Header or downpipe?
08-29-07 | 01:18 PM
#26
He who smokes bitches
Joined: Jun 2005
Posts: 3,452
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From: El Dorado County
Downpipe refers to the piece of pipe that runs from the back side of the turbo to the rest of the exhaust. You dont need a downpipe unless your turbocharged.
Since you have an S5 N/A, you need a header. It will make the car louder, and it will be quite loud with the Apexi GT spec. It'll sound pretty good, but will be loud unless you have a resonator or two, and a cat still in place.
Since you have an S5 N/A, you need a header. It will make the car louder, and it will be quite loud with the Apexi GT spec. It'll sound pretty good, but will be loud unless you have a resonator or two, and a cat still in place.
Good luck with the downpipe laserkei. I made the mistake of getting a header. Not only is the downpipe a lot less of a pain in the *** to install, but is also quieter with similar power gains.
08-29-07 | 03:41 PM
#27
Thread Starter
How about a cup of RAGE
iTrader: (3)
Joined: Sep 2006
Posts: 416
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From: Orange County
And you don't need to be answering questions when you don't know the answer.
Good luck with the downpipe laserkei. I made the mistake of getting a header. Not only is the downpipe a lot less of a pain in the *** to install, but is also quieter with similar power gains.
Good luck with the downpipe laserkei. I made the mistake of getting a header. Not only is the downpipe a lot less of a pain in the *** to install, but is also quieter with similar power gains.
08-31-07 | 12:33 AM
#30
Uh....if you have the cat, you'll probably still want your air pump. If you have an S5 and are running stock ECU, you definitely need the airpump for your 6PI and your VDI.
08-31-07 | 09:17 AM
#32
Um...the GT doesn't have a pre-silencer, does it? That's why it's call a cat-back, from the catalytic convertor back. The presilencer replaces the cat and thus, would not be part of a cat-back exhaust.
Now if you had an engine-back exhaust, that would entail headers, pre-silencer and cat-back.
Now if you had an engine-back exhaust, that would entail headers, pre-silencer and cat-back.
08-31-07 | 11:52 AM
#33
Thread Starter
How about a cup of RAGE
iTrader: (3)
Joined: Sep 2006
Posts: 416
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From: Orange County
Um...the GT doesn't have a pre-silencer, does it? That's why it's call a cat-back, from the catalytic convertor back. The presilencer replaces the cat and thus, would not be part of a cat-back exhaust.
Now if you had an engine-back exhaust, that would entail headers, pre-silencer and cat-back.
Now if you had an engine-back exhaust, that would entail headers, pre-silencer and cat-back.
08-31-07 | 12:22 PM
#36
S4 needs to keep airpump for aux activation.
If you are running a cat you need the air pump or you will burn it out.
08-31-07 | 12:24 PM
#37
My car's previous owner ran a dummy cat instead. You could try finding a way to bolt the outside metal covers of the cat around your pre-silencer for it to fool visual. As for smog, look for J-rat's recipe for cheating emissions only if it's absolutely necessary. Alternatively, you can always buy a cat and bolt it on solely for emissions checks. My tuner also told me you don't need to blockoff the split air tube, though i would do it anyway, i'm just looking for a block-off plate. FWIW, my split air tube that goes to the cat is pinched.
S4 is exhaust backpressure activation for 6PI. S4's do not have VDI.
electronic (on both S4 and S5) is an modification that you have to perform yourself. So is airpump activation on S4.
S5 is air pump activation on both VDI and 6PI.
electronic (on both S4 and S5) is an modification that you have to perform yourself. So is airpump activation on S4.
S5 is air pump activation on both VDI and 6PI.
08-31-07 | 01:41 PM
#38
Thread Starter
How about a cup of RAGE
iTrader: (3)
Joined: Sep 2006
Posts: 416
Likes: 0
From: Orange County
My car's previous owner ran a dummy cat instead. You could try finding a way to bolt the outside metal covers of the cat around your pre-silencer for it to fool visual. As for smog, look for J-rat's recipe for cheating emissions only if it's absolutely necessary. Alternatively, you can always buy a cat and bolt it on solely for emissions checks. My tuner also told me you don't need to blockoff the split air tube, though i would do it anyway, i'm just looking for a block-off plate. FWIW, my split air tube that goes to the cat is pinched.
S4 is exhaust backpressure activation for 6PI. S4's do not have VDI.
electronic (on both S4 and S5) is an modification that you have to perform yourself. So is airpump activation on S4.
S5 is air pump activation on both VDI and 6PI.
S4 is exhaust backpressure activation for 6PI. S4's do not have VDI.
electronic (on both S4 and S5) is an modification that you have to perform yourself. So is airpump activation on S4.
S5 is air pump activation on both VDI and 6PI.
08-31-07 | 01:57 PM
#39
Ah, thats where I was confused. Airpump vs Exhaust.
