I'm looking for some first hand real world info on the SLP Y-Pipe and hand-held programers that are available. I have a Stock 02 A4 SS with the 345 HP option. Is there any real "performance advantage" to installing the SLP Y-Pipe and/or replacing the muffler-exhaust system on this car? I am not interested in headers or a louder exhaust system, but only true performance gains, it must also remain emission legal. Also, with the A4 in my SS, is there any "performance advantange" in adding the tuning of a power programer to this car? I did a search, but I would really appreciate some first hand knowledge from persons who have these items on their car and their experience with them. If you can help an old 50 year old car nut out it would be great, thanks.

 

The hypertech is a good one if you have the A4. You will be able to firm up the shifts. You will feel the diffrencs. I have they dynomouth exhaust, its loud but i got some good gains from it. Ablout .2 1/4 mile

 

I never have had my car dynoed but I have slp loudmouth with the slp y-pipe and I love the sound. I can tell that I picked up a little performance as well, but I also have a couple other things done. My girlfriend has a 99Z with just the loudmouth and no slp y-pipe and my car is just slightly louder at an idle. As far as being louder while accellerating though, I can't tell the difference.