I just had a CherryBomb Glasspack muffler put on my Blazer replacing the stock muffler. What a waste of 30 bucks for the muffler, and 60 to have it put on. I'm ready to rip it off myself and have no muffler at all.

Makes no difference if it's on or just a straight pipe. Wouldn't recommend. Better off investing in something decent like the Flowmaster 40.

 

I have a cherrybomb glasspack on my 86 it sounds great and pops real loud when im in stop and go and my engine is only a 2.8 lol

ps i get 23.6 mpg

 

I don't want to offend you, but you should pick up a book or two and learn how an internal combustion engine works instead of leading people astray with erroneous statements such as the one above. Back pressure is very real.

Sorry, but that's just not true. There is a ton of information available from various manufacturers and magazine reviews that show significant gains in hp, torque and mpg by doing nothing more than installing an aftermarket cat-back exhaust system. Yes, you will see a higher gain if you also install headers, but an increase of 8-10 hp, 12-15 lb-ft of torque and a 1-2 mpg increase are realistic and has been proven over and over again on the dyno. Sure, maybe if you just pick a muffler because of the way it sounds and slap it on in place of the stock one you may not see a difference, but if you install a properly designed cat-back system it's quite possible to see the increases mentioned above. If you think what I'm saying is incorrect then I suggest you do some independant research rather than basing your opinion on hear-say. Again, I'm not trying to offend you, but if you had done the research previously you would know the truth and wouldn't have made the statements you did.

 

Read the last line of my last post...

 

Backpressure is a myth and its bad for your motor. You want exhaust velocity and a proper built exhaust will have the right scavenging affect. Backpressure is pressure being sent back to the motor from some sort of restriction in your exhaust and not letting it flow.

I think Benedict was talking about having 3" Pipes is too larger for a stock Blazer. 2.5" works fine and for True dual you can run 2" or 2.25" Straight pipes if you wanted and make killer low end and mid end.

http://www.superchevy.com/technical/...exh/index.html
A motor never needs backpressure when theres results that show that no restriction is what wanted and nothing but solid flow, and how the size of the pipes affect where the power band is and the rpms the engine can function more effectively http://www.pontiacstreetperformance....p/exhaust.html

 

Your statements contradict one another. When the piston rises in the cylinder after the combustion stroke it attempts to evacuate the residual gases from the cylinder. Those gases create back pressure on the piston. Also, when the gases enter the exhaust manifold they collide with gases from the previous cylinder's exhaust cycle. A portion of the gases reverse path and travel back towards the cylinder creating more back pressure. The whole idea of improving the scavenging effect and reducing restrictions in the exhaust system is to reduce back pressure. If back pressure is a myth (not real) then why do manufacturers do so much R&D to develop exhaust manifolds and headers to improve cylinder scavenging? Why is it that the main goal of a performance exhaust is to reduce restriction? The answer: To reduce back pressure.

But that's not what he said:

'the only way of loosing or gaining power in an exhaust system is if you replace everything, headers, high flow cat, performance exhaust 3" pipes the whole way back. without that there is no gains or looses that are noticeable'

Quote:

Originally Posted by PaulO2288

A motor never needs backpressure when theres results that show that no restriction is what wanted and nothing but solid flow, and how the size of the pipes affect where the power band is and the rpms the engine can function more effectively

I agree - you want to reduce back pressure and restriction in the exhaust system to improve efficiency. Your statement validates what I have been saying all along. Back pressure is real - not a myth.

 

You took it the wrong way. When its said that backpressure is a myth its a myth that its not needed! Your truck/car will make the most power with straight pipes with the appropriate size piping depending on your rpm range that your engine runs in and if its naturally aspirated or has some sort of forced induction then requiring larger piping to accommodate the more gases being produced from the motor.

Did you at all look at those links posted? I can find so many more to show you that backpressure is bad, not needed at all to make power, and its exhaust scavenging thats needed

 

Don't forget too, a hot exhaust flows more than a cold exhaust...

 

Your right and having the right sizes pipes keeps is about 90% of that imo

 

I agree...

...In my opinion, any aftermarket muffler sounds like **** on a 4.3! I don't care if you have a single $100 Flowmaster, or 6 separate pipes from each cylinder with 6 different mufflers attached to all pipes, they all sound like butt... (I have to admit, I have never seen or heard that setup, so I may be incorrect,) but I am assuming it too, would sound like buttocks.