Is true dual exhaust overrated for perfomance
#32
Rennlist Member
#35
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Hi all!
I'm new here but have been tinkering with my 928 for a while now. I had a new exhaust installed a few weeks ago after reading a ton of internet posts and listening to a bunch of youtube clips. I wanted something that made power, sounds good at idle, is quiet on the highway, loud when the skinny peddle is on the carpet and NEVER sound like a Chevrolet with the muffler cut off. I think I got it right.
What I did was reuse the factory exhaust flanges and head pipes and sent them into mandrel bent 2.5" as soon as possible. From there it goes into a Magnaflow 2.5"-->3" Y pipe that has the O2 fitting on top which is just past the bell housing. The Y pipe leads to a high flow cat in the factory cat location. Just after the cat I had a flange installed so that I could pull the forward section like the factory set up. From there back it is 3" mandrel bent into an 18" Magnaflow in the stock muffler location. I had a big oval stainless tip installed in the factory cut out. The out side of the muffler was cut way back to make room for the tip to sit in the same spot as the factory pipes. I was able to reuse all of the factory heat shields and hangers.
It sounds just like I wanted it to and seems to add a little power to the butt dyno. There was a guy with a new SS Camaro on the rack next to my 928 that was jealous of how good my car sounds. The guys in the exhaust shop all were very impressed with how good this little European thing sounded. This weekend we had a Euro car meet and there was no question I had the best sounding car there. I’m at work now and do not have a video clip or pictures with me but can add some later tonight.
I'm new here but have been tinkering with my 928 for a while now. I had a new exhaust installed a few weeks ago after reading a ton of internet posts and listening to a bunch of youtube clips. I wanted something that made power, sounds good at idle, is quiet on the highway, loud when the skinny peddle is on the carpet and NEVER sound like a Chevrolet with the muffler cut off. I think I got it right.
What I did was reuse the factory exhaust flanges and head pipes and sent them into mandrel bent 2.5" as soon as possible. From there it goes into a Magnaflow 2.5"-->3" Y pipe that has the O2 fitting on top which is just past the bell housing. The Y pipe leads to a high flow cat in the factory cat location. Just after the cat I had a flange installed so that I could pull the forward section like the factory set up. From there back it is 3" mandrel bent into an 18" Magnaflow in the stock muffler location. I had a big oval stainless tip installed in the factory cut out. The out side of the muffler was cut way back to make room for the tip to sit in the same spot as the factory pipes. I was able to reuse all of the factory heat shields and hangers.
It sounds just like I wanted it to and seems to add a little power to the butt dyno. There was a guy with a new SS Camaro on the rack next to my 928 that was jealous of how good my car sounds. The guys in the exhaust shop all were very impressed with how good this little European thing sounded. This weekend we had a Euro car meet and there was no question I had the best sounding car there. I’m at work now and do not have a video clip or pictures with me but can add some later tonight.
#36
Nordschleife Master
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Here is some 16V love.
![](https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/402472_180099242090480_151266858307052_235029_1299117391_n.jpg)
![](https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/409561_180098525423885_151266858307052_235028_1882963394_n.jpg)
Car is daily driven, just put in a good used transmission, fixed intermediate plate, and made this true 3" back system with a V-band flange to mate. All TIG welded, with a Magnaflow muffler. It is about the same volume as a 928S4 with X pipe large 87 mids and RMB and no cats. Very deep sound.
![](https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/402472_180099242090480_151266858307052_235029_1299117391_n.jpg)
![](https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/409561_180098525423885_151266858307052_235028_1882963394_n.jpg)
Car is daily driven, just put in a good used transmission, fixed intermediate plate, and made this true 3" back system with a V-band flange to mate. All TIG welded, with a Magnaflow muffler. It is about the same volume as a 928S4 with X pipe large 87 mids and RMB and no cats. Very deep sound.
#38
Drifting
Thread Starter
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Looks very nice. Yes with the added flow and light weight I believe you have added performance. Pics of mine coming soon. Is there anyway you can also add a video so we can hear it?
#42
Official Bay Area Patriot
Fuse 24 Assassin
Rennlist Member
Fuse 24 Assassin
Rennlist Member
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I won't be using a tube since I'm gong to try and fit an 18" long glass pack on the driver side intermediate muffler location to tone down the drone. The heat shield is going bye-bye on the passenger side too so I can do my transmission fluid and filter maintenance with ease.
![Big Grin](https://rennlist.com/forums/images/smilies/biggrin.gif)
#43
Rennlist Member
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I won't be using a tube since I'm gong to try and fit an 18" long glass pack on the driver side intermediate muffler location to tone down the drone. The heat shield is going bye-bye on the passenger side too so I can do my transmission fluid and filter maintenance with ease. ![Big Grin](https://rennlist.com/forums/images/smilies/biggrin.gif)
![Big Grin](https://rennlist.com/forums/images/smilies/biggrin.gif)
The drone is harmonics of the engine/exhaust, NOT the muffler. A GP wont solve that problem for you.
and the tube doesnt need a heat shield..doesnt get hot...no air moves in it.
#44
Official Bay Area Patriot
Fuse 24 Assassin
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Fuse 24 Assassin
Rennlist Member
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I also wanted to keep one less pipe in that vicinity as well. The drone will not be any worse than it is now with dual single chamber Flowmasters.
#45
Rennlist Member
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If you currently have dual tubes from the ending, to two cans...then yes, going to one will -add- engine exhaust resonance right bout 140hz down the highway.
Your flowmaster drone..is post muffler, a SINGLE exhaust from the engine, is a whole new noise.