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      12-17-2020, 06:57 PM   #1
D CHOI
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exhaust notes doesn't sound right anymore

-bm3 stage 2 acn 91
-fabspeed 200 cell hjs downpipe (throws code now but turned off monitoring)
-fi catback exhaust
-vrsf 5" fmic + chargepipe
-ngk colder plugs (replaced before summer due to engine chocking and burbles sound better after)
___________________________________________
Car doesn't sound as loud and solid and sharp as before. The burbles aren't as crispy and doesn't pop right. During cold start it isn't as loud and the engine note doesn't sound as crispy.

I've used 100 octane mix before and full 100 octane with proper mapping. Also used e85 1 gallon mix and e30 map as well.

Also with 200 cell cat gone bad throwing code will long term use of it being coded off cause any issues? Is maybe my cat being clogged causing these issues? I've done some bm3 datalogging and everything seems fine.

Car isn't as enjoyable to drive anymore and would like someone knowledgeable to help please.

Last edited by D CHOI; 12-22-2020 at 07:10 AM..
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      12-18-2020, 01:42 AM   #2
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I've got the same issue too but I'm completely stock. I have the AA high flow 🤷🏻*♂️
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      12-18-2020, 08:59 AM   #3
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Quote:
Originally Posted by D CHOI View Post
fabspeed 200 cell hjs downpipe (throws code now but turned off monitoring)
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Originally Posted by ryancastano View Post
I have the AA high flow
Your cats are probably clogged:

https://f87.bimmerpost.com/forums/sh...5#post27017165
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      12-18-2020, 01:17 PM   #4
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I don't know what's going on, but it seems like you're the third guy this week with a clogged cat. Just drop your DP and see what it looks like, if it's anything but a perfect grid then you've got a problem.
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      12-18-2020, 02:54 PM   #5
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Thanks guys I will take a look at my cat and probably go catless because I've always thought the sound wasn't loud enough. Then swap back stock for smog. The bm3 turn off cat monitoring will not pass smog as that needs to be on.

This is my 2nd fabspeed dp as they warranty my 1st one. They don't seem to last a year for me and throws code...maybe because the way I drive with aggressive burbles and pops all the time.

Also maybe some mix of e85 in the tank hurts the cat too?
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      12-18-2020, 02:59 PM   #6
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Quote:
Originally Posted by D CHOI View Post
Thanks guys I will take a look at my cat and probably go catless because I've always thought the sound wasn't loud enough. Then swap back stock for smog. The bm3 turn off cat monitoring will not pass smog as that needs to be on.

This is my 2nd fabspeed dp as they warranty my 1st one. They don't seem to last a year for me and throws code...maybe because the way I drive with aggressive burbles and pops all the time.

Also maybe some mix of e85 in the tank hurts the cat too?
If you have aggressive pops and are running high octant race fuel theres probably a good chance you melted or damaged the cat core
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      12-18-2020, 05:56 PM   #7
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Quote:
Originally Posted by nioh_lbbm2 View Post
If you have aggressive pops and are running high octant race fuel theres probably a good chance you melted or damaged the cat core
This right here. Burbles especially. They sound awesome and help keep the turbo spooled, but they definitely spike your EGT.
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      12-18-2020, 06:51 PM   #8
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Interested to see what your cat looks like
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      12-18-2020, 07:59 PM   #9
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Interested to see what your cat looks like
I don't think it will look as bad as yours since I still do get the pops and burbles and performance still seems somewhat fine. But I'll update a pic here if it's worthy to see.
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      12-19-2020, 01:00 PM   #10
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For what it's worth for anyone that comes across this thread,

I flashed back to stock tune recently to compare the REAL OEM burbles to BM3's supposed "oem" burble setting, and BM3's is still pretty aggressive. Don't think it'll be that safe in the long run.
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      12-19-2020, 03:11 PM   #11
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Quote:
Originally Posted by nioh_lbbm2 View Post
For what it's worth for anyone that comes across this thread,

I flashed back to stock tune recently to compare the REAL OEM burbles to BM3's supposed "oem" burble setting, and BM3's is still pretty aggressive. Don't think it'll be that safe in the long run.
Also the bmw stock map burbles feel different from the bm3 OEM burbles. The bmw stock feels more refined where as the bm3
OEM feels like a estimated copy of it.
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      12-20-2020, 10:19 AM   #12
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hmm was wondering if maybe my ignition coils are bad and can cause this issue?

I didn't realize we have to replace them that soon especially for modded and I'm around 40k miles currently.
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      12-21-2020, 01:26 PM   #13
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hmm was wondering if maybe my ignition coils are bad and can cause this issue?

