Muffler Delete

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Hey everyone,

So over this past weekend I went to a muffler shop to do a muffler delete. I have already the BMS 3" catless downpipes installed and I wanted a bit more, "grumble." In the picture below is the post-muffler delete. After I had it done I noticed in the low rpms in 2nd gear my car was feeling, choked. As if I was getting lag down low. At first I thought it was due to the loss of back pressure but that only negatively impacts naturally aspirated cars so I am a bit confused, if anything it should be more free flow. Anyways, this muffler delete also gave me an excessive amount of drone! It is extremely obnoxious and I am very surprised by it.

Any solutions anyone can recommend? Also, is there anything you notice about the picture? Some have said the pipe they used seems to be a smaller diameter than the stock pipe. I was thinking about removing the secondary cats, leaving the resonator and placing an aftermarket muffler on, (magnaflow?)

Any suggestions/help would be greatly appreciated

[ShocknAwe]

Looks like it was crush bent, which is going to give you more restriction than mandrel bends. It doesn't look very well made to be honest.

Suggestions:

Have it redone, all mandrel bent.
Try to make piping as straight as possible, minimal bending.
You could remove secondary cats and replace with additional resonators.
If you are going to add a muffler, I would recommend a 2 in 2 out and actually keep the piping separate.

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Originally Posted by ShocknAwe

Looks like it was crush bent, which is going to give you more restriction than mandrel bends. It doesn't look very well made to be honest.

I appreciate the honesty, everyone agreed that the job was not done well. Are there any alternatives? Or anyway I can have them adjust it?

[ShocknAwe]

Originally Posted by DurimOne54

I appreciate the honesty, everyone agreed that the job was not done well. Are there any alternatives? Or anyway I can have them adjust it?

I added a few comments to my previous post. Hope it helps!

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Originally Posted by ShocknAwe

I added a few comments to my previous post. Hope it helps!

Just saw it thank you!

As an alternative would you suggest just waiting for an axle back?

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Video of my cold start up

[c_ozanich]

Originally Posted by DurimOne54

Just saw it thank you!

As an alternative would you suggest just waiting for an axle back?

price wise an axle back is going to be more expensive. That's your call but also gives you the opportunity to hear it via youtube before buying so you know what it will sound like

otherwise follow Shocknawe's write up

**removing secondary cats and getting resonators is the way I would go personally.

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Originally Posted by c_ozanich

price wise an axle back is going to be more expensive. That's your call but also gives you the opportunity to hear it via youtube before buying so you know what it will sound like

otherwise follow Shocknawe's write up

**removing secondary cats and getting resonators is the way I would go personally.

Is it true removing cats decreases drone?

[RimasRS]

To me it looks that shop did a shit job... Sorry.
Put magnaflow on. And if you delete secondary cats insert resonators instead of them. Because you will have tons of drone.

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Originally Posted by RimasRS

To me it looks that shop did a shit job... Sorry.
Put magnaflow on. And if you delete secondary cats insert resonators instead of them. Because you will have tons of drone.

No need to apologize I'd rather the honesty.

Can't possibly have anymore drone than I do now, and this is my 4th car with an aftermarket/modified exhaust.

[Marc08EX]

I'm not an exhaust expert because I haven't tried all the exhaust variations on the 135i.

Since you want to eliminate as much of the muffler as possible, why not get the aFe axle-back exhaust? IMO, this has the smallest silencer built in the system. Just a suggestion.

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Originally Posted by Marc08EX

I'm not an exhaust expert because I haven't tried all the exhaust variations on the 135i.

Since you want to eliminate as much of the muffler as possible, why not get the aFe axle-back exhaust? IMO, this has the smallest silencer built in the system. Just a suggestion.

Because it's a more expensive alternative haha. But I regret not doing an axle back in the first place.

[RimasRS]

Originally Posted by DurimOne54

No need to apologize I'd rather the honesty.

Can't possibly have anymore drone than I do now, and this is my 4th car with an aftermarket/modified exhaust.

If you will delete cats you will see that it is possible. You need to add as big as possible free flow muffler and resonators to make the sound deeper.

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Originally Posted by RimasRS

If you will delete cats you will see that it is possible. You need to add as big as possible free flow muffler and resonators to make the sound deeper.

Might be the best solution. Magnaflow muffler and vibrant resonators in replace of the secondary cats. What about the stock resonator I have on now?

[RimasRS]

Originally Posted by DurimOne54

Might be the best solution. Magnaflow muffler and vibrant resonators in replace of the secondary cats. What about the stock resonator I have on now?

better to leave it in place because it doesnt have any restrictions you can see here what is inside of it http://www.1addicts.com/forums/showt...php?p=13129956

And I believe its helping to eliminate drone also. Everything you want to remove is 4 cats and put free flow rear muffler for better performance. But to keep deeper sound you need big resonators or muffler.

[Marc08EX]

Originally Posted by RimasRS

better to leave it in place because it doesnt have any restrictions you can see here what is inside of it http://www.1addicts.com/forums/showt...php?p=13129956

And I believe its helping to eliminate drone also. Everything you want to remove is 4 cats and put free flow rear muffler for better performance. But to keep deeper sound you need big resonators or muffler.

It's because the posted in your link has a 1M. AFAIK, the 1M resonator is pretty much a straight pipe with the resonator housing only. The 135i resonator functions like a normal resonator.

[RimasRS]

Originally Posted by Marc08EX

It's because the posted in your link has a 1M. AFAIK, the 1M resonator is pretty much a straight pipe with the resonator housing only. The 135i resonator functions like a normal resonator.

Yes but N54 resonator looks the same just the pipe inside is perforated.

[c_ozanich]

Originally Posted by DurimOne54

Is it true removing cats decreases drone?

it depends on what you replace them with. resonators give you a deeper tone, straight pipe gives you in credible loudness and drone, and high flow cats maintain more back pressure so you get a little more crackle in the exhaust.

I have Berk mids (I know its not the route you're looking at) but they are the best sounding mod I could have done. My N55 doesn't have the cats a N54 does but my downpipe was too loud for my taste with my stock mids. The resonators and slightly bigger piping quieted the beast down)

My last car I built had a high flow cat into dual resonators and into an off the shelf catback exhaust--it sounded deep and rich. For what you are going for, at least what it sounds like, get the vibrance resonators and see how you like it. Then get a magnaflow if you feel there's still too much drone. Doing the exhaust in pieces like that will give you a better understanding of what each section/part specifically does for the sound quality.

[c_ozanich]

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Originally Posted by c_ozanich

That's the plan!

Thank you for taking the time out to make this.

[c_ozanich]

Originally Posted by DurimOne54

That's the plan!

Thank you for taking the time out to make this.

no problem! make sure you get a video of improvement posted in here!

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Originally Posted by c_ozanich

no problem! make sure you get a video of improvement posted in here!

You got it