I'm in the midst of deciding how I should decrease the volume of my exhuast while maintaining or decreasing backpressure and would like some assitance. I'm only looking at altering the Cat-Back section of the exhaust system. Any thoughtful input/comments would be appreciated.
Current set up:
Invidia DW catless DP
3" Ebay "Cobb" knock off catback, original straight through muffler has been removed, in its place...
3" Flowmaster Series 50 chambered muffler (ended up not being any quieter than the original Cobb style muffler, just sounds different and likely adds backpressure)
And a 3" high flow cat welded in at the begining of the mid-pipe, right after it connects to the DP flange.
I have already purchased a 3" inlet 16" long resonator thinking I'll use it in my solution but am not married to using it.
Requirements in order of importance:
-As a point of reference, I had a catless DP with a Borla Hush on my 04 STi and though it was perfect at the time and it would be acceptable now but a hair louder than ideal for my current aging taste.
-Must flow better or at least no worse than my current set up and/or not hinder ~380whp
-Cheaper is better
Options so far:
1.) Weld 16" resonator in midpipe & weld old "Cobb" style muffler in mid-pipe as well, leaving the current flomaster muffler where its at (yes, thats 1 resonator & two mufflers) This is the most quiet option, but will it significantly add back pressure? Can a straight through resonator/muffler add much backpressure?
2.) Replace the flow master with the original Cobb style muffler and weld the 16" resonator into the mid pipe. The reason for this option is that I've read the chambered mufflers actually do add backpressure relative to a straight through muffler, hence this set up should decrease volume as well as increase flow... in Theory, but in practice?
3.) Buy another resonator, weld two into the mid pipe and replace the flowmaster with the original "Cobb" style muffler. This would cost another $40 in parts but *should* flow the best and give a low volume level. Could sell the flowmaster for a few bucks though...
4.) Buy a dnynomax VT muffler and just weld it in place of the flowmaster. Possibly add in the resonator I've already bought. Just did a little reading on these valved mufflers and they seem interesting but I've never had one or known someone who has. I think they're around $100+
Yes, I should have just bought a more stealth exhuast to begin with but I wasn't concerned with noise when I started modding this car. It didn't become a priority till recently. And now I can't bring myself to drop $600 on a new catback. Oh well, live and learn I guess...
Thoughts?
Current set up:
Invidia DW catless DP
3" Ebay "Cobb" knock off catback, original straight through muffler has been removed, in its place...
3" Flowmaster Series 50 chambered muffler (ended up not being any quieter than the original Cobb style muffler, just sounds different and likely adds backpressure)
And a 3" high flow cat welded in at the begining of the mid-pipe, right after it connects to the DP flange.
I have already purchased a 3" inlet 16" long resonator thinking I'll use it in my solution but am not married to using it.
Requirements in order of importance:
-As a point of reference, I had a catless DP with a Borla Hush on my 04 STi and though it was perfect at the time and it would be acceptable now but a hair louder than ideal for my current aging taste.
-Must flow better or at least no worse than my current set up and/or not hinder ~380whp
-Cheaper is better
Options so far:
1.) Weld 16" resonator in midpipe & weld old "Cobb" style muffler in mid-pipe as well, leaving the current flomaster muffler where its at (yes, thats 1 resonator & two mufflers) This is the most quiet option, but will it significantly add back pressure? Can a straight through resonator/muffler add much backpressure?
2.) Replace the flow master with the original Cobb style muffler and weld the 16" resonator into the mid pipe. The reason for this option is that I've read the chambered mufflers actually do add backpressure relative to a straight through muffler, hence this set up should decrease volume as well as increase flow... in Theory, but in practice?
3.) Buy another resonator, weld two into the mid pipe and replace the flowmaster with the original "Cobb" style muffler. This would cost another $40 in parts but *should* flow the best and give a low volume level. Could sell the flowmaster for a few bucks though...
4.) Buy a dnynomax VT muffler and just weld it in place of the flowmaster. Possibly add in the resonator I've already bought. Just did a little reading on these valved mufflers and they seem interesting but I've never had one or known someone who has. I think they're around $100+
Yes, I should have just bought a more stealth exhuast to begin with but I wasn't concerned with noise when I started modding this car. It didn't become a priority till recently. And now I can't bring myself to drop $600 on a new catback. Oh well, live and learn I guess...
Thoughts?