3 inch or 2.5 inch exhaust?
08-12-2006, 02:13 AM
#1
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3 inch or 2.5 inch exhaust?
anyone know what the real difference is between these to. ive heard the 3 inch has a deeper sound... but im still unsure.
to add if they are good... anyone know where u can get a nice full exhaust system for a 03gt that is 3inch?
to add if they are good... anyone know where u can get a nice full exhaust system for a 03gt that is 3inch?
08-12-2006, 02:25 AM
#2
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RE: 3 inch or 2.5 inch exhaust?
what do you mean? catback or complete?
I honestly wouldn't reccomend doing it complete 3". If you do, you will probably lose horsepower because the place where 3" exhaust shines is high horsepower N/A and nitrous/supercharger applications.
I honestly wouldn't reccomend doing it complete 3". If you do, you will probably lose horsepower because the place where 3" exhaust shines is high horsepower N/A and nitrous/supercharger applications.
08-12-2006, 02:51 AM
#4
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RE: 3 inch or 2.5 inch exhaust?
ORIGINAL: monkeydude3
what do you mean? catback or complete?
I honestly wouldn't reccomend doing it complete 3". If you do, you will probably lose horsepower because the place where 3" exhaust shines is high horsepower N/A and nitrous/supercharger applications.
what do you mean? catback or complete?
I honestly wouldn't reccomend doing it complete 3". If you do, you will probably lose horsepower because the place where 3" exhaust shines is high horsepower N/A and nitrous/supercharger applications.
08-12-2006, 03:19 AM
#6
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Join Date: Mar 2006
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RE: 3 inch or 2.5 inch exhaust?
The reason it may seem like you go slower with 3" exhaust compared to 2-1/2" is because you will lose back pressure, something the motor depends on. When I put headers on my old car a 65 El Camino 327 I didn't have exhaust and had to run it to a shop about 50 or so miles away for a complete exhaust system. I thought about 3" for that 327 but a speed shop mechanic told me that with a motor displacing even 327c.i. it wouldn't be wise to do so because the power you gain will be way up in the rpms. 2-1/4" is what they suggested for my little 327 so I would venture to say that even 2-1/2" is good enough for our 281c.i.'s. Backpressure will give you better low end torque and your hp increases will still be within your powerband. So if your plans are like everyone else said, to s/c or put a shot of juice on it then 2-1/2" should be all you need...plus i could see with 3" a decrease in mpg...Instead of 2-1/2 you could consider 2-1/4"
Could be wrong but my .02
Could be wrong but my .02
08-12-2006, 03:31 AM
#7
6th Gear Member
Join Date: May 2006
Location: Ohio
Posts: 6,448
RE: 3 inch or 2.5 inch exhaust?
Sorry Black98GT but you are alittle off. You do not need back pressure.
Most of the time bigger is better, but that's not always the case with exhaust. Today's late model cars are designed with several restrictions on the manufacturers. So in order to perform but still stay within the limits of emissions and other regulations, the exhaust is usually the first thing to suffer from the factory. The easy power that is found in changing the original equipment exhaust system, is just one of the many reasons there are so many aftermarket manufacturers capitalizing on this insufficiency. But just opening the exhaust doesn't always make more power, it takes the correct combination of flow capability and velocity. That's why performance exhaust manufacturers spend so much time in search of just the right combination, so that they can ensure peak power to their customers.
In this article we will discuss the effects that exhaust backpressure has on your engine. Backpressure is the restriction of the exhaust gases that are produced by your engine while they are being released through your exhaust system. Exhaust gasses are the burned and unburned gasses that are released out of the exhaust system after engine combustion happens.
The exhaust system should have minimal restriction to the exhaust flow that is being released in order to create the most amount of power from the engine. With restriction present, backpressure is developed, making the engine work much harder to release the exhaust out of the engine cylinders.
The standard for exhaust diameter is to not run too large of exhaust, for the engine needs a certain amount of backpressure. This is correct in the sense of one should not run too large of diameter exhaust tubing, but the statement of the engine needing backpressure is not. You need to have the least amount of backpressure possible to produce maximum power. Too large of diameter exhaust will cause a power loss and loss of low end torque because a larger pipe has less exhaust stream velocity than a smaller pipe. If the exhaust pipe is too large, then the exhaust flow will be slowed with less velocity. There are exceptions, forced induction or high-volume race engines require a larger diameter exhaust due to the flow characteristics of the engine. Supercharged and turbocharged vehicles can have an exhaust gas volume of 1 to 2 times more than an equivalent displacement naturally aspirated engine. In this case, one is able to use a larger diameter of exhaust for greater performance.
This was taken from https://mustangforums.com/m_1789889/tm.htm
This has been a big argument for along time and I'm glad this guy posted it cause I could never find hard evidence before.
Most of the time bigger is better, but that's not always the case with exhaust. Today's late model cars are designed with several restrictions on the manufacturers. So in order to perform but still stay within the limits of emissions and other regulations, the exhaust is usually the first thing to suffer from the factory. The easy power that is found in changing the original equipment exhaust system, is just one of the many reasons there are so many aftermarket manufacturers capitalizing on this insufficiency. But just opening the exhaust doesn't always make more power, it takes the correct combination of flow capability and velocity. That's why performance exhaust manufacturers spend so much time in search of just the right combination, so that they can ensure peak power to their customers.
In this article we will discuss the effects that exhaust backpressure has on your engine. Backpressure is the restriction of the exhaust gases that are produced by your engine while they are being released through your exhaust system. Exhaust gasses are the burned and unburned gasses that are released out of the exhaust system after engine combustion happens.
