Originally Posted by allblackedout
sorry to hijack your thread but why would there be torque loss from the 3"? iv been looking around at different exausts to put on my 11JKU but im not looking to lose any torque or anything. anyone care to explain?
The 3" diameter pipe is larger than the 2.5 inche stock pipe. It's like water going through a hose, if you squeeze the hose the water moves faster, if the hose was to get larger somehow the water would move slower.
The torque comes from "backpressure" a 3.0 inch exhaust should have less backpressure, so in theory it should lose some torque, this lack of back pressure helps in high end power.
We as jeepers want that low end punch. High end is nice, but for our purposes low end is far more useful.
I should also mention that I had the 2.5" inch Afe exhaust with the muffler in the far rear of the truck, the 3 inch I had was the muffler relocation unit. That means that the muffler was relocated under the driver's seat, so the 3.0 inch tube was only for about 5 inches until it hit the muffler.
Afe also makes a 3 inch exhaust that has the muffler all the way in the stock muffler location, that means that the exhaust would travel the entire length of the truck before hitting the muffler.
The relocated muffler unit, may be the reason there is no torque loss with the 3 inch exhaust unit. (as the exhaust really isnt going very far before it hits the muffler)
Ill post some pictures so you can see what I mean about the distance between the muffler and the stock 2.5 inch pipe.