[Bmw doubles]

Originally Posted by Hasser

stupid question but does the support bracket affect the drone / noise at all?

Nothing to do with drone. There's nothing worse when driving behind someone with a custom exhaust, they hit a bump and the exhaust tips wobble around. The bracket is OEM it just had to be cut and moved up a little to accommodate the j pipes.

[Noncom23]

Great mod. Any HP/Tq gains?

[Hasser]

Originally Posted by Bmw doubles

Nothing to do with drone. There's nothing worse when driving behind someone with a custom exhaust, they hit a bump and the exhaust tips wobble around. The bracket is OEM it just had to be cut and moved up a little to accommodate the j pipes.

Cheers, mine is currently removed.

[Bmw doubles]

Originally Posted by Noncom23

Great mod. Any HP/Tq gains?

That has not been determined yet. We're going to the dyno next week and we'll see if we can identify any gains. Maybe be difficult since here was never a baseline. I did the mod because I hated how quite it was. If I was to guess I would say stock setup no gains, tuned to take advantage of the faster exhaust gases, possibly.

[AMT92]

I just put a set of OEM M5 mufflers on and I have severe drone from 1500-2000 rpm. Does that sound right to you for OEM M5 mufflers?

Also, where did you get the J pipe done? What size piping did you use? I want to get this done ASAP.

[Bmw doubles]

Originally Posted by AMTF10

I just put a set of OEM M5 mufflers on and I have severe drone from 1500-2000 rpm. Does that sound right to you for OEM M5 mufflers?

Also, where did you get the J pipe done? What size piping did you use? I want to get this done ASAP.

Low rpm has drone sound and then cleans up at about 22-2400rpm. The trick is to get an audio analyzer, jot down the frequency that is driving you crazy then use the helm holtz equation to mathematically come up with the length of the pipe that will cancel your drone sound. I used a 2" pipe off my 3". I ended up wanting more sound so I chopped one of the end caps of the j pipe and now it's perfect, to me.

[AMT92]

Originally Posted by Bmw doubles

Low rpm has drone sound and then cleans up at about 22-2400rpm. The trick is to get an audio analyzer, jot down the frequency that is driving you crazy then use the helm holtz equation to mathematically come up with the length of the pipe that will cancel your drone sound. I used a 2" pipe off my 3". I ended up wanting more sound so I chopped one of the end caps of the j pipe and now it's perfect, to me.

What shop did the work for you for such a good price? I'm also located in LA. Work in Brentwood.

[The_M6]

Car sound great and props for the unconventional method.

[AMT92]

Originally Posted by Bmw doubles

Low rpm has drone sound and then cleans up at about 22-2400rpm. The trick is to get an audio analyzer, jot down the frequency that is driving you crazy then use the helm holtz equation to mathematically come up with the length of the pipe that will cancel your drone sound. I used a 2" pipe off my 3". I ended up wanting more sound so I chopped one of the end caps of the j pipe and now it's perfect, to me.

Also what length of pipe did you use?

[Bmw doubles]

Mikes performance muffler shop
221 W Florence Ave, Los Angeles, CA 90003

Juan is the owner and you should be able to get it done for under 200 maybe less. Bring cash.

My annoying 110hz was this equation ( 1100 / 110hz ) / 4 ) x 12 = 30 inches

This will vary for you depending on what frequency annoys you

[paul223]

This maybe a great sound mod but in long run you will have exhaust smoke stuck to car's body panels!

[AMT92]

Originally Posted by Bmw doubles

Mikes performance muffler shop
221 W Florence Ave, Los Angeles, CA 90003

Jose is the owner and you should be able to get it done for under 200 maybe less. Bring cash.

My annoying 110hz was this equation ( 1100 / 110hz ) / 4 ) x 12 = 30 inches

This will vary for you depending on what frequency annoys you

My drone is anywhere from 1400-1800 at worst depending on how hard I've driven the car. If my math is correct, I'm looking at a 42-46 inch pipe....don't know how I'm going to fit that in there.

