DieL

Hey all. Basically wanted to toss the question up, does anyone else think the 3" B&B mufflers in particular may actually be a restriction ? Reason I think so is with longtubes, x -pipe and straight through the mufflers, My car isn't very loud. Granted it is a very small cam in the 388, and is noticeable.. but the sound really has me thinking that these mufflers just look good.. but suck horribly.

ANyhow, since I removed my random tech cats I've been searching for other ways to reduce the dreaded resonance. So far, I have 2 14" long 3" straight through resonators w/sound deadener inside. I'm going to be cutting the B&B pipes behind the x-pipe and adding them in there.
As for the front where the cats were, Im getting 2 9" long race mufflers, that are actually the same as the resonators being straight-through with perforated holes and sound deadening. So with 4 resonators in the system I'm hoping the resonance may be reduced somewhat.

The other thing that had me thinking about the mufflers being a restriction was the Zr-1 owner, Mike (i think.. so sorry) with the 415 LT5. he said he removed the b&b mufflers and gained like 30 hp from it. granted it is making 590 rwhp on a dynojet, but mine is now making 478 rwhp on a mustang dyno and does rev to 7850 rpms.

Exhaust is going on Monday. I plan on making sound clips to see if there's a difference. Till then..

95wht6spd

The extra mufflers will help cut out a lot of resonance, I did the same. I wouldn't think the mufflers would restrict more than just a few HP.

ElisTwoCents

What have you done to the car...? I have 3in B&Bs waiting to go on. There is no way in hell my Borlas outflow the B&Bs. I too have longtubes, no cats and just the mufflers and it isnt loud.

As for 415 LT5 I dont think there is a muffler he wont loose a lil power

BlackC6LS3

I havn't gotten to do any testing with the longtubes and BB on my car but I doubt it robs much power. My system came with a resonator and there is only a slight amount of resonance at the usual rpm, but with the auto and 4.10's, i'm never in that range. Hoping others share their thoughts and experiences.

Idburnu

I don't know if they are a restriction in general, but I don't find them to be that loud either in comparison to say a 2 chamber Flowmaster or something of that nature. Barring the whole resonance debate, I think they are fairly mild. Good tone, but not deafening by any stretch.

On your car with the power you are making and the RPM you are turning, they probably will be a restriction but not anymore than any other "performance" muffler I wouldn't think. You might free up some going to a true race muffler, like a single chamber FM, but the hassle you will get from law enforcement probably isn't going to be worth it.

If you do any dyno test, I would be really interested to see how much if any power they are robbing and how they stack up to another brand in "real world" testing.

DieL

Anyone ever cut apart a B&B muffler? Looking in it from the tips, and knowing its the 'latest' lower resonance version, i can see the flow from the inlet splits off and has a bunch of angles to go around, kind of like corners. From what i know the more the flow has to turn the more it harms the speed of the flow. based on that I was guessing this is where the resonance is coming from.

Its by no means unbearable. I don't think the added resonators and mufflers will be any sort of a restriction because they are 3" straight through. I was going to go with the Random tech cats but I could care less about emissions. I would have been re-buying 2 expensive cats from them just to reduce the resonance and figured I would be better off spending half that on some nice T-304 resonators that will also make my sound a little more unique. As for replacing the mufflers I just wont. i don't think theres a better looking muffler out there for these cars that is in a 3 " size. I may take apart the mufflers over the winter and do some modifications. It is a long winter and I have to do something to keep my mind occupied

I might go out for a boot tonight and take along my digi cam on my cross bar and record some sound clips. if I do I'll post em up

DieL

I hear you on the rpms. When I had bolt ons with no cats stock exhaust after longtubes i also had 4.09 gears. I had never heard of resonace before. i was clueless for 7 years why everyone was complaining about it. Resonance is the only reason I regret going down to 3.73s. Otherwise they are much better highway gear for my motor (for me anyways - love the looong pulls)

kpforce1

I have the B&B 3" system on my car with an X-pipe in place of the B&B resonator. I have a 480hp LS1 in my C4 with some big long tube headers and I was VERY suprised at how quiet the car is at idle. Very stealthy (except for the lope). At WOT it gets pretty loud though and I can spin the tires in the first 4 gears.... lol I don't think there is a restriction.... I also think the X-pipe is helping keep it quieter

vader86

if youre making power numbers that high, i wouldnt be surprised to find out a big power difference between no mufflers and any mufflers

SurfnSun

The only ones that might keep up would be the Ultra Flow welded mufflers that flow better than 2k CFM each.

DieL

What really makes me wonder is the COrsa is a 2.5 inch straight through muffler. The B&B is a 3" but the flow isn't straight through, it has to push around corners and walls.

DieL

I ended up buying 2 race mufflers, basically straight through design 3" with perforated holes and sound deadening in them. those will go where the cats were. In the back of the system after the x-pipe I bought 2 16" long resonators with the same straight-through design and perforated holes with sound deadening in them. If anything it should quiet it down a bit and not be a restriction. it's going in on monday morning so I'll take some sound clips for sure for a before/after. I wanted to last night but couldn't find the bolts for the camera mount

ElisTwoCents

What mods do you have?