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Posted by: mb911 Jul 11 2017, 08:21 AM

As many of you know I started ,designed, owned M&K exhaust and sold it now about 6 years ago. The new owner and I have been discussing the need for a quiet good flowing muffler that is stainless and of the highest quality. So I decided to design a new muffler that mimics the original design and something that could be marketable. After much analysis of the stock muffler this is what I came up with. I will be offering a group buy in the near future on these mufflers. Please note these will be single out let only and I will still need to do some testing. I may offer a few good deals for those willing to test the completed mufflers.

Please note these are completely my design and will be sold with the m&b specialties name but others will carry the product like m&k..

Posted by: arne Jul 11 2017, 09:01 AM

Ben, if these will be offered in single inlet as well as 2-in, I'd be interested in one for my 3.2 Carrera. The current offerings are either too loud for my taste, or less than acceptable build quality.

Posted by: mepstein Jul 11 2017, 09:05 AM

I think the 911 crowd is going to go nuts for these.

Posted by: Cairo94507 Jul 11 2017, 09:11 AM

If this will mate perfectly to your larger Six heat exchangers....I see the complete set-up in my future. What a great product line.

Posted by: mb911 Jul 11 2017, 09:25 AM

These will be only 2 in 1 outs everything else you should go with other options like m&k ( I get no reimbursement saying that) etc. And yes a package would be perfect. I actually have a set of 1.5" heat exchangers 80 percent done that are not spoken for. If someone wants a deal ..

Posted by: arne Jul 11 2017, 09:48 AM

I thought that would probably be the case, looking at the internal design. Not so good for me, then. But I've got a friend locally with a '73.5 T who could use something like this to replace his rusty Bursch. Will be watching for this in the future.

Posted by: JmuRiz Jul 11 2017, 10:07 AM

Very cool, the hits just keep coming from you eh?

If I didn't already have an old M&K sport muffler I planned on sending to you for upgrades (rally style 3rd pipe and caps for the centers), I'd totally get one.

I'm getting old, have neighbors REALLY close to my house and a young child, so a lower volume would be great!

PS: I really wish I lived closer...you could design a custom exhaust for my Audi C5 S6 wagon

Posted by: mb911 Jul 11 2017, 11:40 AM

I should have something ready by the end of the week with pricing.

Posted by: Chris914n6 Jul 11 2017, 12:56 PM

Interesting. I just started looking into a 2in1out that won't choke 300hp. I like quiet, hate drone, and love the sound of the stock 1in1out banana currently on my 3.0.

Posted by: gereed75 Jul 11 2017, 01:14 PM

Been looking also. Your design looks similar to the classic mods recommended on the stock banana as you well know.

Will be very interested in doing a Beta for you on my 2.4 Mod Solex Weber carbbed six hot rod

Want something with a bit more sex than my stock banana. Boy that sounds perverted !!

Will be running in a PCA track event on August 4. That would get you some exposure for a good public test.

Posted by: 914_teener Jul 11 2017, 01:14 PM

Am I the only one interested in a dual for a type IV that will mimic a triad but a tad quieter?

Posted by: bandjoey Jul 11 2017, 01:22 PM

Type IV depending if it sounds good, not too loud, and csob priced. Keep us posted.

Posted by: mb911 Jul 11 2017, 01:45 PM

I am bound by non compete clause that I can only do 1 design. So inlets are the only thing that I can change..

Type 4 would be the only option besides 2 in..

Posted by: 914_teener Jul 11 2017, 02:11 PM

Understood....

Meaning single out I.d assume.

I.m not necessarily a csob but for a type IV a reasonable price would be ok.

Thanks for putting a feeler out there.

Posted by: mb911 Jul 11 2017, 02:55 PM

If I were to do a group buy on both options it would make the most sense. The type 4 is an interesting thing as I don't have a type 4 to try it on and don't have laser cuts or drawings for the type 4 flanges so as far as what people may or may not want sound wise may not be an option because again I am only able to make 1 internal design.

Posted by: BillC Jul 11 2017, 04:11 PM

Well, if you do decide to do a T4 design, especially one that will fit a 1.7, I would definitely be interested.

If I were closer, I'd bring my car over for you to use as a guinea pig.

Posted by: maf914 Jul 11 2017, 05:13 PM

I would be interested in the muffler with inlets for a 73-74 2.0L T4. Good luck with this project.

Posted by: Dave_Darling Jul 11 2017, 05:48 PM

Remember that there are three different Type VI/914 exhaust flange patterns, and they all wind up at different heights/widths relative to the chassis of the car!!

Here is a diagram of the widths and such, courtesy of Jeff Bowlsby:


And, of course, the 75-76 version has a single pipe in each exchanger instead of the dual pipes.

Make sure you clearly note what version of the exhaust the muffler is compatible with. And if you can make versions that are compatible with each, that would be amazing... (And more expensive, sad to say.)

--DD

Posted by: mb911 Jul 11 2017, 07:54 PM

I think they will be too expensive for type 4 customer's.. I think even in a group buy i could see it at 700 to make money sense. With the -6 or 911 I can probably do it for less on a group buy .. Retail will be 800 plus though.

