The $200 Porsche Exhaust

[bullethole]

I have a magnaflow 2 in 2 out like the original poster did (i spoke with Steve Weiner about this and took his recommendations (bought the parts from him, as he was so helpful and I wanted togive him the business). I've had no problems running at LRP in DE's with this setup

[jamesjedi]

Any chance of someone posting the pipe size/bends need to be purchased?

Also, are the flanges bought from any muffler supply?

[Jeff Higgins]

The Magnaflow #11385 that I used has 2.25" inlets and outlets. I used four 90 degree and two 45 degree pre-formed bends in 2.25" diameter. That's all the pipe I needed - the pre-formed bends have enough straight section on both sides of the bends that you won't need any straight pieces.

Make the flanges by laying out the two mounting holes and the exhaust pipe hole on a piece of flat stock. Drill the mounting holes up full size and the pipe hole to .250". Finish the pipe hole with a hole saw with a .250" pilot. One the holes are drilled, just cut out the flange on a bandsaw or something. Or you can just buy finished flanges from M&K. Or you can just cut them off an old crapped out muffler.

[JeremyD]

I too have a $200 exhaust - although mine is from the parts bin.









it's a 997 "center muffler" attached to B & B Headers. The spacing is pretty good for the application. - had my exhaust guy adapt.

[jamesjedi]

Great explanation. Thanks.

[lonewolf]

This is Great post Jeff. Cats out of the bag now.
The muffer makers( Some)will not like you but this is a very good and inexpensive setup and all the bends and pipe are available at any speedshop. Once you have one of these you'll probably never go back. cost is just too different.
Little story.
I like the twin pipe idea but $1000 for a muffler?
I made this same setup back in 97 when racing . My friend owned Mopac a speedshop up here so I was lucky I could take a bunch of mufflers home for fit and dyno and bring back what I didn't want to keep. Back then most of the 2in and outs were for the camaro or regals and they didn't have the size selection they have today.
I test fitted a borla which fit the best because it has narrow ends, then a magnaflow and a flowmaster amoung others.
Both the mag and borla are the typical stainless steel can with a perforated pipe going through it .some have round holes,some oval,some triangular holes in the perforated pipes and all have their reasons behind them.both packed with stainless steel strands. Supertaps use fiberglass packing and it burns up pretty easy.
The flowmaster is their own delta design chamber muffler but based on the same low, high decible priciples(sound waves) like the porsche bannana mufflers. The flowmaster design acts as a vacuum and helps suck the exhaust out of the engine and through the muffler where others force exhaust into and through the muffler. If you pick a muffler that is too small you will end up with a dark spot in the middle of it where the pipes cross.
The flowmaster has a distink sound which everyone recongnizes and was the heaviest but it did have the best performance. I wanted to use the borla because of the clean look but went for the flowmaster.Basically we found that the revs snapped quiker with the flowy.
When I showed up at the track with a flowmaster bolted to my Porsche man I heard about it from the purists., Mostly because of the sound,detroit iron muffler on my german machine etc.
Many racecars today use this two in two out style muffler now and most use flowmaster. I know a big buck team.650hp plus twin turbo cars and they use this setup with a flowmasterfor years now with no issues.
This system will cost you about 200.00 give or take. + you can get them anywhere
Magnaflow and flowmaster make a lot of different sizes of the two in two out style so it's easy to get the right fit.
I'll say in closing the twin pipe looks cool on the cars but it's pretty darn hard to beat the engines performance from the stock 2in1out banana muffler on our motors.
Of course you can't get a new banana muffler for 79.00
We just did a friends 911 using a polished magnaflow and all stainless tubing to match the SSIs.
Sounds and looks great.

[Arne2]

What about trying a Magnaflow 12266 Camaro muffler to build a 1 in / 2 out? I wonder how loud it would be?

[lonewolf]

I have used the one in one out magnaflow on a 3.0.
with the cat on it sounds fine .nice sound all the way.
without the cat it's more rumbbly and gets loud in the high rev range but it is still a nice strong sound and not raspy
buddy has 40000 miles on his and still sounds the same and the outside still looks good ,not all burned up .

[Arne2]

My only fear with the above Magnaflow would be loudness. Dual out can be loud. I ran a one in/two out Magnaflow on my 240Z. It was remarkably loud. However, it was also a VERY small muffler case (3.5x7 oval, 14" case). Perhaps the larger case above wouldn't be too bad.

I'd really like to go two out on my car, but most of the options appear to be either expensive, too loud or too much drone. Not many good choices.

[lonewolf]

If you do some reasearch you'll find magnaflow make a LOT of mufflers. At first I thought there was only a couple 2in 2out but found out they make about 20 of them.
the one you used on the Z is a small can so not much muffling ability.

One thing you must concider is inlet and outlet size and length because that effects performance.
It can get complicated if you don't know what your doing.

[Arne2]

Yeah, I know how that works. I figure a much larger Magnaflow should be quieter than the little bitty one I had on the Z.

But the reality is, I doubt I'll be able to experiment much on this. My wife is still rides me about the effort, fussing and expense of my learning curve on doing the roll-your-own exhaust on the Z. (I was trying to replicate a long unavailable period exhaust. Finally got there, but the path was rather long, and the cost was MUCH higher than I had estimated.) So I fear I'll need to stay with something off-the-shelf to keep peace here at home. But since most two-out systems have loudness/drone issues, I'll probably end up going with a "safe" choice like a one-in/one-out M&K or Dansk Sport.

[mppickett]

This particular muffler is very loud. The outlet that is on the same end as the inlet has absolutely no baffling, just an angled redirect fom the inlet. I ended up blocking off that outlet and using it as a 1 in, 1 out. It was reasonable in that configuration.

Originally Posted by Arne2

What about trying a Magnaflow 12266 Camaro muffler to build a 1 in / 2 out? I wonder how loud it would be?

[Arne2]

Thank you for that first hand info, Mike. I think that probably eliminates any thoughts of an affordable two-out that won't be too loud or drone.

But I could possibly still fab a single-out with a Magnaflow. I do like how those mufflers sound. Too bad this one (#14210) only comes in full polish, that makes it more expensive than it needs to be. Other than the price, it should make for a good option.

[jamesjedi]

JeremyD, that looks great.

What does it weigh when compared to a Magnaflow, or, what can you tell us about it?

I have often thought that the 964 C2 center muffler could be used as well.

[JeremyD]

It's not bad weight wise. I had a magnaflow on my old 3.4 carrera and it was loud - even my 10 year old son complained.

This is loud - but not as bad.

Here's the 3.4 with the magnaflow
3.4 carrera with B&B and magnaflow - YouTube

Here's the 3.6 with the 997 center exhaust
coming home - YouTube

[jamesjedi]

The "loud thing" and "resonance" gets very tiresome. But it does sound amazing!

It is good to find a balance. It sounds like this can be done with certain Magnaflow/Flowmax mufflers.

[Canuck_Targa]

I installed a similar DynoMax 17676 one in one out on my 84, and there is no resonance at any rpm. It has worked well, but I have heard that they eventually burn out, especially if used for racing. For under a hundred bucks I paid for it, I will just replace or try something different.
Here is a clip of the sound.

84 Porsche 911 Carrera Dynomax sound clip.WMV - YouTube

[ltusler]

Using the Magnaflow just watch out for the outlet ends, they need to be mounted, I had a dual in/out on my 996 and the vibration broke the end cap below the weld on one side. Also Dynomax makes a dual in/out with a X flow internal set up. I'm trying that next.
Dynomax Ultra Flo X-Pipe Mufflers - SummitRacing.com

[Jens]

[Jens]