Modify stock exhaust to remove flapper
Newbie
Joined: Jun 2008
Posts: 22
Likes: 0
From: South Broward
Thanks for the write up, I was inspired and did mine 
I don't have a welder so I took it to my local shop and show them the pics of yours and we got to work, came out sweet (wish I had my camera 
) Anyway did not dyno my car but it feels better especially in 3rd gear, and not much louder 
Nice diy 10-12 awhp bap! bap!
I don't have a welder so I took it to my local shop and show them the pics of yours and we got to work, came out sweet (wish I had my camera ) Anyway did not dyno my car but it feels better especially in 3rd gear, and not much louder Nice diy 10-12 awhp bap! bap!
Evolved Member
Joined: Apr 2008
Posts: 1,235
Likes: 4
From: PA
why not try to delete the muffler entirely? i am sure it is more work but i can't imagine the sound being much loud. it may sound more aggressive but not too much with that fat cat keeping things in check.
Can you clarify?
What I did is cut the pipe and had a friend weld a peice of metal to block the passage so it doesn't go around to the flapper.
If I can get another stock muffler I'm going to cover the holes on the right side (pic), and weld in a y-pipe after the intial cut.
What I did is cut the pipe and had a friend weld a peice of metal to block the passage so it doesn't go around to the flapper.
If I can get another stock muffler I'm going to cover the holes on the right side (pic), and weld in a y-pipe after the intial cut.
Last edited by El_Kameleon_G; Dec 26, 2009 at 05:35 PM.
Evolving Member
Joined: Mar 2004
Posts: 422
Likes: 0
From: Tx,
i did that too long time ago, cost me 30 dollars.i got some vidz. the flutter valve i think should be removed cause it vibrates on wot. i removed the resonator too.
Last edited by ak47m203; Dec 26, 2009 at 03:44 PM.
Evolving Member
Joined: Mar 2004
Posts: 422
Likes: 0
From: Tx,
here's the modded exhaust and resonator delete.
http://www.motionbox.com/videos/7a9bd9bb141be4c4f5
http://www.youtube.com/user/ak47m203#p/u/1/MG5hfpAKjk8
http://www.youtube.com/user/ak47m203#p/u/2/BQ4k6t3OtPg
compare to stock...
http://video.cardomain.com/VideoPlayer.aspx?id=691786
no video yet with a test pipe.
http://www.motionbox.com/videos/7a9bd9bb141be4c4f5
http://www.youtube.com/user/ak47m203#p/u/1/MG5hfpAKjk8
http://www.youtube.com/user/ak47m203#p/u/2/BQ4k6t3OtPg
compare to stock...
http://video.cardomain.com/VideoPlayer.aspx?id=691786
no video yet with a test pipe.
Last edited by ak47m203; Dec 26, 2009 at 04:35 PM.
Evolving Member
Joined: Mar 2004
Posts: 422
Likes: 0
From: Tx,
works is charging 199 for this...
2008+ Mitsubishi EVO X WORKS Stealth Performance Muffler
Retail: $249.00 $199.00
Shipping: $30.00
This 2008+ Mitsubishi EVO X Stealth Performance Muffler is for those EVO Enthusiasts where exhaust quietness is a strong consideration, the StealthWORKS muffler is your answer. The original design is fairly complex (see image below) with room to improve airflow without sacrificing sound suppression. We take the stock EVO muffler and modify it in-house to produce the most power with the least noise. We cut open the canister, modify the internals for a more direct, unobstructed flow, reweld with stainless steel wire and repaint the canister to a factory black finish. Voila, you have a muffler that looks stock, sounds almost stock, fits perfectly, provides quicker turbo spool and produces more power and torque. The gains may not be as impressive as with the upcoming Exhale AB/ABM, but worth the sound reduction if you're not looking for extra attention. The StealthWORKS muffler is 100% compatible with the stock Intermediate Pipe. Complete with simple installation instructions.
2008+ Mitsubishi EVO X WORKS Performance Muffler
Increase 12 HP / 7 TQ
Direct replacement using OEM muffler canister
Modified internal routing to improve airflow
Improved turbo response, horsepower and torque
WORKS Factory-Matched Warranty
Retail: $249.00 $199.00
Shipping: $30.00
This 2008+ Mitsubishi EVO X Stealth Performance Muffler is for those EVO Enthusiasts where exhaust quietness is a strong consideration, the StealthWORKS muffler is your answer. The original design is fairly complex (see image below) with room to improve airflow without sacrificing sound suppression. We take the stock EVO muffler and modify it in-house to produce the most power with the least noise. We cut open the canister, modify the internals for a more direct, unobstructed flow, reweld with stainless steel wire and repaint the canister to a factory black finish. Voila, you have a muffler that looks stock, sounds almost stock, fits perfectly, provides quicker turbo spool and produces more power and torque. The gains may not be as impressive as with the upcoming Exhale AB/ABM, but worth the sound reduction if you're not looking for extra attention. The StealthWORKS muffler is 100% compatible with the stock Intermediate Pipe. Complete with simple installation instructions.
2008+ Mitsubishi EVO X WORKS Performance Muffler
Increase 12 HP / 7 TQ
Direct replacement using OEM muffler canister
Modified internal routing to improve airflow
Improved turbo response, horsepower and torque
WORKS Factory-Matched Warranty
Sounds great. When at idle, you can tell that something is different - a little deeper, and barely louder. Full throttle is a little louder and more throaty, but cruising at 70, I can't tell a difference (tires are still the predominant noise on the highway).
I wanted a little more noise in the exhaust without it becoming droning on the highway. I couldn't be happier with the results.
I wanted a little more noise in the exhaust without it becoming droning on the highway. I couldn't be happier with the results.