I didn't realize we have to replace them that soon especially for modded and I'm around 40k miles currently.
I think it's more likely your cat. I'd pull it and take a look before starting to replace things at random. If you're replacing your coils or plugs anyway then it obv wouldn't hurt to try and see if that makes a difference, but if you're just chasing this sound issue and don't have any drivability issues start with the cat and then go from there.
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      12-21-2020, 05:39 PM   #14
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Quote:
Originally Posted by AndrewC1989 View Post
I think it's more likely your cat. I'd pull it and take a look before starting to replace things at random. If you're replacing your coils or plugs anyway then it obv wouldn't hurt to try and see if that makes a difference, but if you're just chasing this sound issue and don't have any drivability issues start with the cat and then go from there.
Agreed. Pulling your cat is also significantly easier to do rather than replacing parts.
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      12-21-2020, 10:46 PM   #15
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I am running this exact setup now. No codes.
Regarding sound. Here is a point of reference. Cold start with stock tune on 93.



FWIW, I found the burbles with the BM3 stage 2 93 tune to be too aggressive (popping all the time), even with aggression set to 1, and have since disabled them completely.

While it sounds like the DP is the issue. Is it possible your solenoid is not opening up the valves on the exhaust? They should fail open without the vacuum/tank but maybe it is a mechanical issue with the solenoid valve itself and you are stuck in a closed position.

Last edited by cpow99; 12-21-2020 at 10:46 PM.. Reason: spelling
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      12-21-2020, 10:54 PM   #16
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A very easy way to check if the downpipe is the problem is to disconnect the exhaust just after the downpipe, give it few revs and see if the sound is loud or not.
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      12-22-2020, 07:03 AM   #17
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Quote:
Originally Posted by AndrewC1989 View Post
I think it's more likely your cat. I'd pull it and take a look before starting to replace things at random. If you're replacing your coils or plugs anyway then it obv wouldn't hurt to try and see if that makes a difference, but if you're just chasing this sound issue and don't have any drivability issues start with the cat and then go from there.
Yup that's what I plan to do. Plus I always considered getting a catless downpipe since I felt the catted DP still feels somewhat restricted on sound. When I had my FI exhaust installed I expected it to be louder but it wasn't really as loud as I would have liked it. I still feel that restriction of the downpipe there even though the sound was louder.

The only issue is now for smog I would have to swap back the stock cat. Bm3 turning cat monitoring off doesn't allow smog to be passed since cat monitoring needs to be on. Or unless I get a custom tune to bypass the perimeters.
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      12-22-2020, 07:05 AM   #18
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Quote:
Originally Posted by cpow99 View Post
I am running this exact setup now. No codes.
Regarding sound. Here is a point of reference. Cold start with stock tune on 93.



FWIW, I found the burbles with the BM3 stage 2 93 tune to be too aggressive (popping all the time), even with aggression set to 1, and have since disabled them completely.

While it sounds like the DP is the issue. Is it possible your solenoid is not opening up the valves on the exhaust? They should fail open without the vacuum/tank but maybe it is a mechanical issue with the solenoid valve itself and you are stuck in a closed position.
hmm I have remote control installed and the on and off seems to work fine. I thought could be maybe the valves are not opening all the way but I don't think that's the issue.
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      12-22-2020, 10:24 AM   #19
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Quote:
Originally Posted by cpow99 View Post
I am running this exact setup now. No codes.
Regarding sound. Here is a point of reference. Cold start with stock tune on 93.


If I don't get a Remus, FI is my second choice. Great sounding exhaust.
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      12-22-2020, 01:31 PM   #20
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Originally Posted by VisualEcho View Post
If I don't get a Remus, FI is my second choice. Great sounding exhaust.
Not familiar with the Remus install but the FI does require running a vacuum line. You can see what is involved here.

FI customer service was great and would recommend.
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      12-23-2020, 01:25 AM   #21
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Quote:
Originally Posted by VisualEcho View Post
Quote:
Originally Posted by cpow99 View Post
I am running this exact setup now. No codes.
Regarding sound. Here is a point of reference. Cold start with stock tune on 93.


If I don't get a Remus, FI is my second choice. Great sounding exhaust.
I was actually considering Remus too but ultimately went with FI because you can hear the turbo spool down more and the pops and bangs are more pronounced. But can't go wrong with either one.
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      12-23-2020, 01:29 AM   #22
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Quote:
Originally Posted by cpow99 View Post
Quote:
Originally Posted by VisualEcho View Post
If I don't get a Remus, FI is my second choice. Great sounding exhaust.
Not familiar with the Remus install but the FI does require running a vacuum line. You can see what is involved here.

FI customer service was great and would recommend.
Fi can actually make an electronic valve one too but you would just have to request it. I kind of wish I gotten an electronic valve one if I had knew about it earlier but the vacuum works just fine.
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