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Exhaust Noise fix update, Daily Driver noise.

antarctica24

Active member
Messages
669
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344
Location
O'Fallon, MO, USA
#1
I purchased the MAP 2.5" with catted downpipe exhaust system for my Fist.

The MAP muffer is nothing but a large resonator. I really didn't know that until it was cut off this morning as I was waving at the exhaust guy from across the great cave in the muffler.

When I first installed it, I didn't install the downpipe right away because of the top bolt problem on the flange. You know the one that gets stripped. I know everyone says don't install the downpipe, but I wanted to anyway. I also like to play by the rules, so mine has a cat on it.

The car had a drone noise that was really noticeable above 3K under hard load all the way to 7K.

Then I installed the catted down pipe and that dropped the drone tone somewhat, but it was still there.

After speaking with Steve at Borla tech support, he suggested the 400024 XR-1 Quad muffler. It is a straight through design but attacks the noise problem through wave cancelation by the design. See Picture below.

It was installed this morning, and my drone noise is almost completely gone and is much quieter. In addition the exhaust note is lower, and in my opinion sounds better than what I had. Exhaust notes are really a personal preference thing, so I get that.

Borla%20patented%20multi-core_lrg.jpg

I paid $230.00 shipped from a company online Diesel Ops. Normal Jegs price was $247.00

I am extremely happy with the way it sounds both inside and outside of the car. If I can make a meaningful video that you can hear, I will post it.

I will be updating Steve today, and will see if there is anything I can do between the muffler and cat to reduce it more, without giving up performance, especially with the new turbo coming.

With that all said, it might have been a better move for me to have just bought the muffler setup from Borla to begin with because they use that muffler, but their system and their stuff is pricey., but I am very happy with the results.
 


dyn085

2000 Post Club
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820
Location
Vancouver
#3
This makes me glad I went with Cobb. No drone so no need for a $200+ muffler and install to task onto the base price of the system.
 


OP
antarctica24

antarctica24

Active member
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669
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344
Location
O'Fallon, MO, USA
Thread Starter #4
This makes me glad I went with Cobb. No drone so no need for a $200+ muffler and install to task onto the base price of the system.
Finally, At last, I have done and tried and slaved over everything I could do since joining this forum to make sure I made you happy. I wonder, have you made any posts that you were not being condescending or putting someone down because they did something different than you?
 


dyn085

2000 Post Club
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Location
Vancouver
#5
I'm pretty sure I said a similar thing about my Cobb RMM when you were complaining about your highly-researched Breedt RMM so I don't know why it's an issue now.

There was actually no condescension in my post, nor was I putting you down. You've commented before on how I've spent too much money on my car but now, on two separate occasions, you've shown that at least I didn't have to do it twice. And realistically, I actually don't ever even recommend that people do exactly what I've done so I don't ever have an issue with people doing things different than me.
 


Messages
87
Likes
11
Location
Boondocks
#6
I experienced the same drone from the MAP catback that you did. I took it off and sold it as I couldn't bear to deal with that on a DD.
 


Messages
331
Likes
144
Location
Gloucester, VA
#8
FWIW, the relatively inexpensive FSWerks exhaust and a CPE cat-less DP sounds great with no drone. It has a single muffler. I'm not sure why more people haven't purchased it or commented on it.
 


Messages
183
Likes
21
Location
Owings
#9
The best exhaust I've ever used has been the Corsa exhaust. In the SRT8 world, it was very difficult to find an aftermarket exhaust that did not drone with that big 6.4L. The Corsa is a true straight through design (Antartica, that doesn't look straight through to me?) that you could take a golf ball and drop it in the exhaust and it would roll all the way through.

Unfortunately, I don't think they make an application for this car, but the Cobb has accomplished the same thing, although not straight through. Really think Cobb nailed this one.

Antarctica, so that muffler is the only one on your exhaust, right. No resonators, etc?
 


Messages
183
Likes
21
Location
Owings
#10
FWIW, the relatively inexpensive FSWerks exhaust and a CPE cat-less DP sounds great with no drone. It has a single muffler. I'm not sure why more people haven't purchased it or commented on it.
I didn't even know they made one...to your point not many seem to have it. The one thing that I don't get with this one, and others, is why the heck to they not weld the tips on. Can not see a reason for clamp on tips....the less clamps the better.
 


Messages
454
Likes
123
Location
Kansas City
#11
Not to high jack but the OP mentioned the stripped top bolt on the dp to to turbo flange being a common-ish issue. I somehow stripped this bolt as well but I haven't noticed it mentioned anywhere even after searching. Is there a thread(s) here on this issue that is eluding me?
 