[AMT92]

Originally Posted by Bmw doubles

Mikes performance muffler shop
221 W Florence Ave, Los Angeles, CA 90003

Jose is the owner and you should be able to get it done for under 200 maybe less. Bring cash.

My annoying 110hz was this equation ( 1100 / 110hz ) / 4 ) x 12 = 30 inches

This will vary for you depending on what frequency annoys you

Sent them a message via yelp and Emilio called me right away. Sounded very comfortable doing the job unlike my local exhaust shop. Looks like I'm headed down there tomorrow! Quoted me a good price too.

[AMT92]

Well, decided to go in today and wow, I'm dissapointed I ever wasted money at any other exhaust shop. These guys knew what they were doing, no doubt about that.

The prior owner of my mufflers had welded on a 3 inch pipe due to him having a 550. Then the last muffler shop I went to had put on 3 different pieces just to transfer the 3 inch to my 2.25!

Mike's Performance exhaust redid my piping with 1 smooth piece, re-welded the mufflers, and I got an x-pipe put on as well. The drone did not go away, so I then had them put on a 38 inch j pipe to target my peak 1800 rpm drone....and it worked!!!

Exhaust is a little bassy/drony from 1000-1500, clears up completely till 2200, then the exhaust comes to life. I'm extremely pleased with the results.

[Bmw doubles]

Originally Posted by AMTF10

Exhaust is a little bassy/drony from 1000-1500, clears up completely till 2200, then the exhaust comes to life. I'm extremely pleased with the results.

Awesome, I found my exhaust sweet spot too. They rock indeed. Glad everything worked out. What I as your final out the door cost?

I have a bass sound in that area too. Oh yeah pics!

[Bmw doubles]

Put up pics

[Bmw doubles]

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[AMT92]

Originally Posted by Bmw doubles

Awesome, I found my exhaust sweet spot too. They rock indeed. Glad everything worked out. What I as your final out the door cost?

I have a bass sound in that area too. Oh yeah pics!

$400. The M5 mufflers I purchased were installed on a 550 so they ended up hacking off all the BS mismatched piping all the way back to the cats. Had an X Pipe installed in place of the cats, solid piping to the mufflers, and two 38 inch j pipes installed. I thought it might have been a little steep but I was happy with the work.

[AMT92]

I unfortunately forgot to take more pics other than these. I'll snap some more shots later. I still dislike that 1000-1500 rpm drone. I'm wondering if I remove the permanently opened valves if it'll help.

[AMT92]

Originally Posted by Bmw doubles

Awesome, I found my exhaust sweet spot too. They rock indeed. Glad everything worked out. What I as your final out the door cost?

I have a bass sound in that area too. Oh yeah pics!

How severe is your low end drone? I have a 8AT so it automatically wants to shift to the highest gear possible...putting me in that 1300 rpm drone spot. Really don't want to have to drive in sport all the time. Wondering if these M5 mufflers just naturally have more bass. I would prefer more rasp.

[Bmw doubles]

Originally Posted by AMTF10

How severe is your low end drone? I have a 8AT so it automatically wants to shift to the highest gear possible...putting me in that 1300 rpm drone spot. Really don't want to have to drive in sport all the time. Wondering if these M5 mufflers just naturally have more bass. I would prefer more rasp.

The word rasp is subjective. I think I know what you're trying to say. I too wanted a less bassy tone. It was an evolution of my exhaust really and the final product for me was the following:

Magnaflo straight through mufflers
2 " j pipes with one closed and the other open
And a mild burble exhaust tune with my DP. Without the DP the burble tune was more aggressive, but negated by the DP.

Food for thought. Juan wanted to make me end caps for the j pipes that I could bolt on and off. Didn't go that route, but that's still on option for me. Another thought would be get the electronic exhaust valve. Juan sells them.

[AMT92]

More photos