The exhaust system should have minimal restriction to the exhaust flow that is being released in order to create the most amount of power from the engine. With restriction present, backpressure is developed, making the engine work much harder to release the exhaust out of the engine cylinders.
The standard for exhaust diameter is to not run too large of exhaust, for the engine needs a certain amount of backpressure. This is correct in the sense of one should not run too large of diameter exhaust tubing, but the statement of the engine needing backpressure is not. You need to have the least amount of backpressure possible to produce maximum power. Too large of diameter exhaust will cause a power loss and loss of low end torque because a larger pipe has less exhaust stream velocity than a smaller pipe. If the exhaust pipe is too large, then the exhaust flow will be slowed with less velocity. There are exceptions, forced induction or high-volume race engines require a larger diameter exhaust due to the flow characteristics of the engine. Supercharged and turbocharged vehicles can have an exhaust gas volume of 1 to 2 times more than an equivalent displacement naturally aspirated engine. In this case, one is able to use a larger diameter of exhaust for greater performance.
This was taken from https://mustangforums.com/m_1789889/tm.htm
This has been a big argument for along time and I'm glad this guy posted it cause I could never find hard evidence before.
08-12-2006, 03:48 AM
#10
5th Gear Member
Join Date: Mar 2005
Location: Nashville/Knoxville, Tennessee
Posts: 4,687
RE: 3 inch or 2.5 inch exhaust?
ORIGINAL: oxfordgt
Sorry Black98GT but you are alittle off. You do not need back pressure.
Most of the time bigger is better, but that's not always the case with exhaust. Today's late model cars are designed with several restrictions on the manufacturers. So in order to perform but still stay within the limits of emissions and other regulations, the exhaust is usually the first thing to suffer from the factory. The easy power that is found in changing the original equipment exhaust system, is just one of the many reasons there are so many aftermarket manufacturers capitalizing on this insufficiency. But just opening the exhaust doesn't always make more power, it takes the correct combination of flow capability and velocity. That's why performance exhaust manufacturers spend so much time in search of just the right combination, so that they can ensure peak power to their customers.
In this article we will discuss the effects that exhaust backpressure has on your engine. Backpressure is the restriction of the exhaust gases that are produced by your engine while they are being released through your exhaust system. Exhaust gasses are the burned and unburned gasses that are released out of the exhaust system after engine combustion happens.
The exhaust system should have minimal restriction to the exhaust flow that is being released in order to create the most amount of power from the engine. With restriction present, backpressure is developed, making the engine work much harder to release the exhaust out of the engine cylinders.
The standard for exhaust diameter is to not run too large of exhaust, for the engine needs a certain amount of backpressure. This is correct in the sense of one should not run too large of diameter exhaust tubing, but the statement of the engine needing backpressure is not. You need to have the least amount of backpressure possible to produce maximum power. Too large of diameter exhaust will cause a power loss and loss of low end torque because a larger pipe has less exhaust stream velocity than a smaller pipe. If the exhaust pipe is too large, then the exhaust flow will be slowed with less velocity. There are exceptions, forced induction or high-volume race engines require a larger diameter exhaust due to the flow characteristics of the engine. Supercharged and turbocharged vehicles can have an exhaust gas volume of 1 to 2 times more than an equivalent displacement naturally aspirated engine. In this case, one is able to use a larger diameter of exhaust for greater performance.
This was taken from https://mustangforums.com/m_1789889/tm.htm
This has been a big argument for along time and I'm glad this guy posted it cause I could never find hard evidence before.
Sorry Black98GT but you are alittle off. You do not need back pressure.
Most of the time bigger is better, but that's not always the case with exhaust. Today's late model cars are designed with several restrictions on the manufacturers. So in order to perform but still stay within the limits of emissions and other regulations, the exhaust is usually the first thing to suffer from the factory. The easy power that is found in changing the original equipment exhaust system, is just one of the many reasons there are so many aftermarket manufacturers capitalizing on this insufficiency. But just opening the exhaust doesn't always make more power, it takes the correct combination of flow capability and velocity. That's why performance exhaust manufacturers spend so much time in search of just the right combination, so that they can ensure peak power to their customers.
In this article we will discuss the effects that exhaust backpressure has on your engine. Backpressure is the restriction of the exhaust gases that are produced by your engine while they are being released through your exhaust system. Exhaust gasses are the burned and unburned gasses that are released out of the exhaust system after engine combustion happens.
The exhaust system should have minimal restriction to the exhaust flow that is being released in order to create the most amount of power from the engine. With restriction present, backpressure is developed, making the engine work much harder to release the exhaust out of the engine cylinders.
The standard for exhaust diameter is to not run too large of exhaust, for the engine needs a certain amount of backpressure. This is correct in the sense of one should not run too large of diameter exhaust tubing, but the statement of the engine needing backpressure is not. You need to have the least amount of backpressure possible to produce maximum power. Too large of diameter exhaust will cause a power loss and loss of low end torque because a larger pipe has less exhaust stream velocity than a smaller pipe. If the exhaust pipe is too large, then the exhaust flow will be slowed with less velocity. There are exceptions, forced induction or high-volume race engines require a larger diameter exhaust due to the flow characteristics of the engine. Supercharged and turbocharged vehicles can have an exhaust gas volume of 1 to 2 times more than an equivalent displacement naturally aspirated engine. In this case, one is able to use a larger diameter of exhaust for greater performance.
This was taken from https://mustangforums.com/m_1789889/tm.htm
This has been a big argument for along time and I'm glad this guy posted it cause I could never find hard evidence before.