znod

I asked if it was a cat back system and they said no, since the 545i has a resonator that they don't remove/replace--it's just a muffler and tips.
[/quote]That's interesting. They must want it to be quieter than the rest. Supposedly, at the end of September, Dinan was supposed to have, in addition to the lightweight flywheel and trottle body, at least an intake and, apparently, a muffler, tubing to tips, and tips. Eventually, they are supposed to have a MAF and programming.
[/quote]

As far as I know, none of the sport exhausts available for the 545i (B&B, Remus, Eisenmann, etc.) are cat back systems--all are just mufflers and tips.

Several forum members have these exhausts. Anybody who has them--are they cat back systems or just mufflers and tips?
[/quote]
My B&B is cat back. That is, both mufflers/resonators are gone, and there is nothing between the B&B exhaust and the cats. I mostly assumed that the others are cat backs since I never dreamed anyone would leave a factory muffler in the system. But, Dinan, knows what it is doing, and probably there is not much more HP to be gained by eliminating the other resonator.
[/quote]

Your B&B must be different than the one they show on their website, and the one that I'm familiar with. The one on their site is described by them as a "direct replacement muffler" and as the pic on their site shows is not a cat back system.
http://www.bbexhaust.com/New/auto-fl...?page=e60.html

Where did you get yours? I'd be interested in seeing pix of their cat back system--do you have any of yours?
[/quote]
Nope, no pics of what you want. The link you posted shows the only exhaust piece B&B makes for the 545i. It's cat back; the pic doesn't show all the tubing. Maybe you can make something concrete from the pics below. They mirror the discussion found here:

Update: Report ... B&B ...

I could take a better photo for you tomorrow if you want. But, you might enjoy the thread I linked above. There's some interesting info about B&B there--including my fun experience with B&B.

jet190rs

I asked if it was a cat back system and they said no, since the 545i has a resonator that they don't remove/replace--it's just a muffler and tips.
[/quote]That's interesting. They must want it to be quieter than the rest. Supposedly, at the end of September, Dinan was supposed to have, in addition to the lightweight flywheel and trottle body, at least an intake and, apparently, a muffler, tubing to tips, and tips. Eventually, they are supposed to have a MAF and programming.
[/quote]

As far as I know, none of the sport exhausts available for the 545i (B&B, Remus, Eisenmann, etc.) are cat back systems--all are just mufflers and tips.

Several forum members have these exhausts. Anybody who has them--are they cat back systems or just mufflers and tips?
[/quote]
My B&B is cat back. That is, both mufflers/resonators are gone, and there is nothing between the B&B exhaust and the cats. I mostly assumed that the others are cat backs since I never dreamed anyone would leave a factory muffler in the system. But, Dinan, knows what it is doing, and probably there is not much more HP to be gained by eliminating the other resonator.
[/quote]

Your B&B must be different than the one they show on their website, and the one that I'm familiar with. The one on their site is described by them as a "direct replacement muffler" and as the pic on their site shows is not a cat back system.
http://www.bbexhaust.com/New/auto-fl...?page=e60.html

Where did you get yours? I'd be interested in seeing pix of their cat back system--do you have any of yours?
[/quote]
Nope, no pics of what you want. The link you posted shows the only exhaust piece B&B makes for the 545i. It's cat back; the pic doesn't show all the tubing. Maybe you can make something concrete from the pics below. They mirror the discussion found here:

Update: Report ... B&B ...

I could take a better photo for you tomorrow if you want. But, you might enjoy the thread I linked above. There's some interesting info about B&B there--including my fun experience with B&B.
[/quote]

Doesn't cat back means it replaces everything behind the catalytic converters? That means a cat back exhaust system would run from underneath the engine all the way to the rear of the car. It would replace the last 3 components of this sequence:
1) engine
2) catalytic converters
3) 2 small resonators
4) 1 big Y shaped resonator
5) muffler

The B&B looks like its just the muffler (and the tubes that extend to the big Y resonator). I don't believe that's cat back.

stream

I asked if it was a cat back system and they said no, since the 545i has a resonator that they don't remove/replace--it's just a muffler and tips.
[/quote]That's interesting. They must want it to be quieter than the rest. Supposedly, at the end of September, Dinan was supposed to have, in addition to the lightweight flywheel and trottle body, at least an intake and, apparently, a muffler, tubing to tips, and tips. Eventually, they are supposed to have a MAF and programming.
[/quote]

As far as I know, none of the sport exhausts available for the 545i (B&B, Remus, Eisenmann, etc.) are cat back systems--all are just mufflers and tips.

