[FenixMike]

Once I figure out what exhaust I want to build im gonna have to get that... looks much better!

[Jayphil]

Thanks all for the comments. I ordered 2 Vibrant 1792 bottle style resonator that I will put in the mid pipe to reduce cold start noise and hopefully some of the drone otherwise I really enjoy the exhaust most of the time.

If the resonators does not cut enough drone for me I might try 1/4 wavelength resonators (branch resonators) to cut the drone).

[Jayphil]

I have still not receive the resonators but I did some measurement / calculation to prepare my self for 1/4 resonators if the vibrant resonator does not help enough.

Based on my calculation

at 1900 RPM
3 pulse/REV for a I6
Speed of sound of 343 m/s

The drone frequency should be at 95HZ and require 35,5" of 1/4 resonator piping.

I have used Iphone RTA application (ETANI) and my real life highway measurement was that the 95HZ-100HZ frequency was the peak in DCB (73dcb) which is about 10-12 dcb highier than the other peak frequencies so that is confirming my calculation were correct.

I am eager to see if the vibrant resonator will reduce the dcb of the 95hz-100hz frequency enough for me or if I will need the 1/4 wave.

For those who are wondering 10dcb increase is perceive by human of between twice as loud. (Physics say 3dcb = twice the energy but human does not perceive it that way).

Hopefully I will be able to reduce the 95hz-100hz frequency by 10dcb to cut by half the perceived loudness of the drone.

[Aiden.Detailing]

n e one have a underside pic of the install on this exhaust?

[Jayphil]

Originally Posted by Aiden.Detailing

n e one have a underside pic of the install on this exhaust?

I have received my resonators and have an appointment this Friday for the installation. I will try to snap some pictures at that time but nothing special / sexy about this setup.

ER Downpipe, stock piping, stock resonator, vibrant resonator, Megan mufflers.

The 1/4 wave resonator is my last option. First I am trying the resonators and will add sound deadening material in the trunk if drone still bother me.

[Aiden.Detailing]

lets us know how the sound compares to stock?

[lsturbointeg]

Originally Posted by Aiden.Detailing

lets us know how the sound compares to stock?

+1!

[bin01123]

All of the vehicles look clean guys. Kudos!!!!!!

[mike@x-ph.com]

Originally Posted by Aiden.Detailing

lets us know how the sound compares to stock?

Interested in the outcome as well

[AMT92]

Originally Posted by Jayphil

I have received my resonators and have an appointment this Friday for the installation. I will try to snap some pictures at that time but nothing special / sexy about this setup.

ER Downpipe, stock piping, stock resonator, vibrant resonator, Megan mufflers.

The 1/4 wave resonator is my last option. First I am trying the resonators and will add sound deadening material in the trunk if drone still bother me.

What ever happened with this? How do the megans sound with the vibrant resonator? Drone? Aggressiveness?

[Jayphil]

Originally Posted by AMTF10

What ever happened with this? How do the megans sound with the vibrant resonator? Drone? Aggressiveness?

I never happen to install the 1/4 length resonators but might do it next summer. The setup is a bit loud at startup for 15s but after that it is quiet. Driving in sport mode sounds nice with reasonable drone. Fast acceleration is nice and not too loud inside and out. Deceleration sound very good with some burbling. Do not expect very deep / exotic sound but still sound 100 times better than stock. The vibrant resonator helped to clean the sound and reduced the drone until 70mph. The only downside is drone in confort mode and above 70 mph. I got use to it but I still feel it is out of place for a luxury car so still want to try the 1/4 length...

[The_M6]

I get drone on mine anytime I'm under 2000 rpm's. Interesting you only get it at highway speeds. Is it because you're constantly shifting around town and cruising speed induces the drone because of the lower rpms?

I have a 550i M Sport so I know it's a different beast altogether but interesting the characteristics are so different between the I6 and the V8.

[AMT92]

I have a set of J pipes (quarter length resonators) on my exhaust setup and there's minimal to no drone. Definitely worth trying out, just make sure you get the right length and the shop is competent enough to create them.

[maxximus]

good work! ..wish i could find a deal on some pipes at that price :/

[Jayphil]

Originally Posted by Blu550

I get drone on mine anytime I'm under 2000 rpm's. Interesting you only get it at highway speeds. Is it because you're constantly shifting around town and cruising speed induces the drone because of the lower rpms?

I have a 550i M Sport so I know it's a different beast altogether but interesting the characteristics are so different between the I6 and the V8.

I get some drone in town but mostly in confort mode when rpm is below 2500 RPM. The car in sport mode keep rpm highier and most of the time off drone zone. I would say for my car there is two drone zone, first in comfort when RPM is too low (aournd 1.5 rpm) and around 1900 to 2200 rpm(65mph and above). On highway 55 mph to around 65mph the drone is very mild unless you are climbing a big hill and the car decide not to shift to get more power.

[The_M6]

Originally Posted by Jayphil

I get some drone in town but mostly in confort mode when rpm is below 2500 RPM. The car in sport mode keep rpm highier and most of the time off drone zone. I would say for my car there is two drone zone, first in comfort when RPM is too low (aournd 1.5 rpm) and around 1900 to 2200 rpm(65mph and above). On highway 55 mph to around 65mph the drone is very mild unless you are climbing a big hill and the car decide not to shift to get more power.

About the same as what I see. With an 8 speed transmission I find I'm almost never in 8th gear even on the highway unless I'm above 80mph which is rare because I don't commute for work.

[EL Jeffe 5]

Nice work, Looks amazing.
Thanks for posting

[Jayphil]

I just want to add that the black "ceramic" paint that I have put on the muffler cans still hold-up and this make at big difference in making my car look like more like if it was like this from factory. The color matched diffuser also add to the OEM look.

[Ickdeep]

Originally Posted by Jayphil

I just want to add that the black "ceramic" paint that I have put on the muffler cans still hold-up and this make at big difference in making my car look like more like if it was like this from factory. The color matched diffuser also add to the OEM look.

Where did you get that diffuser? I've been thinking about doing the Dual tip mufflers and upgrading the diffuser.

[Jayphil]

Originally Posted by Ickdeep

Where did you get that diffuser? I've been thinking about doing the Dual tip mufflers and upgrading the diffuser.

As stated on my first post, it is an OEM M5 diffuser that I bought new from a BMW dealer that does online sales. You need the adaptor to fit. It was 226$ from getbmwparts when I purchased it.

Of course you will have to get it painted which is not that expensive.

[Ickdeep]

Originally Posted by Jayphil

As stated on my first post, it is an OEM M5 diffuser that I bought new from a BMW dealer that does online sales. You need the adaptor to fit. It was 226$ from getbmwparts when I purchased it.

Of course you will have to get it painted which is not that expensive.

How much was the adapter? And from where?

Thank you for the help

[Jayphil]

Originally Posted by Ickdeep

How much was the adapter? And from where?

Thank you for the help

Same place as the diffuse and included in the price I gave you.