Exhaust Theory

[nickers]

not to mention most cars need their computers to be tuned to allow for performance increases, doing upgrades without doing so can rob you of performance.

back pressure is not need in a turbo system... back pressure causes resistance on the turbo affecting how it spools, therefore less backpressure greater spooling allowing it to properly increase your volumetric efficiency of your engine.

now based on my knowledge i could point out that there is valve overlap in between the exhaust stroke and intake stroke, the exhaust valve is smaller in diameter which causes the exhaust gases to be pushed out at a higher velocity, this low pressure created by the exhaust gases leaving causes a vacuum effect on intake air sucking it in. with reduced back pressure a greater quantity of air to be drawn into the combustion chamber causing your car to run leaner, which in turn causes performance issues.

youve been mechanic'd

[armykyle1]

not to mention most cars need their computers to be tuned to allow for performance increases, doing upgrades without doing so can rob you of performance.

back pressure is not need in a turbo system... back pressure causes resistance on the turbo affecting how it spools, therefore less backpressure greater spooling allowing it to properly increase your volumetric efficiency of your engine.

now based on my knowledge i could point out that there is valve overlap in between the exhaust stroke and intake stroke, the exhaust valve is smaller in diameter which causes the exhaust gases to be pushed out at a higher velocity, this low pressure created by the exhaust gases leaving causes a vacuum effect on intake air sucking it in. with reduced back pressure a greater quantity of air to be drawn into the combustion chamber causing your car to run leaner, which in turn causes performance issues.

youve been mechanic'd

.... I believe one of the common terms is "over spooling" basically the turbo continues to spin faster and longer than it should, with drop in RPMs less oil is pumped through the turbo(depending on the oiling system of course) yes it takes the turbo the extra little bit of time to slow down. Not a huge issue, but an issue none the less. I've seen this to be more of an issue with HD trucks though.

[95legwagon]

*this should be stickied*

great write up.

found out about the muffler the hard way. went from stock 2 1/2 pipe to 3 1/2 id inlet and 4" id out. it was too loud and lost bottom end because of no tune..... it sounded the same as running with no muffler. LOL

needless to say i put a different muffler on it with a lil bit smaller diameters..... its like 2 3/4 id inlet and 3 " out. does way better than before and also quieter ha

-jarrid