Posted by: Krieger Jul 11 2017, 09:16 PM

What do you think the weight would be compared to stock? And the reaching question, do you have any idea where the sound would be for us track guys with db requirements? With a stock muffler I have had no issues at Laguna Seca. I can't remember if it's 90 or 92 decibels.

Posted by: Justinp71 Jul 11 2017, 10:57 PM

Interesting... How do you think they'd compare to the original M&K dual in/single out?

They will be higher flowing, correct? Sound similar?

Posted by: gulf908 Jul 12 2017, 01:35 AM

Ben

still interested in a 2 in 1 out for my standard motor May '70 914-6
I would like to have the original Leistritz 901 sound as much as possible
let me know pls

TIA
Dennis

Posted by: mb911 Jul 12 2017, 10:18 AM

No not at all like an m&k they will sound similar to stock .. The goal is to produce something similar to stock in both sound and flow.

Posted by: mb911 Jul 12 2017, 10:19 AM

Should be just as loud as stock.

Posted by: bretth Jul 12 2017, 11:06 AM

Is it accurate that the early 911 and 914-6 mufflers have the same dimensions except for the bend in the tailpipe?

Brett

Posted by: mb911 Jul 12 2017, 11:07 AM

Yes.

Posted by: mb911 Jul 14 2017, 08:54 AM

Small update between the huge flodding amd lose of power for days around here.

Posted by: mb911 Jul 14 2017, 10:32 AM

Small update between the huge flodding amd lose of power for days around here.

Posted by: mb911 Jul 21 2017, 07:11 PM

Final prototype.. Ready for initial try.

Posted by: Steve Jul 21 2017, 08:09 PM

Have you figured out a group buy yet?

Posted by: rktmn247 Jul 21 2017, 08:18 PM

Looks nice. How much does it weigh? Would like to hear it with your headers.

Posted by: mb911 Jul 21 2017, 08:18 PM

Not yet but I will definitely do one to launch it.. Probably limit to the same amount of heat exchangers I sold and trying to make it work for everyone. I need to also get a realistic timeline for laser cutting so the group buy doesn't go for months on end.. I will send this muffler out for testing and then start the group buy..

Posted by: mb911 Jul 21 2017, 08:24 PM

I will have to weigh it when i get back. Up north right now fishing.

Posted by: mb911 Jul 25 2017, 11:12 AM

Ok so shipped today for the 1st test.. In the box with packaging material came in at shipped weight of 25lbs.. But for comparison the m&k sport muffler in a similar but smaller box and a smaller muffler all together ship weight is about 20lbs. I would put packaging at 3-4 lbs so gives you an idea. Once testing is completed I will start a group buy and with a real timeline delivered ..

Posted by: mb911 Jul 27 2017, 04:47 PM

Muffler currently being tested.. And possible going to a member here next for a track day but once that is confirmed and all of the fittment is done then start selling group buy priced.

Posted by: mb911 Jul 30 2017, 06:48 PM

Muffler is on the way to Gary as of right now he intends to use it this weekend to get feedback etc on the track.. The other test went well sounds just a touch louder then stock, no drone, just a touch to long sp hit a few little brackets on the 911 it was fit on. So far looking good.

Posted by: mb911 Aug 5 2017, 06:17 AM

So testing is going well and we new we needed to change tail pipe locations so that was just a confirmation.. Sound levels are hitting targets and the good news if someone wants it louder the old factory mods to a sport muffler work the same on this muffler..here is the feedback as quoted

"
Ok Ben, Just got home from muffler install. First impressions:

The fit finish quality is great.

As I am sure you know the tail pipe does not match up to the stock outlet location. Height wise and angle, it appears fine, but exits considerable more outboard from stock. It seems to me that the muffler body will have to be shorter or the tail pipe bend radius will have to be very tight.

I know you were trying to match the stock sound level. In my un-instrumented opinion, you pretty much did that. I can detect no significant difference in sound level or sound quality from stock. I suppose this will appeal to many, but for me, I want something more sporty when shelling out the bucks for an "aftermarket" muffler. Sorry, but if I wanted stock sound why wouldn't I just buy a stock muff?

Weighs in at 18 pounds even. The stock Liefrentz (sp?) comes in at 21.5.

No discernible difference in seat of the pants dyno readings.

So looks like I am all set for the track day on Saturday. Plan is to run it up the flag pole and see who salutes. Wish it had a little snarl to announce it's arrival. Keep in touch. "

Posted by: mepstein Aug 5 2017, 07:20 AM

I think for everyone who wants some snarl to the muffler there will be 10 who want stock quiet so they don't piss off the neighbors or drive the wife out of the passenger seat.

Posted by: mb911 Aug 5 2017, 07:47 AM

I would agree and the best part is the muffler is able to be modded to taste.

Posted by: Cairo94507 Aug 5 2017, 09:49 AM

Glad this project is progressing nicely. I have to admit I would like a bit more "snarl" than stock, but not much. But for me, the deciding fact will be this SS muffler will mate perfectly to Ben's large tube SS heat exchangers, since those are definitely going on my car. I want it all to match nicely.

Posted by: mb911 Aug 5 2017, 10:07 AM

I guess ultimately that is the mission is to produce packages.