound, and performance. Plus it comes with 12 & 18 o2 bungs so if I ever want to run wide and 02s I'm good to go.

 

Look 1/2 way down the page.


https://www.rbracing-rsr.com/exhausttech.htm

 

2 into 1 pipes do that to even out the back pressure in the headers before combining.

 

I like the way headers that wrap around the cam chest look Vs others. It's just my preference, I doubt you could seriously measure any performance differences... all other things being equal.

 

Equal length runners, that maximize the scavenging effect... also equalizes flow between cylinders, because your intake runners are the same length. Why 2-1 pipes work 'better' at low end than 2-2 - they help scavenge each other.

If you look at VE maps for these engines, there is a noticeable difference between front and rear cyl.