Ok I'm a hypocrit!! Speaking of carbon emissions>>
03-06-2008, 11:57 AM
#33
AudiWorld Super User
Join Date: Sep 2001
Location: Censored by IB
Posts: 6,507
Likes: 0
Received 0 Likes
on
0 Posts
Over on RL there is much debate on that
There are two schools of thought... one says there's absolutely no benefit as the n/a motor NEEDS the back-pressure, the other says there is a benefit. At least both sides seem to bring educated info to the table and not just swinging their opinions around.
I know on mine I gutted the cat and *thought* I noticed a difference. I bolted a stock one back on and do feel the difference. On the 944 the gutted cat gives it a tad more oomph off the line and that seems to be about it.
I know on mine I gutted the cat and *thought* I noticed a difference. I bolted a stock one back on and do feel the difference. On the 944 the gutted cat gives it a tad more oomph off the line and that seems to be about it.
03-06-2008, 01:31 PM
#37
AudiWorld Super User
Join Date: Sep 2001
Location: Censored by IB
Posts: 6,507
Likes: 0
Received 0 Likes
on
0 Posts
That was my thought.... but the debate seems to be focused mainly...
on the benefits for the 944 n/a motor.
Going by the butt-dyno, I'd say there is a difference with the gutted cat, at least on mine.
One of the arguments is that a simply gutted cat ends up generating turbulence inside the empty shell that is detrimental. The answer to this is a test pipe.
I CAN say that inside the car it does have more resonance. If you are keeping the car streetable I'd recommend not gutting it. I'm looking at having a shop take my gutted downpipe and replace the cat with a straight pipe.
Going by the butt-dyno, I'd say there is a difference with the gutted cat, at least on mine.
One of the arguments is that a simply gutted cat ends up generating turbulence inside the empty shell that is detrimental. The answer to this is a test pipe.
I CAN say that inside the car it does have more resonance. If you are keeping the car streetable I'd recommend not gutting it. I'm looking at having a shop take my gutted downpipe and replace the cat with a straight pipe.
03-06-2008, 02:32 PM
#38
Member
Join Date: Nov 2006
Posts: 5,031
Likes: 0
Received 0 Likes
on
0 Posts
Obviously mine is not street legal but w/out the cat I think it feels a bit more peppy.
Sure its louder too with no turbo to quiet it down but feels quicker to me. Not sure why some backpressure would be of any benefit for these or any motors.
03-06-2008, 02:40 PM
#39
AudiWorld Super User
Join Date: Sep 2001
Location: Censored by IB
Posts: 6,507
Likes: 0
Received 0 Likes
on
0 Posts
You got me....
I read threads over there till my head was spinning. In the end, when I had the entire exhaust dropped and disassembled during the clutch job, I just said "F it" and gutted mine out.
03-06-2008, 02:42 PM
#40
Member
Join Date: Nov 2006
Posts: 5,031
Likes: 0
Received 0 Likes
on
0 Posts
Mine is gone and just straight pipe to flowmaster race exhaust and the car feels better.
Its what I recommend but think the John Q. Laws would take umbrage at the noise level if for a street legal car.