straight pipe or no?

[shavedaccord]

In theory, yes. In pratice, not as much with our particular vehicles. We just don't have a lot of torque to lose. Butttt, dual exhaust on a 4cyl is about a rice as a bright orange paint job with flame decals

well back to the body shop I go

 

[euroking99]

In theory, yes. In pratice, not as much with our particular vehicles. We just don't have a lot of torque to lose. Butttt, dual exhaust on a 4cyl is about a rice as a bright orange paint job with flame decals

did u forget, the Accord Euro-R came with a dual exhaust and a special H22A7, T2W4 tranny. oh, and that thing looks sick for a stock Accord.

 

[JMillerUA6]

In theory, yes. In pratice, not as much with our particular vehicles. We just don't have a lot of torque to lose. Butttt, dual exhaust on a 4cyl is about a rice as a bright orange paint job with flame decals

I don't know, I think it can be tastefully done. Wildman has a real nice Magnaflow dual setup on his I4. It sounds nice and looks sharp.

 

[xci.ed6]

I thought having the dual muffler setup on the I4 was a bad thing to do. Not enough back pressure for the motor and you would loose torque? But, I could be wrong.... Just add a bigger resonator if you want, or add a second one for it to sound louder..... the stock one alone would probably make it sound the same.....

back pressure does not cause torque, it is a myth.

 

[cronic2geeze]

back pressure does not cause torque, it is a myth.

Wow, I thought that I would never see this tread again. Guess I was wrong. So, the whole back pressure thing is wrong? That's nice to know. So the bigger the pipe, the better performance? Thought that only worked on V-8's.

 

[xci.ed6]

Exhaust gas velocity (egv) helps scavenging, which increases power. Too large of pipe and egv decreases, but there is zero back pressure. Too small of pipe and egv increases, but so does the 'back pressure'.

The scavenging effect relies on having maximum velocity, because it is using the inertia of the column of gas that is flowing out, to create a slight vacuum outside the exhaust valve. Then when the exhaust valve opens the exhaust is basically sucked out of the combustion chamber. The header is primarily responsible for this and the cat-back has very little effect because by the time all 4 cylinders are merged the pipe is large enough that the pressure waves are leveled out.

Now that you know how scavenging works you can see that ANY back pressure is bad, because it opposes the formation of the 'vacuum'. Also, since most of the effect is done after the header, pretty much any free flowing exhaust will be fine. The only thing that WILL hurt performance is a restrictive exhaust system.

So single, duals, even 3" duals, who cares. You're not going to loose torque.

 

[simplesedan99]

i just had a megan racing muffler put on my i4 and had 2 1/2 inch pipe run from the cat all the way back....sounds awsome....i also have megan headers on as well though

 

[pyaarawala]

i just had a megan racing muffler put on my i4 and had 2 1/2 inch pipe run from the cat all the way back....sounds awsome....i also have megan headers on as well though

lol I have pretty much the same thing, except I have a 2.25" pipe with a Magnaflow cat and an Apexi N1 muffler. It does sound very loud but doesn't sound nearly as great as one of the branded catbacks such as WS2 or Evo2. I only have my setup because it was cheap and I couldn't afford a catback back then. For those of you who went to the NE MA meet you know how loud my car is.

 

[Tek_Rice]

Catbacks does not give you more power, at least not noticeable power on our 6th gens. Unless you are running Boost, but then you should be running 3" custom piping and not some after market pre-built system.

TO my experience, I originally had straight pipe from the cat back (no resonator, no pre-muffler) to a set of Magnaflow mufflers and tips. It was so damn loud that, I got a resonator put back on the next day. The droning in cabin was a nightmare.

So if you are thinking about running without a resonator, don't. All aftermarket cat-backs has a resonator for a reason, the fiberglass inside helps eliminate the high frequency drones, which will drive you crazy.

 

[Totalimmortal]

My Megan "test pipe" truly is more of a resonator. It's packed with fiberglass/metal fiber.