No Muffler
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CF Junior Member
Joined: Mar 2007
Posts: 70
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No Muffler
I just bought a 2008 Silverado with what was passed off as a "radical" exhaust. Come to find out they eliminated the muffler entirely. It sounds great but can this lack of backpressure damage the engine or effect mileage? No service engine light....
Administrator
Joined: Apr 2008
Posts: 7,573
Likes: 47
From: Austin, Texas
I think most of the back pressure comes from the cat thou I am sure the muffler provides some. I know the flowmaster have 3 to 5 chambers and from what I have seen of them they don't provide a lot of BP, I would be more concerned about the excessive noise or drone no muffler would produce not to mention a possible ticket for excessive loudness....
CF Senior Member
Joined: Nov 2010
Posts: 367
Likes: 1
No muffler
I wouldn't worry about lack of backpressure. Too much will do more harm than not enough. With the older carb engines this was more important, with the fuel injected ones the system will compensate for it.
CF Senior Member
Joined: Mar 2010
Posts: 547
Likes: 6
From: Redding, California
I have cored out pipes on my bike. A 2.5 inch corrigated pipe with no cats.
The pipes alone offer plenty of backpressure.
I would put an exhaust on if I were you, put on a flowmaster 10 series if you want it loud with 3" pipes.
But to each their own.
The pipes alone offer plenty of backpressure.
I would put an exhaust on if I were you, put on a flowmaster 10 series if you want it loud with 3" pipes.
But to each their own.
CF Beginner
Joined: Dec 2010
Posts: 12
Likes: 0
Backpressure is bad. Period.
Backpressure is resistance, it robs your engine of power. It's a common misconception that a certain amount of backpressure is needed. Really, backpressure is an absolute evil, exhaust velocity is what you want. Velocity comes from a properly sized and shaped exhaust system. People would put 4" dual exhaust on their truck, thinking 'bigger is better', and when this performed poorly, they blamed it on 'lack of backpressure'. Wrong, it's a lack of velocity. Think of this. You are drinking a soda, and you have a choice of 3 straws. A tiny coffee stirrer sized straw, an average sized straw, or a huge inch wide straw. Which is going to get you more liquid? The average sized straw will, it will create the best velocity. The small one will be restricted because of it's small size. (I.E. backpressure) The big one won't flow properly because it's to wide. (I.E. lack of velocity).
http://www.miata.net/garage/KnowYourCar/S4_Back.html If you want to read a little more.
Running without a muffler will decrease backpressure, but will not hurt velocity (as long as your exhaust isn't cutoff at the cab or anything crazy like that)... Theoretically, this could even perform better than stock. That being said, it's going to sound like ****, be way to loud, hurt your ears, annoy your neighbors, **** off the car behind you at the stop light, possibly get you flipped off on occasion and probably get you a 'redneck' or 'ricer' label. Not to mention, most likely illegal in your area.
Backpressure is resistance, it robs your engine of power. It's a common misconception that a certain amount of backpressure is needed. Really, backpressure is an absolute evil, exhaust velocity is what you want. Velocity comes from a properly sized and shaped exhaust system. People would put 4" dual exhaust on their truck, thinking 'bigger is better', and when this performed poorly, they blamed it on 'lack of backpressure'. Wrong, it's a lack of velocity. Think of this. You are drinking a soda, and you have a choice of 3 straws. A tiny coffee stirrer sized straw, an average sized straw, or a huge inch wide straw. Which is going to get you more liquid? The average sized straw will, it will create the best velocity. The small one will be restricted because of it's small size. (I.E. backpressure) The big one won't flow properly because it's to wide. (I.E. lack of velocity).
http://www.miata.net/garage/KnowYourCar/S4_Back.html If you want to read a little more.
Running without a muffler will decrease backpressure, but will not hurt velocity (as long as your exhaust isn't cutoff at the cab or anything crazy like that)... Theoretically, this could even perform better than stock. That being said, it's going to sound like ****, be way to loud, hurt your ears, annoy your neighbors, **** off the car behind you at the stop light, possibly get you flipped off on occasion and probably get you a 'redneck' or 'ricer' label. Not to mention, most likely illegal in your area.
Last edited by Bill Miller; Dec 16, 2010 at 10:12 PM.
