Exuast or no exuast, that is the question

[Slo98SS]

hey guys, yeah that was gay but it got ur attention, but here is my idea


Take off my cat back and just run a straight pipe off of hte stock Y

or

Get a cut out and leave everything

or

get rid of the cat back, and have a bullet welded onto my existing y pipe.


I wanna be loud on the cheap. I cant stand my gay stock single outlet 1998 SS exuast, plus it rattles like no other so there is one reason to "fix". Lemme know what you guys think. I am doing this cheap cuz i am gonna go headers by Christmas.

[WishIHadACamaro]

Cut every piece of restriction you have under your car, im going to with my resto.

Headers and piping. And only pipes because i dont want exhaust dumping into my passenger compartment.

[Slo98SS]

iight, well i think im gonna rip out my cat back and see how it goes. then a bullet is gonna be added if i dont like it

[kalel]

Originally Posted by Slo98SS

iight, well i think im gonna rip out my cat back and see how it goes. then a bullet is gonna be added if i dont like it

I've got bullets and I love them. Can't beat the sound for the price. It will be loud too. They are good about reducing rasp. :smt023

[ta12sec]

eric slpls1 is out reident exhaust guru ask him what he thinks


:smt045

[contraststriker]

zero backpressure isn't nice to stock valvetrain components...

[Ta Jay]

Originally Posted by ta12sec

eric slpls1 is out reident exhaust guru ask him what he thinks


:smt045

:smt045

[Admin]

Originally Posted by ta12sec

eric slpls1 is out reident exhaust guru ask him what he thinks


:smt045

Brad! Brad! Brad! :h

Well guys, I ended up going with bullets and Kooks headers! We will see how they feel. Just having headers on felt like you lost back pressure, but when I think you get a tune and a catback on it will make a lot of difference. A lot more backpressure will be there!!! This is a big question among forums. I think Contrastriker is right, you have to have something on back of there(Headers) for stock valvetrain. Everything has to work with your type of setup.

If I were you Slo98SS I'd end up running dumps with your headers! Texas Speed has a setup like that which is pritty cheap. If you run just headers with stock valvetrain, the power isn't going to be there(low end). Though, maybe with a good tune I could be wrong.

[ta12sec]

to save me some typing I found an article for you guys

No. It would be more correct to say, "a perfectly stock engine that cannot adjust its fuel delivery needs backpressure to work correctly." This idea is a myth. As with all myths, however, there is a hint of fact with this one. Particularly, some people equate backpressure with torque, and others fear that too little backpressure will lead to valve burning.

The first reason why people say "backpressure is good" is because they believe that increased backpressure by itself will increase torque, particularly with a stock exhaust manifold. Granted, some stock manifolds act somewhat like performance headers at low RPM, but these manifolds will exhibit poor performance at higher RPM. This, however does not automatically lead to the conclusion that backpressure produces more torque. The increase in torque is not due to backpressure, but to the effects of changes in fuel/air mixture, which will be described in more detail below.

The other reason why people say "backpressure is good" is because they hear that cars (or motorcycles) that have had performance exhaust work done to them would then go on to burn exhaust valves. Now, it is true that such valve burning has occurred as a result of the exhaust mods, but it isn't due merely to a lack of backpressure.

The internal combustion engine is a complex, dynamic collection of different systems working together to convert the stored power in gasoline into mechanical energy to push a car down the road. Anytime one of these systems are modified, that mod will also indirectly affect the other systems, as well.

Now, valve burning occurs as a result of a very lean-burning engine. In order to achieve a theoretical optimal combustion, an engine needs 14.7 parts of oxygen by mass to 1 part of gasoline (again, by mass). This is referred to as a stochiometric (chemically correct) mixture, and is commonly referred to as a 14.7:1 mix. If an engine burns with less oxygen present (13:1, 12:1, etc...), it is said to run rich. Conversely, if the engine runs with more oxygen present (16:1, 17:1, etc...), it is said to run lean. Today's engines are designed to run at 14.7:1 for normally cruising, with rich mixtures on acceleration or warm-up, and lean mixtures while decelerating.

Getting back to the discussion, the reason that exhaust valves burn is because the engine is burning lean. Normal engines will tolerate lean burning for a little bit, but not for sustained periods of time. The reason why the engine is burning lean to begin with is that the reduction in backpressure is causing more air to be drawn into the combustion chamber than before. Earlier cars (and motorcycles) with carburetion often could not adjust because of the way that backpressure caused air to flow backwards through the carburetor after the air already got loaded down with fuel, and caused the air to receive a second load of fuel. While a bad design, it was nonetheless used in a lot of vehicles. Once these vehicles received performance mods that reduced backpressure, they no longer had that double-loading effect, and then tended to burn valves because of the resulting over-lean condition. This, incidentally, also provides a basis for the "torque increase" seen if backpressure is maintained. As the fuel/air mixture becomes leaner, the resultant combustion will produce progressively less and less of the force needed to produce torque.

Modern cars don't have to worry about the effects described above, because the ecm (car's computer) that controls the engine will detect that the engine is burning leaner than before, and will adjust fuel injection to compensate. So, in effect, reducing backpressure really does two good things: The engine can use work otherwise spent pushing exhaust gas out the tailpipe to propel the car forward, and the engine breathes better. Of course, the ecm ability to adjust fuel injection is limited by the physical parameters of the injection system (such as injector maximum flow rate and fuel system pressure), but with exhaust backpressure reduction, these limits won't be reached.

[Admin]

Time to take a breath Brad! :)lol

I deffinately learned something there, I just hope most of it is right :-)