Several forum members have these exhausts. Anybody who has them--are they cat back systems or just mufflers and tips?
[/quote]
My B&B is cat back. That is, both mufflers/resonators are gone, and there is nothing between the B&B exhaust and the cats. I mostly assumed that the others are cat backs since I never dreamed anyone would leave a factory muffler in the system. But, Dinan, knows what it is doing, and probably there is not much more HP to be gained by eliminating the other resonator.
[/quote]

Your B&B must be different than the one they show on their website, and the one that I'm familiar with. The one on their site is described by them as a "direct replacement muffler" and as the pic on their site shows is not a cat back system.
http://www.bbexhaust.com/New/auto-fl...?page=e60.html

Where did you get yours? I'd be interested in seeing pix of their cat back system--do you have any of yours?
[/quote]
Nope, no pics of what you want. The link you posted shows the only exhaust piece B&B makes for the 545i. It's cat back; the pic doesn't show all the tubing. Maybe you can make something concrete from the pics below. They mirror the discussion found here:

Update: Report ... B&B ...

I could take a better photo for you tomorrow if you want. But, you might enjoy the thread I linked above. There's some interesting info about B&B there--including my fun experience with B&B.
[/quote]

Doesn't cat back means it replaces everything behind the catalytic converters? That means a cat back exhaust system would run from underneath the engine all the way to the rear of the car. It would replace the last 3 components of this sequence:
1) engine
2) catalytic converters
3) 2 small resonators
4) 1 big Y shaped resonator
5) muffler

The B&B looks like its just the muffler (and the tubes that extend to the big Y resonator). I don't believe that's cat back.
[/quote]

Correct. The B&B (and Remus, Eisenmann, Dinan, etc.) are mufflers with tips and a few feet of pipe on the other side, that connect to the exhaust system after the last resonator--so I suppose you could call them resonator back, but they are not cat back systems as the term is used in the auto industry.

KrisD

I asked if it was a cat back system and they said no, since the 545i has a resonator that they don't remove/replace--it's just a muffler and tips.
[/quote]That's interesting. They must want it to be quieter than the rest. Supposedly, at the end of September, Dinan was supposed to have, in addition to the lightweight flywheel and trottle body, at least an intake and, apparently, a muffler, tubing to tips, and tips. Eventually, they are supposed to have a MAF and programming.
[/quote]

As far as I know, none of the sport exhausts available for the 545i (B&B, Remus, Eisenmann, etc.) are cat back systems--all are just mufflers and tips.

Several forum members have these exhausts. Anybody who has them--are they cat back systems or just mufflers and tips?
[/quote]

i have an AC Schnitzer on my 545 and it consists of only a muffler and tips. the stock muffler and resonator were removed, which probably dropped nearly 30 lbs. the Schnitzer is pricey - more so than Dinan with surely an identical increase in flow (HP). if you are looking for V8 growl with a sophisticated note and low cab noise, this is the way to go IMO.

znod

I asked if it was a cat back system and they said no, since the 545i has a resonator that they don't remove/replace--it's just a muffler and tips.
[/quote]That's interesting. They must want it to be quieter than the rest. Supposedly, at the end of September, Dinan was supposed to have, in addition to the lightweight flywheel and trottle body, at least an intake and, apparently, a muffler, tubing to tips, and tips. Eventually, they are supposed to have a MAF and programming.
[/quote]

As far as I know, none of the sport exhausts available for the 545i (B&B, Remus, Eisenmann, etc.) are cat back systems--all are just mufflers and tips.

Several forum members have these exhausts. Anybody who has them--are they cat back systems or just mufflers and tips?
[/quote]
My B&B is cat back. That is, both mufflers/resonators are gone, and there is nothing between the B&B exhaust and the cats. I mostly assumed that the others are cat backs since I never dreamed anyone would leave a factory muffler in the system. But, Dinan, knows what it is doing, and probably there is not much more HP to be gained by eliminating the other resonator.
[/quote]

Your B&B must be different than the one they show on their website, and the one that I'm familiar with. The one on their site is described by them as a "direct replacement muffler" and as the pic on their site shows is not a cat back system.
http://www.bbexhaust.com/New/auto-fl...?page=e60.html

Where did you get yours? I'd be interested in seeing pix of their cat back system--do you have any of yours?
[/quote]
Nope, no pics of what you want. The link you posted shows the only exhaust piece B&B makes for the 545i. It's cat back; the pic doesn't show all the tubing. Maybe you can make something concrete from the pics below. They mirror the discussion found here:

Update: Report ... B&B ...

