B&B or OE with premuffler on 3.2?

[Thrasher]

I have two exhausts in my garage for my '84 3.2 coupe

The first is an OE system, but from an '83 3.0 SC. I just finished re-reading the section in the '911 Performance Handbook' by Bruce Anderson. He clearly states that the tubing was enlarged for the 3.2 from the 3.0, although he doesn't say by how much.

This SC exhaust was put on by the PO to meet emissions just prior to selling me the car last June. I have since replaced the cat with a stainless euro premuffler so I could easily do emissions testing every other year. I was also planning on adding a second "bull horn" on the right side for a little better sound, followed by a Steve W chip to match all of this.

That exhaust replaced the B&B stainless headers/muffler that is the second one in my garage now. The PO had removed it and left it in storage. I just picked it up and it's in very, very nice condition.

Bearing in mind that I use the car for "fun" driving and a DE or two a year - what would you do with that B &B - sell it and put the money into other things on the car, or mount it up?

[Por_sha911]

I get a lot of positive comments on the sound of my B&B's. As you already know, the larger pipes will affect low end torque so I added a Steve Wong chip specifically set up for my setup with the B&B's. For fun driving I say keep them.

[Thrasher]

Do you by any chance have a sound clip of B&B's on a 3.2? Their site only has 996 and Boxster clips.

So, you're saying that the larger pipes will negatively impact low-end torque with the OE chip, but the SW chip corrects for this?

What I had read was smaller headers would be better (HP and torque) on street-driven cars (lower rev range usually), but worse on the track (higher rev ranges) and larger header pipes would behave just the opposite.

Can I have the best of both worlds just by re-chipping?

[Thrasher]

bump... because I would really like 1/10 of one percent as many responses as the keychain thread ;-)

Thanks,

Craig

[Jim Garfield]

Well, I'm in the minority of people who have had good luck ( so far ) with both B&B headers and muffler. I have a 3.2 dual in /dual out setup with HE that the previous owner installed. I am too cheap to have spent the $2500 that the PO did for this system and in that vein I'm going to use it till it breaks.

I suspect that the muffler is a later unit and that B&B altered the design to address the split seam problem. Mine has gussetts welded in where most of the early ones seem to split. The dual out doesn't really add much hp and if I was going to buy a muffler it would be the single outlet. The dual sounds great but has an annoying resonance between 2- 3k. I have found a way to get rid of it but, B&B should have done the R&D on this, not me.

If you do a search on B&B you will find many disatisfied customers, and frankly if I had bought this setup and the muffler blew out I'd be upset too.
I can only tell you that mine has been fine, I'm quite picky, and I would say that the quality of the fabrication looks good imo.

I do plan on a Steve W. chip in the near future and I would be very curious to see the dyno #s on a setup like mine, I suspect that it's making pretty good hp, based on a few um, "impromptu tests"...

As far as emissions, with no cat I passed the last two sniffer up the exhaust pipes, roller tests with flying colors.

[Wavey]

Originally posted by Thrasher
Can I have the best of both worlds just by re-chipping?

Yes.

Give me a call Craig and you can drive mine if you want to see what the Steve Wong chip does.

[Bill Verburg]

B&B headers are fine, as has been mentioned the mufflers have suffered from a variety of faults. Early ones blew out packing, resonated and cracked repeatedly, later ones w/ the reinforcing gussets are much better and are almost single out anyway, take the passenger side tip off and you will see the tiny exit on that side. Take a picture for posterity. The B&B mufflers w/ gusset and small passenger side exit are unlikely to suffer the same resonance issues as earlier versions(unless the packing blows out) They do sound good when working right.

[Bill Verburg]

Here's a set of late B&B headers and muffler w/ the gussets

[fireant911]

I agree with Bill, the heat exhangers/headers are fine and well contructed. Apparently, I had one of the earlier mufflers and it was complete trash - resonanting and obnoxiously loud with several cracks to boot. A small decrease in performance was noted when switching back to OE exhaust but never a moment of regret.

[Thrasher]

Thanks for the input guys.

Wavey, I may take you up on that offer. Is your chip specifically set up for SSI's and Dansk Sport muffler?

Bill, where in the picture is the gusseting you're referring to? Is it where the collector pipes enter the muffler?

My muffler is also without cracks/flaws. I have the single-out version, but have never mounted it up and heard it in action. I'm tempted to try it now. I guess the only thing I'd have to mod is the 02 sensor wires that won't reach the bung without putting an extension on.

Anybody have any dyno results for a B&B on a 3.2?

[KTL]

Here's a flashier (sorry Bill) picture of the reinforced B&B muffler



Thrasher,

Send me a PM with your email address and i'll mail you a sound/video clip of the 3.2 starting up with B&B headers and dual out muffler. Unfortunately I don't have a clip of the car on the road. It sounded pretty sweet above 4000.

You don't need the O2 extension. There's plenty of wire on the O2 sensor. What you can do is cut the rubber grommet open and move it to a different location on the wires.

Jim,

What did you do to reduce the resonance on your setup? Smaller outlet pipes? I agree the 2-3K rpm resonance is awful with the B&B dual out on their headers.

[Wavey]

Originally posted by Thrasher
[B]Thanks for the input guys.

Wavey, I may take you up on that offer. Is your chip specifically set up for SSI's and Dansk Sport muffler?/B]

Nope, standard heat exchangers, Dansk premuffler and Dansk single-out Sport. But the chip did more than anything to improve performance. If you've driven a Carrera with a standard chip, the difference will be obvious. Let me know if you want to hook up some time - I'm frequently in St. Louis on business.

[Thrasher]

KTL: sent you a pm/email - thanks. I don't have that gusset on my muffler, but no cracking either. I recently replaced my 02 sensor with a universal one, and when I spliced the wires, I trimmed them to remove any excess (d'oh!). So, I'd have to extend them to reach. Not a major project, though.

Wavey - even better. I also have the premuffler on my stock exhaust setup, but not the sport muffler. The chip on my '84 is mapped much more conservatively than your '88 had from the factory. I think I'd really benefit from it.

Craig

Craig

[Jim Garfield]

Originally posted by KTL Jim, What did you do to reduce the resonance on your setup? Smaller outlet pipes? I agree the 2-3K rpm resonance is awful with the B&B dual out on their headers. [/B]

Kevin, first I tried reducing the size of the right side muffler exit, which helped quite a bit, but seemed a little half assed. I'm now having two exhaust pipes made up that reduce the size from 3" to 2.25". Jack O has recommended this mod and claims that it cured the resonance problem.

[KTL]

Jim,

I recall Jack saying the same thing. Thanks for the confirmation.

[Bill Verburg]

Here's a flashier (sorry Bill) picture of the reinforced B&B muffler

No problem I always meant to take better pics but never got around to it.