pantha
Registered User
So let me set the scene.
I have an A3 8P 2.0tfsi Quattro.
I also have (Sitting in the shed) a 3" APR Stainless DP with flex attached.
I want to have a custom exhaust installed, (Personal reasons) and here is what I'm thinking:
I install the 3" DP, into a 3" Cat, then shift/taper to a 2.5" catback system with hi-flow 2.5" mufflers. I like the brand Magnaflow as they have a good reputation and they pride themselves on a good throaty sound.
Note: I read that the majority of the power "gains" comes from the DP, and the Cat-back is purely a sound thing??? (Larger diam = louder)
My understanding of Physics is, when a fluid (Yes, air is a fluid) flows through a pipe, if the pipe increases in diameter, the pressure increases with it, at a cost of velocity. And complimentary to that, if the diameter of the pipe decreases, the pressure will drop, and velocity will increase.
SO....
Should I keep the 3" DP, and have a 3" cat as previously stated, to have "Pressure" from the Turbo outlet into the DP, to overcome flow restriction from the Cat... then, once past the cat, reduce the diameter, to aid in velocity of the gases. Not to mention that, by then, the gases would have significantly cooled, and would not require such a larger diameter to accommodate them.
Am I thinking clearly... OR ... Should I switch out the 3" DP for a 2.75" DP? (And if I did, what size Cat?)
Cheers!
I have an A3 8P 2.0tfsi Quattro.
I also have (Sitting in the shed) a 3" APR Stainless DP with flex attached.
I want to have a custom exhaust installed, (Personal reasons) and here is what I'm thinking:
I install the 3" DP, into a 3" Cat, then shift/taper to a 2.5" catback system with hi-flow 2.5" mufflers. I like the brand Magnaflow as they have a good reputation and they pride themselves on a good throaty sound.
Note: I read that the majority of the power "gains" comes from the DP, and the Cat-back is purely a sound thing??? (Larger diam = louder)
My understanding of Physics is, when a fluid (Yes, air is a fluid) flows through a pipe, if the pipe increases in diameter, the pressure increases with it, at a cost of velocity. And complimentary to that, if the diameter of the pipe decreases, the pressure will drop, and velocity will increase.
SO....
Should I keep the 3" DP, and have a 3" cat as previously stated, to have "Pressure" from the Turbo outlet into the DP, to overcome flow restriction from the Cat... then, once past the cat, reduce the diameter, to aid in velocity of the gases. Not to mention that, by then, the gases would have significantly cooled, and would not require such a larger diameter to accommodate them.
Am I thinking clearly... OR ... Should I switch out the 3" DP for a 2.75" DP? (And if I did, what size Cat?)
Cheers!