Cut off cat?

[JollyGreen]

So....running duals out of the muffler, even if it's the same as stock pipe is bad? I would think once it goes through 2 cats and passes the muffler, 4-5 ft of pipe wouldn't make that big of a differance. So keeping the stock setup minus the 55 gal drum GM calls a muffler (DI/SO with say...a magnaflow) is much better? Just asking because I'm ignorant to this.

 

[Chris]

Dual pipes are fine, as long as there is some sort of crossover to balance the exhaust. IE - X pipe, H pipe, 2>1>2 muffler, etc

 

[TLoud]

are you freaking kidding me? obviously you dont own a motorcycle.

 

[TLoud]

I'm not saying the amount of back pressure is going to be so greatly affected thay it will ruin an engine but a baffle restricts the flow of exhaust which creates back pressure, removing them allows more flow decreasing back pressure making it louder and generally having a negative effect on engine performance.

 

[JollyGreen]

Dual pipes are fine, as long as there is some sort of crossover to balance the exhaust. IE - X pipe, H pipe, 2>1>2 muffler, etc

Behind the cats but before the muffler, right?

 

[Chris]

I'm not saying the amount of back pressure is going to be so greatly affected thay it will ruin an engine but a baffle restricts the flow of exhaust which creates back pressure, removing them allows more flow decreasing back pressure making it louder and generally having a negative effect on engine performance.

Dude, slow down. Listen to what you're saying. I know what you're trying to argue passes the common sense test, but if everything worked like common sense says it should then airplanes wouldn't fly.

The baffles in the exhaust create the effect of reducing the pipe diameter over its length. That in turn produces higher exhaust velocity, which is a hallmark and beneficiary of smaller diameter pipe. That aids in effectively pulling exhaust gases from the cylinder on the overlap stroke. The loss of power from a fully open pipe is a direct result of MUCH lower exhaust velocity, which will greatly diminish cylinder scavenging. There's been a lot of misinformation out there for years and it gets passed down literally through generations. Sometimes things aren't as they seem, this being a perfect example. Once you dig a little deeper you'll realize what you have always thought is 180 degrees the opposite of reality.

 

[TLoud]

so now your basically arguing the same thing in different words... So now i am done with this thread.

 

[Chris]

Negative ghostrider. I only recanted a proven physical theory in the hopes of educating a horde of simpletons.

 

[TLoud]

lmfao now i understand

 

[RHamill]

I just want my truck loud, and running right. Cars have been around since the LATE 1800s, I'm not concerned 1 bit about the environment crumbling and all of us dying because people don't slap a couple of over priced metal cans on their exhaust pipes with precious metals in them. Call me an ass, idc.

I know what Chris is saying about True duals, with cats and no mufflers. My mom has a 97' with stock manifolds, true duals, 2 new OEM cats running all the way back straight out to 3.5" x 18" stainless Magnaflow tips with the beveled edge. It sounds ******** at idle, AWESOME at WOT, but in moderate driving, in 2nd gear, it makes that aforementioned trash can sound.

The trucks that sound like absolute ****, are the ones with no cats, no mufflers, true duals with the gigantic waste of 3" piping, running to 5" tips.

For example

http://www.youtube.com/watch?v=c_SrsZR8RxE&lc=5BUDbrjsz6x1feAe-ML1v3QcHj2b7NgeImFZlJ5Mgp0&feature=inbox