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Hey Guys,
I"m in the process (a long process) of looking for a new exhaust for the beast, I hear people talk about section 1,2. I was wondering can anyone clarify it more? You get louder noise? more hp?
Thanks :biggrinbounce:
 

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Section 1 is headers

Section 2 is cats

Section 3 are resonators

Section 4, (if there really is a section 4 cause 3 are connected to 4) Are mufflers.
 

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Picture worth a thousand words.

Section1=2nd cats section (bolt-on the pre-cats which integrated in headers)
E60_M5_section1.jpeg

Section2= Resonator section
E60_M5_section2.jpeg

Section3=Muffler/can section
E60_M5_section3.jpeg
 

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You're not going to be able to do Section 1 if where you live has strict emissions testings... Removing the Cats won't fly, and from what I've gathered really quiets the exhaust as well aside of the mufflers... Section 2 I don't think does much besides resonance and tone, though I have no idea
 

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technically headers are still considered part of the engine. The exhaust starts after all the individual cylinders' gasses have coalesced into 1 or 2 pipes. It's confusing because the primary cats are integrated into the headers so you'd think it would be called section 1, but right after the headers are the secondary cats which are section 1.
 

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Here are my experience with all sort of combination I have done:

1) 2nd cats/resonator deleted with stock muffler--> sound a little raspier but not much louder than stock. No backpressure loss feeling.

2) 2nd cats/resonator deleted with Meisterschaft GT muffler--> very loud, and loss some backpressure at low-end torque, but feel it pull harder at top-end RPM. Loudest of all combination section1&2&3 from any manufacturers I ever heard on M5.

3) Prime cats/2nd cats/resonator deleted with race muffler--> very loud, and backpressure loss worst than (2). Feel like turbo lag, but pull hard at top-end RPM. The exhaust tone and note were overpower by the raspy sound from the straight pipes (2nd cat/resonator removed)

Finally 4, I went with prime(pre-) cats deleted, stock 2nd cat/resonator with race muffler--> most exhaust tone determine by characteristic of muffler choice with a little groaning/pulsing from headers. No backpressure loss, but top end doesn't feel strong like (3).

I feel like removing section1&2 in some case could overkill the true exhaust note/tone from the muffler itself. If you want to let the true exhaust note come out, keep the midsections stock.

BTW, with (3) and (4) when removed prime (or pre-) cats, you will have SES light (increase emission)<!-- / message --><!-- edit note -->
 

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Here are my experience with all sort of combination I have done:

1) 2nd cats/resonator deleted with stock muffler--> sound a little raspier but not much louder than stock. No backpressure loss feeling.

2) 2nd cats/resonator deleted with Meisterschaft GT muffler--> very loud, and loss some backpressure at low-end torque, but feel it pull harder at top-end RPM. Loudest of all combination section1&2&3 from any manufacturers I ever heard on M5.

3) Prime cats/2nd cats/resonator deleted with race muffler--> very loud, and backpressure loss worst than (2). Feel like turbo lag, but pull hard at top-end RPM. The exhaust tone and note were overpower by the raspy sound from the straight pipes (2nd cat/resonator removed)

Finally 4, I went with prime(pre-) cats deleted, stock 2nd cat/resonator with race muffler--> most exhaust tone determine by characteristic of muffler choice with a little groaning/pulsing from headers. No backpressure loss, but top end doesn't feel strong like (3).

I feel like removing section1&2 in some case could overkill the true exhaust note/tone from the muffler itself. If you want to let the true exhaust note come out, keep the midsections stock.

<!-- / message --><!-- edit note --> BTW, with (3) and (4) when removed prime (or pre-) cats, you will have SES light (increase emission)
That's a long road you've traveled Kenny! :haha: The only thing left
to try is high flow cats and perhaps high flow resonator with x-pipe.
 

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Guys, this could be a stupid question, but I'm kind of new. Could you leave everything stock but put on an aftermarket exhaust (section 3, I think)? What would this do for performance and sound? Those are the two things I really care about. I was thinking about deleting the resonator for the sound, but want a more aggressive sound altogether while not spending a ton of $. What are your suggestions? Will just a muffler do that for me or do I need to replace everything? If I do muffler and remove resonators, should I do x-pipe or straight pipes??
Thanks for the input
--Graeme
 

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...Could you leave everything stock but put on an aftermarket exhaust (section 3, I think)? What would this do for performance and sound? Those are the two things I really care about. ...
Sound wise? That would be the most conservation and truely appreciate your exhaust note intended by manufacturer.

Performance wise? It barely make hp from section1&2&3, the only way to see hp gain is removing the pre-cat which attached to the headers (TMS) or aftermarket headers (SS, RDS, Evosport). Usually, when running "straight pipe", it gain noticeable hp, but not in this case with M5. Their design is already efficient.

Hope that help.
 

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That's a long road you've traveled Kenny! :haha: The only thing left
to try is high flow cats and perhaps high flow resonator with x-pipe.
That's a part of the modding journey even it kind of hassle from time to time but it's fun.
:cheers:
Only one more power mod for me and I'm done.:byee55amg
 

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Hey Keang24 that was an excellent illustration of sections 1,2 &3.
That says it all. No one should be confused anymore.

M5Ranger
 

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I gained about 10rwhp and 10rwtq from from adding sections 1, 2 and 3. I didnt notice any of the backpressure loss mentioned above but this could be because I added the ecu at the same time. I did dynos but didnt have any driving time between the mods.
 

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I gained about 10rwhp and 10rwtq from from adding sections 1, 2 and 3. I didnt notice any of the backpressure loss mentioned above but this could be because I added the ecu at the same time. I did dynos but didnt have any driving time between the mods.
Thanks. I should have mentioned that I don't have ecu remapped as yet. That would help a lot on throttle response and tunning to accomodate more airflow from exhaust setup.
 
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