I'm trying to keep the exhaust as quiet as possible - should I run a catless DP with Cobb's Stage 2 and keep the stock catback? I know I'll lose some power, but I'm trying to keep the noise levels down.

Are there risks to the midpipe cats due to increased EGT's from the new map?

Any suggestions would be appreciated - my goal is to get the AP stage 2 on with a minimal difference in noise levels from stock.

-Ryan

full turboback with stock muffler should be fine, it wont rob you of too too much power I don't believe, as long as you have a DP

full turboback with stock muffler should be fine, it wont rob you of too too much power I don't believe, as long as you have a DP

Are you telling me that deleting the dp and midpipe cats won't increase noise levels? Cats do a lot of work in dampening sound, don't they?

-Ryan

i think golfa is saying that the power loss due to having the stock muffler versus an aftermarket won't be too big... as for noise i'm sure there will be some difference how much i don't know...

I got a Helix catted downpipe and a Greddy Evo catback. Barely louder than stock at idle, but at WOT it opens up nicely(but not too loud). It's a good combo if you ask me....BTW, I also got the Accessport. VERY FUN!:devil:



Mika

I ran the Cobb catted downpipe with stock cat-back for about a week while waiting on my Borla Hush. The only noise difference I noticed was a bit more turbo sound inside the car, from outside the thing was so quiet I couldn't tell the difference from stock.

I ran the Cobb catted downpipe with stock cat-back for about a week while waiting on my Borla Hush. The only noise difference I noticed was a bit more turbo sound inside the car, from outside the thing was so quiet I couldn't tell the difference from stock.

That tells me something - but what about a no-cat dp?

A full DP will remove the 2 cats...

You can look into a shorty DP, then have a cat in mid section, or even a resonator (or both) to keep it quiet.

For now I am looking at the MadDad divorced DP w/ cat, and the 3rd cat eliminator pipe. There is an option for a 3" mid extension that could adapt to the stock 2.5" axleback. I like the look and design, plus the 3rd cat eliminator pipe looks like there's a cat on it (heat shield)...good to trick people if anyone looks.

Also they offer Stromungs high flow 3rd cat, if you choose to get a shorty catless DP.

daddysscp.com is a vendor here...

has anyone ran an sti with the stock muffler and a down pipe in stage 2? I am planning on doing this with a catted cobb DP.

sam

That tells me something - but what about a no-cat dp?

I doubt there's any noticable difference with no cat, the high flow cat in the Cobb dp didn't look to be much of a restriction compared to a normal ceramic brick cat.