The whole idea with aftermarket exhausts or no exhaust is to free up the flow, which in some cases can improve power. But that's the balance. Your car may or may not need so much backpressure. In some cases loss of back pressure can cause loss of top end.

Straight exhaust really serves not a lot of purpose unless you know that your car is running MUCH better without it because you've done some kind of crazy mods or something like that; but even then it would be hard to justify straight exhaust unless you knew it was doing the engine way better (most likely it's not).

Speaking to the noise... Well, yes, obviously cars are going to be WAY louder without any exhaust; plus as far as I know, you have to have a cat. and muffler to pass emmissions.

Back to the noise thing... 4 cyl can be noisy w/o mufflers but come on, it's an Accord 4 cyl. It's not going to be like a NASCAR V8. My buddy runs no muffler on his WRX wagon in Solo II and it actually sounds great and not that loud (still under allowable/rebulation dbs).

Best advise... Get a muffler.

HTH.

 

Thats not his car in the avatar
http://www.cardomain.com/memberpage/526094

It belongs to someone in GA

 

From what I know, I thought the loss of back pressure will result in the loss of bottom end, not top end. You will actually gain top end from not having backpressure. Someone correct me if I'm wrong. The backpressure is basically just something crucial to engines with low HP (I4 accords for example) A V8, or a turbo car will not really see a difference with or without backpressure.



PS. just get a damn muffler

 

haha i hate when people do that

 

Yes, JL... You are correct, sir. I apologize. I was too busy typing to pay attention. Yes, a loss in back pressure can affect (take away) your LOW end.

There are a lot of myths around back pressue. This is where headers and acoustical signatures and all that fun stuff can come in to play too...

Sorry.

Yeah, get a muffler.

 

actually back pressure doesn't cause pressure loss...it just so happens that under the same conditions that u lose back pressure, u lose low end power...but the loss of back pressure isn't what's causing it. they just happen to both be side effects of open exhaust that occur at the same time, but they dont cause each other.

 

i got a magnaflow muffler welded on today, sounds pretty nice, close to stock sounding at idle and crusing on highway.

 

So then what does increasing or decreasing back pressure affect? Why do some cars need more or less?

 

it affects nothing... what i thought all along....

backpressure is a myth

 

It's also a misunderstanding.

Lower instantaneous pressure is better for scavenging. Problem is, most people think about the exhaust sytem as if it was steady-state flow. Really, the flow pulsates, and each pulse is reflected back thru the manifold to other cylinders. That either helps or hurts exhaust scavenging.

So you want a system where those pulses are coordinated to help out the other cylinders. That's often a system which has more 'restriction' if you simply test it by flowing steady-state. It takes either more sophisticated analysis or instrumentation to show that it really does result in lower exhaust pressure at the right moment in the cycle.