Exhaust question
#16
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an even fire engine like a Porsche H6 doesn't profit from a x-over connection like odd fire v8s. The factory knows this and correctly plumbs it's race and street/race exhausts like on a GT3
GT3
![](https://forums.pelicanparts.com/uploads18/big_997S_031295448610.jpg)
997S
GT3
![](https://forums.pelicanparts.com/uploads18/big_997S_031295448610.jpg)
997S
![](https://forums.pelicanparts.com/uploads18/big_gt3_Excellence1295448696.jpg)
#17
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Exactly !
An X only changes the sound on our motors. There also isn't enough pipe length for us to make an "x" work even if it would on our cars.
An X only changes the sound on our motors. There also isn't enough pipe length for us to make an "x" work even if it would on our cars.
#18
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That could be just 2 small side inlet/outlet mufflers put together in one housing. That is the way the Flow-Masters are done, and on my old Carrera, the difference between that and straight pipes was about 3/4 of a HP.
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Larry Herman
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Larry Herman
2016 Ford Transit Connect Titanium LWB
2018 Tesla Model 3 - Electricity can be fun!
Retired Club Racer & National PCA Instructor
Past Flames:
1994 RS America Club Racer
2004 GT3 Track Car
1984 911 Carrera Club Racer
1974 914/4 2.0 Track Car
CLICK HERE to see some of my ancient racing videos.
#19
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Yes the Flowmasters use multi chambers with internal baffling which is a little different than the Magnaflows with straight thru perforated cores and fiberglass baffling. Neither are really set up for a dual in/dual out for our cars.
#20
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I thought that the Flowmaster was the right way to do it, seeing as how in the one that I had the left side was separate from the right side.
Last edited by Larry Herman; 01-19-2011 at 04:11 PM. Reason: add picture
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If extended straight pipes work without head damage......get the plasma cutter out and lets lose some weight out of the back of this thing.
Flyin Finn-where did you get that pic? I am trying to build a 996 RSR (clone) and need all the pics I can get.
Flyin Finn-where did you get that pic? I am trying to build a 996 RSR (clone) and need all the pics I can get.
#23
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On my 3.2 Carrera it was awesome. Along with the resonator tips that I had, it made the motor sound more like a V8 Ferrari than a flat 6 Porsche. Had that little shriek when you wound it up. Pretty cool.
#24
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Fabspeed also makes a 2x2 crossflow muffler, here's a pic of it's internals, inlet is the lower pipes
![](https://forums.pelicanparts.com/uploads18/fabspeed_muff21295625332.jpg)
![](https://forums.pelicanparts.com/uploads18/fabspeed_muff11295625351.jpg)
#25
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Thanks for the pics, for me personally, I'll stick with 2 individual mufflers. I'm not sold on "x"s working for us and it's just as easy, maybe easier, to design and work 2 separate mufflers into the car than one big one. Just my preference.
Both Flowmaster and Magnaflow have 2x in/2 out xflow mufflers. Like Larry I have a Flowmaster on my '76 hotrod, it sounds great but is loud and would never be allowed to run a a palce like Lime Rock. you are coprrect about the internal designs, the Flowmaster just uses baffles and internal reflection to damp noise, the Magnaflows ate a glasspack desiign w/ perforated cores wrapped w/ ss ot f/g strands. The Magnaflow is quieter.
Fabspeed also makes a 2x2 crossflow muffler, here's a pic of it's internals, inlet is the lower pipes
![](https://forums.pelicanparts.com/uploads18/fabspeed_muff21295625332.jpg)
![](https://forums.pelicanparts.com/uploads18/fabspeed_muff11295625351.jpg)
Fabspeed also makes a 2x2 crossflow muffler, here's a pic of it's internals, inlet is the lower pipes
![](https://forums.pelicanparts.com/uploads18/fabspeed_muff21295625332.jpg)
![](https://forums.pelicanparts.com/uploads18/fabspeed_muff11295625351.jpg)
#26
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ltusler - getting ready to do this and started wondering about the O2 sensors???? I don't see any at all in your pics. Are you running stand alone EMS or ?????
#27
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Thanks Bill, great shots. I think I may build a Magnaflo to try and meet Limerocks db standards this year as my old busted up Flowmaster 80 with the baffles pounded into the tail pipes just won't hack it anymore..
#28
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I hope that the Magnaflow works for you but suspect not, given how tough they have been getting. I do have some other ideas for someone with some welding skills.
The key to a good flowing muffled exhaust is to get muffler volume. the Fabspeed is better because it is bigger. The wrapped perforated core is going to silence better than the baffled core but flow worse, Viking is correct 2 long separate cores will be better, even if they are in the same case. The Fabspeeed would be much quieter if the 2 cores were extended so one internal turn up is at one end and the other at the opposite end. The external plumbing will also be asymmetric. The next thing to try is a trick that I knew of but had never seen implemented, It was on a BMW exhaust. Your BMW may have the same thing, look for an exhaust can that only has an Inlet, no outlet. It does work.
#30