Messages
331
Likes
144
Location
Gloucester, VA
#12
Not to high jack but the OP mentioned the stripped top bolt on the dp to to turbo flange being a common-ish issue. I somehow stripped this bolt as well but I haven't noticed it mentioned anywhere even after searching. Is there a thread(s) here on this issue that is eluding me?
No problem with the bolt or threads really. The issue is that most folks don't have the correct tools to get a 6-point socket straight on the bolt head before cranking on it. It looks like you can get straight on with a straight extension but it isn't. I'm also guilty of using a 12-point socket at first and semi-rounding the bolt head because I was away from home living in my RV at the time. I purchased a 6-point socket and flex drive to get straight on the bolt and it came right out.
 


RAAMaudio

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Location
Carson City
#13
I had a Cobb DP and exhaust on my very modded Forester XT, it was proven to make more power and less drone than any other exhaust, it was perfect and we all know how loud Subaru engines can be.

I had thicker walled, high grade SS long tube headers, X pipe and Corsa exhaust on my C6, zero drone, sounded more exotic than any other LS I have ever heard and others that heard it loved it as much as I did.

My first setup on the ST was a full 3" DP with huge cat, the least bends and less angle of any exhaust I have seen, 5x18" Vibrant resonator, smaller Borla Race muffler, just a slight drone, deep sounding, loved it. Now I have the DHM DP with cat, same exhaust, close the same sound, not loud at all, wife approved even:)
 


Messages
454
Likes
123
Location
Kansas City
#14
No problem with the bolt or threads really. The issue is that most folks don't have the correct tools to get a 6-point socket straight on the bolt head before cranking on it. It looks like you can get straight on with a straight extension but it isn't. I'm also guilty of using a 12-point socket at first and semi-rounding the bolt head because I was away from home living in my RV at the time. I purchased a 6-point socket and flex drive to get straight on the bolt and it came right out.
I haven't "rounded off the head" of the bolt...I've stripped the threads/galled the threads/crossthreaded the bolt.
 


Messages
257
Likes
72
Location
stpaul/mpls
#15
just some info> mountune cat pipe goes in from the top easily. just remove the coolant lines and heat shield.......bob
 


Zissou

Active member
Messages
540
Likes
137
Location
Charlottesville
#16
Question for MAP exhaust guys; did you have issues with the exhaust hitting the mid chassis brace? If so, what was the solution?

Just installed my exhaust and am having that issue. Tried putting some washers in there to space it and it's still hitting it, so I pulled the brace off for now. I am not experiencing the drone issue. I have a Cobb downpipe and Cobb exhaust hangers fwiw.


Sent from my iPhone using Tapatalk
 


RAAMaudio

5000 Post Club
Messages
5,268
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925
Location
Carson City
#17
You can fix some issues with bending the hanger mounts up on the body, down on the exhaust, using a bigger set of channel locks, pipe wrench, jack, etc.....

Buying urethane transaxle and left side engine mounts or DIY for very low cost using Flexane 80 will help a great deal for that as a side effect to the main benefits of it.
 


LilPartyBox

1000 Post Club
Premium Account
Messages
1,488
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769
Location
NYC
#18
Question for MAP exhaust guys; did you have issues with the exhaust hitting the mid chassis brace? If so, what was the solution?

Just installed my exhaust and am having that issue. Tried putting some washers in there to space it and it's still hitting it, so I pulled the brace off for now. I am not experiencing the drone issue. I have a Cobb downpipe and Cobb exhaust hangers fwiw.


Sent from my iPhone using Tapatalk
My MAP doesn't tap the mid brace. Actually, I have tons of clearance. I'm on the stock DP. What I do suffer from is the mind numbing drone.
 


Zissou

Active member
Messages
540
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137
Location
Charlottesville
#19
I was able to get a little clearance by loosening the sleeves and adjusting. I ought to get it on a lift to properly do it but it's good enough for now with a couple of washers on the brace as a spacer.

Even with the pipe touching the brace I didn't get any drone. I'll monitor it the next time I'm on the highway. It's certainly much louder at 3-4K rpm when I'm getting on it, but part of that is the sound symposer and part of it is that I'm getting on it. Cobb downpipe for me, which gives it some BA burbles and pops that I didn't have when I had the Cobb DP + stock CBE. Maybe the more open downpipe reduces drone? Seems like it would be the opposite but who knows


Sent from my iPhone using Tapatalk
 


MPA

Member
Messages
332
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84
Location
STL
#20
No clearance or drone issues here. - I just did a 1500 mile trip, and it would've driven me crazy since I was cruising at 80mph 90% of the ride. Love my MAP exhaust
 




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