I could take a better photo for you tomorrow if you want. But, you might enjoy the thread I linked above. There's some interesting info about B&B there--including my fun experience with B&B.
[/quote]

Doesn't cat back means it replaces everything behind the catalytic converters? That means a cat back exhaust system would run from underneath the engine all the way to the rear of the car. It would replace the last 3 components of this sequence:
1) engine
2) catalytic converters
3) 2 small resonators
4) 1 big Y shaped resonator
5) muffler

The B&B looks like its just the muffler (and the tubes that extend to the big Y resonator). I don't believe that's cat back.
[/quote]

Correct. The B&B (and Remus, Eisenmann, Dinan, etc.) are mufflers with tips and a few feet of pipe on the other side, that connect to the exhaust system after the last resonator--so I suppose you could call them resonator back, but they are not cat back systems as the term is used in the auto industry.
[/quote]
I am seeing the light. It is my dumb apparently--unfamiliarity with BMWs. What was removed was the two, what I would call, large mufflers. I did not realize that there was at least one resonator (small auxilary muffler). I did not pay that much attention. I am used to cars such that once "the" muffler(s) are removed all that is left is the cat(s) and precat(s). I'll have to look much more carefully. But, something seems strange. I have:

1) I know I have one of these--"engine"
2) Apparently, I have not seen them--"catalytic converters" Are they readily visible?
3) I quess they are there somewhere--"2 small resonators"
4) I will look carefully, but I haven't seen--"1 big Y shaped resonator" Is that what was removed?--the muffler(s)?
5) 2 mufflers (removed) as 1 piece--or is that the "muffler."

Help me with my apparent confusion. I am not used to so many mufflers/resonators. But, the main point is that apparently even the B&B is not, strictly speaking, cat back--although, from the cost perspective referred to initially, it has the same features as a typical cat-back system--tubing fore and aft, muffler, and tips. I agree that the B&B is not cat-back strictly speaking since apparently there is at least 1 resonator between it and the cats.

znod

Thanks to all, and, to all, a good night. I'll check in tomorrow to see what's up. Thanks for indulging my fantasy so politely.

Incidentally, when you (Stream) said "I asked if it was a cat back system and they said no, since the 545i has a resonator that they don't remove/replace--it's just a muffler and tips," I thought you meant that the Dinan system removed only 1 of what I am calling the two mufflers. Perhaps the removed part should simply be referred to as the muffler.

stream

Yeah--the 545i exhaust system has quite a few components. The stock "muffler" is actually 2 mufflers (one of which has a flap that is closed at low speed for reduced sound), and there are a few resonators and a catalytic converter.

All the "exhaust systems" for the 545i are mufflers & tips--I suppose it's good marketing to call it an exhaust system (sounds more expensive than a muffler... ).

znod

Yeah--the 545i exhaust system has quite a few components. The stock "muffler" is actually 2 mufflers (one of which has a flap that is closed at low speed for reduced sound), and there are a few resonators and a catalytic converter.

All the "exhaust systems" for the 545i are mufflers & tips--I suppose it's good marketing to call it an exhaust system (sounds more expensive than a muffler... ).
[/quote]
I'm still up after all. I'll going to put my car back on my ramps soon and look around some more. Thanks for the help and clarifications.

znod

Follow up. I wonder how much louder the 545i would be without the resonator(s) before the muffler and how much actual restriction it (they) cause. If they add little restriction, then the existing aftermarket systems, in effect, do the job of a cat-back system since doing a whole cat back would add little but cost. And, back to an earlier point--the cost of the existing systems is consistent with existing cat-back systems as are their components--except, in some cases, not as much tubing is present after the muffler.

stream

Here's what the 545i exhaust system consists of.

Front section w/ catalytic converters:
http://www.realoem.com/bmw/showparts.do?mo...531&hg=18&fg=10


Front resonators:
http://www.realoem.com/bmw/showparts.do?mo...532&hg=18&fg=10


Rear section, icluding rear resonators, mufflers & tips (the aftermarket exhausts replace parts 2 & 13 below):
http://www.realoem.com/bmw/showparts.do?mo...533&hg=18&fg=20