B&B Exhaust - Need to lower noise levels in cabin

[Thrasher]

Jim or Kevin: A picture is worth 1,000 words and a soundclip or video about a million!

[Jim Garfield]

We are in the middle of a 50mph rain deluge right now. I'll try to get a photo when I can.

[Kevin Stewart]

I had the muffler shop cut the tail pipe off at the muffler he then bent some 2 or 2.5 pipe to match the old tail pipes, i had found a couple tips that look like small 993 tips and put them on, it really is amazing the dand thing sounds like an indy car and its half as loud, ill try and find a picture, are you kidding me on a sound bit it fricking 15 degrees out side Kevin

[Thrasher]

@Jim: Thanks... no hurry. That's the weather we had over the weekend.

@Kevin: I hear ya. My cover hasn't come off in weeks, either. Sounds like you're further North than me! (your location doesn't show in your profile)

I'm just looking for a Winter project that I can unbolt and bring indoors!

[Kevin Stewart]

Thrasher i am just across town from notre dame

on the tip all i can say is try you will be amazed, i am extremely happy, the 4 inch b&b tips set off car alarms, the new set is awesome, Kevin

[Pierre911SC]

Hello Gents,

Very interesting thread.
Here is one solution that I like, for a dual out 3in. BB.
Take one of theses 2.5in. X 7in. flared ends
to fit into the 3in. BB, and slip in the assembly between muffler and end pipe.
Sound easy, will let you know if it's working...That's going to be next spring,
the car is in hibernation.

Regards

[Thrasher]

Pierre, where did you read about this (or is this your own idea)?

I have the single-out B&B muffler with B&B Headers - are you suggesting to choke down the header out/muffler in connection or to insert this choke at the muffler exhaust outlet(s)?

If you have a link or pictures to anyone who's done this it would be helpful.

Thanks,

Craig

[Pierre911SC]

Hello Craig,

I learned from page one of this thread, EMJ, Thrasher, Jim Garfield,
and implemented Thrasher idea, NO glory for me.
Yes, theses custom fabbed at an exhaust shop ($40.), and they do fit
between muffler end exhaust tip at the bumper.
Hope that this will reduce the ratteling drone between 2-3K rpm.

Regards

[Thrasher]

Resurrecting this thread since I'm still living with the drone. I saw references on other auto boards (Viper, Corvette) to the Dynatech Vortex Cone - has anyone had any experience with these with B&B Billy Boat mufflers and/or headers?

I searched the archives for "vertex + cone" and found this, but it's not specific to B&B drone issues.

[cubby911T]

I had a similar problem on my 964 - tooth rattling drone at 2600-3000 rpm. It's because the PO deleted both mufflers and instead just had 993 heat exchangers feeding into a twin cat with tailpipes coming directly out of the cat. LOUD!!!! rather than putting the stock exhaust back on (PITA) or having a muffler fabricated to replace the cat and mate-up to the 993 heat exchangers, I tried a little product called CC Inserts. I just inserted them into the tailpipes (not ideal, but effective) and it took just enough of the edge off to make the car comfortable to drive. Still loud and still a little drone but MUCH better. You can buy them at Car Chemistry : The Science of Performance and there is a nice thread on another discussion board that a guy shares his experience: CC Insert for reducing exhaust drone....wow it works! - AcuraZine Community

[Thrasher]

Interesting. I think I could actually benefit from a little back pressure. I've heard several knowledgable folks on this board comment that the B&B's for 3.2 are actually a tad oversized for stock cams.

I felt a drop in low-end grunt when I put the B&B headers on, presumably at the benefit of WOT/redline flow. Since mine is a primarily street-driven car, I'd rather have it the other way around.

[ALXinNZ]

I have a similar problem with my twin out for my 3.2. Except it isn't me that worries about it. I love the sound but my better half finds it unbearable at 2500-3000 rpm.

