DIY - Custom Exhaust
#11
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Step 8:
Unbolt front muffler exhaust hanger and push the factory muffler over. Gotta be able to get this pipe in and out.
Weld it all up, but leave one joint. Test fit a second time.
Be sure to cover your exhaust tips with a towel so you dont scratch your bumper.
![](http://www.primal-hosting.com/images/BMW545i/Exhaust/BMWS8-1.JPG)
![](http://www.primal-hosting.com/images/BMW545i/Exhaust/BMWS8-2.JPG)
![](http://www.primal-hosting.com/images/BMW545i/Exhaust/BMWS8-3.JPG)
Unbolt front muffler exhaust hanger and push the factory muffler over. Gotta be able to get this pipe in and out.
Weld it all up, but leave one joint. Test fit a second time.
Be sure to cover your exhaust tips with a towel so you dont scratch your bumper.
#12
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Step 9:
Clamp or weld it. If you're mean like me, make them drop the entire exhaust and tig weld it off car.
Next up - serious butt dyno action. Let's see how she rolls now.
Next weekend - new muffler. The stock one is just too bulky. Probably save 10lbs replacing it. Doubt there is much advantage beyond that though.
![](http://www.primal-hosting.com/images/BMW545i/Exhaust/BMWS9-1.JPG)
![](http://www.primal-hosting.com/images/BMW545i/Exhaust/BMWS9-2.JPG)
Clamp or weld it. If you're mean like me, make them drop the entire exhaust and tig weld it off car.
Next up - serious butt dyno action. Let's see how she rolls now.
Next weekend - new muffler. The stock one is just too bulky. Probably save 10lbs replacing it. Doubt there is much advantage beyond that though.
#13
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I was intending on replacing the front half of the exhaust and resonator, but after inspection, it's all nicely mandrel bent, correctly sized tubing. The stock resonators are a nice straight through design. No need to replace. This section we've just removed is probably 95% of the flow restriction in the entire exhaust (note: I'm excluding that comment for the headers - holy crap what a pile of junk those are.)
The total cost on this system was under $300.
The total cost on this system was under $300.
#15
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Join Date: Sep 2007
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My Ride: 530i
Mods: M5 sporty package, M5 Steering wheel, Sprint Booster
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Originally Posted by crmb' post='889816' date='May 26 2009, 07:12 AM
You can actually weld this up halfway dropped off the car. This way no high frequency can affect the electronics.
![Big Grin](https://5series.net/forums/images/smilies/imported/biggrin.gif)
#18
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So... The sound is pretty disappointing. The stock mufflers are like super mufflers or something, as it doesn't sound much different until you get on it. The car feels very strong tho.
I'm debating between running one of my all time favorite mufflers (borla - http://store.summitracing.com/partde...art=BOR-40652) or possibly one of the new aeroturbine stealth mufflers... Ahhh.. Decisions, decisions.
I'm debating between running one of my all time favorite mufflers (borla - http://store.summitracing.com/partde...art=BOR-40652) or possibly one of the new aeroturbine stealth mufflers... Ahhh.. Decisions, decisions.
#20
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Join Date: Feb 2008
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My Ride: BMW 535xi
Model Year: 2008
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Very professionally done. And just as professional was the time and effort you took to write and post photos in sequence. Well done!