Does it really matter?

[robthezombie]

Id like to be able to learn this machine so I understand how it runs and runs most efficintly. So ive been reading around on here about back pressure and how it affects the bike. Im not a mechanic so I dont fully understand the whole issue. So I would like to propose some cases and hear what you think. Does the muffler, honeycomb, or both add to the backpressure?
1. Megaphone exhaust (Hotbodies) with a y-pipe and cats removed.
2. Hotbodies exhaust with y-pipe, but honeycomb still in.
With those two set ups would it be wiser to keep the cat to have some backpressure or does it matter?
I know this exhaust basically has no back pressure so I used it.
I appreciate anyones help trying to figure this out.

[ridick_bowen]

Buy and powercommander and leave your exhaust alone. Better mod IMO.

[cheefar6]

Originally Posted by robthezombie

Id like to be able to learn this machine so I understand how it runs and runs most efficintly. So ive been reading around on here about back pressure and how it affects the bike. Im not a mechanic so I dont fully understand the whole issue. So I would like to propose some cases and hear what you think. Does the muffler, honeycomb, or both add to the backpressure?
1. Megaphone exhaust (Hotbodies) with a y-pipe and cats removed.
2. Hotbodies exhaust with y-pipe, but honeycomb still in.
With those two set ups would it be wiser to keep the cat to have some backpressure or does it matter?
I know this exhaust basically has no back pressure so I used it.
I appreciate anyones help trying to figure this out.

dont quote me on this, but this 'back pressure' is created by having an exhaust header attached.
If you were to run with your exhaust off, the exhaust gas would be free to exhume into the atmosphere with nothing affecting the flow other then the valve.
when a exhaust is attached, the gasses coming out, must push all of the gasses already filling the exhaust, which creates pressure, like blowing through a straw.


any aftermarket exhaust system will create a small amount of 'back pressure' so your good a ny way you choose to go, although removing the catalytic convertor, will cause the bike to run with incorrect AFR, so fuel management (like the pc3) is recommended.

[Eric10301]

Just remember if you remove the Cat you will need a fuel controller. If you don't want to buy one that makes the decision easier. Here is all the info you really need http://www.r6-forum.com/forums/showthread.php?t=142421.

[robthezombie]

OK so if I'm understanding correctly the exhaust( from header to the tip) is what cause the back pressure and the can only affects it a small amount. So having the cat and muffler cause back pressure by causing there to be more pressure to expel the fumes. And that's why a slip on, on this machine is somewhat pointless?

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[cheefar6]

Originally Posted by robthezombie

OK so if I'm understanding correctly the exhaust( from header to the tip) is what cause the back pressure and the can only affects it a small amount. So having the cat and muffler cause back pressure by causing there to be more pressure to expel the fumes. And that's why a slip on, on this machine is somewhat pointless?

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the slip on will only change the pitch of the exhaust note, by having different materials/shapes/and amount of sound dampening material (like fiberglass) used in the can.

also the path and size of the exhaust will affect gas flow and sound, unless your racing world class, i wouldnt worry about the "performance gains" company claim to have by running this can with that exhaust, the differences are minimal and difficult to measure correctly.

removing the catalytic convertor lets the engine 'breathe' easier and more efficiently, at the expense of emissions, so just removing the cat will give performance gains, but then going graves and 2bros, or wahtever exhaust you want will be minimal, they are all cat removed.

[Ryan5544]

[Tdub]

Originally Posted by ridick_bowen

Buy and powercommander and leave your exhaust alone. Better mod IMO.

So in other words, you don't know an answer to his questions...

[Powerstroke87]

Originally Posted by Ryan5544

Fcuking jabronis

[robthezombie]

OK thanks for the insight. I think Ive got that figured out now. If not for this forum I'd probly ruin my bike doing something some idiot on the street told me to do. I swear noone hear even knows what a powercommander does. They throw on a full system and go. I appreciate everyone who chimed in

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