So I made one of these for the back. using some 2mm plate a spring and some split pins. It is closed till about 3500 and opens when and as required






Please dont hold it against me for using a brake piston pad for the cap. I know it is a bit rough, Surprisingly it works great, The only down side is the Motronic finds it hard to adjust. When I remove the cap it hunts and idles rough until it learns the new set up. ( for lack of better words) this is also a concern as I do not want to run it lean so I will be putting on a dyno soon to see the difference on and off.

[Pierre911SC]

Hello Gents,

Just to follow up with the results of the inserts. Yes, they do reduce the noize
and a bit of the drone. But, still loud for me.
I plan to explore with different inserts lenth, and diameter.

Regards

[Joe Bob]

Weld Super Trapp ends on it....you can tune the sound by adding or deleting discs.

[Busta Rib]

I had a dual-out M&K GT3-style exhaust and the drone was unacceptable between 2-3K RPM. I swapped it out for a 1-out and the droning went away, but it still sounds sporty/throaty. I can live with a louder exhaust, but not the droning.

Based on what I have read in other threads, almost all 2-out exhausts will drone and the only sure-fire solution is going to a 1-out. Barring capping one of the outlets/reducing the diameter, you can try futzing with the internal baffles to create a different resonance profile. But that requires a shop cutting open the exhaust and experimenting. Good luck.

[EMJ]

So I'm finally getting this 2500RPM drone in 5th gear problem fixed! As has been suggested in this thread, reducing the tail pipe diameter from 3" to 2.5" in my B&B exhaust should solve the problem. Spoke to a couple of shops, finally found one that is very familiar with the problem.

Been doing some searches on 2.5" tail pipes to purchase - can anyone suggest some resources for me to check? I plan to buy the tail pipes and have them shaped to my current configuration for installation.

Thanks!

[Quicksilver]

Easy solution to a 2500 RPM drone...

Don't let it drop to 2500. (Seriously! Keep it above 2800-3000 RPM...)

[Jack Olsen]

I've been down this road. First I had the B&B muffler. Terrible drone and too loud. I reduced the tips down to 2.5 (or 2.25) and that improved things very slightly.



Then I went to a Flowmaster (the B&B was cracking), and the solution for drone there was to cap one outlet. I used a Campbell's soup can with the end painted black. On track or fun run days, I'd just undo the hose clamp that held it on the exhaust.



Soup can:



Then I went to a Magnaflow muffler. No drone at any RPMs. I with I hadn't wasted my time with anything else. Mine might be slightly quieter because at the same time I switched to the 993 short headers from the B&B. But the Magnaflow seems to be MUCH better than the B&B or the Flowmaster. And I'm pretty sure it's the cheapest of the bunch, too.



Sounds SWEET.

[Thrasher]

A while back, I finally had a 2.5 inch outlet for my B&B single out fabricated. I was amazed at the difference inside the cabin. The drone is completely gone. I'm still not 100% sold on my B&B setup. My car is a street driver that has been to the track once so far, so realistically, comfort over performance is my goal. The heat from my B&B headers is also weak, and I'd like to backdate the ductwork in my engine compartment, but doing so would mean even less heat. I'll stick with this setup for now, but may dump the whole B&B setup at some point, despite the lack of drone.

[EMJ]

Originally Posted by Jack Olsen

I've been down this road. First I had the B&B muffler. Terrible drone and too loud. I reduced the tips down to 2.5 (or 2.25) and that improved things very slightly.



Then I went to a Flowmaster (the B&B was cracking), and the solution for drone there was to cap one outlet. I used a Campbell's soup can with the end painted black. On track or fun run days, I'd just undo the hose clamp that held it on the exhaust.



Soup can:



Then I went to a Magnaflow muffler. No drone at any RPMs. I with I hadn't wasted my time with anything else. Mine might be slightly quieter because at the same time I switched to the 993 short headers from the B&B. But the Magnaflow seems to be MUCH better than the B&B or the Flowmaster. And I'm pretty sure it's the cheapest of the bunch, too.



Sounds SWEET.

Thanks, Jack. A soup can with a hose clamp? That's ingenius. Painted black? Have to say, it even looks cool. I think I'll try this tonight and see how it goes. Simply ingenius!

My drone actually isn't that bad so this may just fix it!