DP testing, the Ruthless Pursuit of Power
Senior Member
Joined: 05-13-2008
Posts: 2,075
From: Knoxville, TN
Thread Starter
Senior Member
Joined: 04-26-2009
Posts: 669
From: City of Champions
No, just better all around town , throttle response.
It's has something to do with that 1st cat position.
There are 100s of tables in the ECM, that we can't see.
I Believe that the 1st cat is providing just enough back-pressure,
To make the ECM very happy. Resulting in better tip-in throttle response,
& all around better street manners. It least with an automatic.
It just feels so much better, with that 1st cat in place.
It's has something to do with that 1st cat position.
There are 100s of tables in the ECM, that we can't see.
I Believe that the 1st cat is providing just enough back-pressure,
To make the ECM very happy. Resulting in better tip-in throttle response,
& all around better street manners. It least with an automatic.
It just feels so much better, with that 1st cat in place.
Senior Member
Joined: 02-13-2010
Posts: 698
From: HuskerNation
Hmmmm, mine has em on top and bottom....double-you T eff
Senior Member
Joined: 12-20-2011
Posts: 120
From: Cape Cod, MA
Would there be any possible benefit (no loss?) with a 4" custom downpipe? My buddy did a 4" dp on his STI and ran a cutout---- most incredible turbo whistle ive ever heard! I know the k04 isnt a loud whistling turbo but it might make a better noise.
Platinum Member
Joined: 12-06-2009
Posts: 11,721
From: Alabama
Once again I have to correct myself. Yes, mine does have that second double row on the top of the pipe. Found them by sticking a piece of wire up there and "feeling around". I guess the flashlight wasn't hitting them at the right angle.
And as 2005HHRauto said. There is a lot of soot up in the tailpipe.
And as 2005HHRauto said. There is a lot of soot up in the tailpipe.
Senior Member
Joined: 02-13-2010
Posts: 698
From: HuskerNation
Thread Starter
Senior Member
Joined: 04-26-2009
Posts: 669
From: City of Champions
Senior Member
Joined: 09-19-2012
Posts: 70
From: North Glendale, AZ
I think you said somewhere on here that you are using the factory exhaust from the Downpipe back. Did you try any other exhaust systems or mufflers to SEE if they offered a performance gain? I uunderstand that they may offer more noise but, like you, I’m not interested in noise.
I use to work for a major exhaust manufacture and I know that sound does not always mean more power
I am after the best all around performance with the least amount of sound. I've had the loud and now at my age I like um fast and quite. I don't mind a little more sound IF it means some additional power and thanks again for all the great info you are sharing.
I use to work for a major exhaust manufacture and I know that sound does not always mean more power
I am after the best all around performance with the least amount of sound. I've had the loud and now at my age I like um fast and quite. I don't mind a little more sound IF it means some additional power and thanks again for all the great info you are sharing.