Exhaust Questions Answered Here
#1
03-06-2004, 12:32 AM
Exhaust Questions Answered Here
Ok, since there are tons of post every month on what pipe size to use and such I figured I would make a post answering some common questions.
First, Bigger isnt always better. If the pipe is to big it can decrease back pressure to much which will hurt acceleration.
To small of pipe will restrict the exhaust flow more causing the engine to work harder, which also decreeses power, and fuel economy.
Now, fuel economy is what everyone wants. Typically, the bigger the pipe, the more flow which means better economy. But you dont want to big of pipe, as stated above.
Next, performance. Decide where you want your power. At low RPM(for roastin' the tires and beating ricers off the line at a stoplight) or at high RPM(quickly passing someone on the hiway for example). If you want low end power, smaller pipes will produce that, if you want better passing power, or high RPM power, a bigger pie will do that.
Ok, you got that stuff, now your still wondering what size of pipe to use. Well, here is a link to a chart on the Dynomax website that has a recommended size for specific engine sizes.
Dynomax's Pipe Sizing Chart
Now, if you have a modded engine, such as an intake and chip etc, you may want to go bigger. For instance, Dynomax recomends a 2.25 inch diameter pipe for dual exhaust on a say a 4.6 liter engine. If you have a stock engine, this is the most probably the most efficient size, but, if you have soem mods, you may want to go with a 2.5 inch diameter pipe instead, to compensate for the increase in power and air intake from a say a chip and intake system.
Finally, H and X pipes. H-pipes even out the pulses in the exhaust gases and balance the backpressure between both banks of your engine. X pipes do the same. If you find that you want alittle more power from your dual exhasut system, think about having an X pipe installed. It increases backpressure a little bit to increase low RPM power.
Most of the tiem you want to put the H or X pipe as close to exhst manifolds/headers and possible, the best way Ive heard thought is to take some spray paint and paint a strip down the pipes, then take a drive. Where the paint bubbles the most is most likely the place a H or X pipe shole be intalled.
Hopefully this will help some poeple alittle.
Moderators might want to sticky this
First, Bigger isnt always better. If the pipe is to big it can decrease back pressure to much which will hurt acceleration.
To small of pipe will restrict the exhaust flow more causing the engine to work harder, which also decreeses power, and fuel economy.
Now, fuel economy is what everyone wants. Typically, the bigger the pipe, the more flow which means better economy. But you dont want to big of pipe, as stated above.
Next, performance. Decide where you want your power. At low RPM(for roastin' the tires and beating ricers off the line at a stoplight) or at high RPM(quickly passing someone on the hiway for example). If you want low end power, smaller pipes will produce that, if you want better passing power, or high RPM power, a bigger pie will do that.
Ok, you got that stuff, now your still wondering what size of pipe to use. Well, here is a link to a chart on the Dynomax website that has a recommended size for specific engine sizes.
Dynomax's Pipe Sizing Chart
Now, if you have a modded engine, such as an intake and chip etc, you may want to go bigger. For instance, Dynomax recomends a 2.25 inch diameter pipe for dual exhaust on a say a 4.6 liter engine. If you have a stock engine, this is the most probably the most efficient size, but, if you have soem mods, you may want to go with a 2.5 inch diameter pipe instead, to compensate for the increase in power and air intake from a say a chip and intake system.
Finally, H and X pipes. H-pipes even out the pulses in the exhaust gases and balance the backpressure between both banks of your engine. X pipes do the same. If you find that you want alittle more power from your dual exhasut system, think about having an X pipe installed. It increases backpressure a little bit to increase low RPM power.
Most of the tiem you want to put the H or X pipe as close to exhst manifolds/headers and possible, the best way Ive heard thought is to take some spray paint and paint a strip down the pipes, then take a drive. Where the paint bubbles the most is most likely the place a H or X pipe shole be intalled.
Hopefully this will help some poeple alittle.
Moderators might want to sticky this
#2
03-09-2004, 01:00 PM
Senior Member