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Discussion Starter #1
Anyone else think this is a good idea for some vendor to fab up?

I want to add headers to my supersprint race setup but don't want my car to become unbearable on the hwy...i.e. cant even hear yourself think. I know most E46M3 owners add a rasp pipe/resonator to fix this problem but we don't really have that option for our cars.

What do you guys think? I asked over at Zpost but that board is slow right now.
 

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S54=Living on the Edge
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I plan to replace the secodary cat section with 2 straight pipes. That should free up some power, change the sound (possibility for a muffler too) and since these cats are not monitored, the ECU/DME should see no difference.
 

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I plan to replace the secodary cat section with 2 straight pipes. That should free up some power, change the sound (possibility for a muffler too) and since these cats are not monitored, the ECU/DME should see no difference.
-You'd want to put in a resonator (like my setup), or else it'll be very loud and raspy. BUT, you absolutely MUST get intelligent software (ESS) when you pull the secondary cats or else you'll lose about 20hp off the top end - speaking from personal experience/dynos.
 

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Discussion Starter #6
Earl- how much would bms charge me to fab up a section 1 like yours? I assume it would mate up to my supersprint since it mates up to stock section 1.

Thanks!
 

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Earl- how much would bms charge me to fab up a section 1 like yours? I assume it would mate up to my supersprint since it mates up to stock section 1.

Thanks!
-Section 1 is the mufflers, section 2 is the x-pipe, and section 3 is the cat delete/resonator. If you are talking about the cat delete section I'd have to say I really don't know. There's only one, and there was no plan to take it to production. I don't know if jigs exist, but I can ask Jose at JPP (the fabber of the exhaust). I should mate up to stock exhaust "joints", but once you start throwing two aftermarket pieces together there are no guarantees.
 

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Discussion Starter #8
Thanks Earl. Any info you have would be appreciated (Could the guy fab another up, what resonator did you use...magnaflow?, cost). If you would rather PM me than put that info in the post, please feel free.

Thanks all.
 

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S54=Living on the Edge
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-You'd want to put in a resonator (like my setup), or else it'll be very loud and raspy. BUT, you absolutely MUST get intelligent software (ESS) when you pull the secondary cats or else you'll lose about 20hp off the top end - speaking from personal experience/dynos.
Thanks Palantirion. Found your old post where you had done a detailed analysis. I had almost forgotten about it.

http://www.bimmerfest.com/forums/showthread.php?p=3460717#post3460717

Looks like the BMS Stage 2 (x-pipe and mufflers) is a good place to start to get some gains w/o a software upgrade. And it looks like the setup would work well with the RPI scoop too. :thumbup:
 

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Thanks Earl. Any info you have would be appreciated (Could the guy fab another up, what resonator did you use...magnaflow?, cost). If you would rather PM me than put that info in the post, please feel free.

Thanks all.
-I've already received an email back from Jose and he's not sure if he made a jig for the cat delete section. He said he'd check on it and get back to me.

Thanks Palantirion. Found your old post where you had done a detailed analysis. I had almost forgotten about it.

http://www.bimmerfest.com/forums/showthread.php?p=3460717#post3460717

Looks like the BMS Stage 2 (x-pipe and mufflers) is a good place to start to get some gains w/o a software upgrade. And it looks like the setup would work well with the RPI scoop too. :thumbup:
-The BMS Stage 2 is the best performing Z4 M exhaust I've come across, and it works even better with the RPI scoop, and even better with ESS's N/A software. I'm really not sure if the midrange punch of the experimental Stage 3 section is worth the deduced high-rpm power loss (relative to the Stage 2). As soon as I break in my CFR500 I'm going to dyno with the Stage 3 and then switch back to the Stage 2, reset DME adaptations and dyno again. Then we'll all know.
 

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Sorry if this is a stupid question but, what is the difference between the S-pipes (w/no cats) that SuperSprint sells and "a resonator"? I'm about to have the SS headers and s-pipe w/o cats added to my BMS x-pipe and SS mufflers. Is my car going to be ridiculously loud?
 

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Wow, that's brutal Pal, I guess it was a stupid question. Let me see if I can ask it a different way. When people on this board (and others) refer to a "resonator" are they simply referring to a muffled section of exhaust, or is it something different?

I understand that the "straight pipes" from SS are non-muffled, non-cat "s-pipes" that may make a bit more power and that they do make a version with cats to make up for the integrated cats that are lost when you swap out the US OEM headers...but do the cats in the alternate SS mid-section (section 3) equal "a resonator". Is the section muffled as well as containing a cat, or does the cat itself muffle some of the sound?
 

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S54=Living on the Edge
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A resonator is typically a smaller muffler that is designed to be (usually) mounted inline along some section of the exhaust between the cat(s) and the muffler(s). A resonated mid-pipe(s) vs s-pipes (straight pipes) will yield a lower sound, but more importantly less rasp and less vibration in the cabin. And since a properly sized resonator is basically a straight through section with sound packing all around, you dont lose flow but reduce NVH at the cost of some added weight.

Hope that helps?

BTW, if I were to get a resonated mid-pipe, I would just have a good muffler shop fab it up rather than pay $$ for the SS s-pipes and have a shop cut it up to weld on a resonator.

A cat will def cut down on the NVH as well in the mid-pipe section.
 
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