I replaced the muffler on my Bursch exhaust with a Magnaflow and made before and after sound clips. I was hoping the swap would give me a more aggressive sound and better flow. It really didn't make a big difference in sound. If anything, the Magnaflow muffler might be a touch quieter. Guess I'm just used to the rumble of my Chevy v8's and was expecting too much. It does have a little deeper sound to it. It also has to flow much better because it is a straight through design. Sure was a pain to install because the case is a little bigger and it had to be just right to not hit or rub anything. I had to make a little dimple on the muffler in one spot to clear one of the exhaust hanger bolts up top.

My conclusion: It sounds fine, but it's not the grunt I was hoping for. If I would have known the outcome before doing the swap, there's no way I would of done all that cutting, fitting, and welding. Probably not worth the effort unless you're looking for a better flowing muffler or your current muffler is rusted out.

Here's the sound clips (might have to turn up your volume)....

Bursch Muffler... http://www.supload.com/Bursch-download-U1vpbM.html


Magnaflow Muffler (part# 11124)... http://www.supload.com/914-Magnaflow-download-XCQ1HM.html

Forgot to add this is on my stock 73 2.0 car.

Magnaflow definitely sounds better on my macbook tin speakers. I'll have to listen to it later in the office with 100 watts.

Second one is Throaty

Have you heard a Triad? I think you may like the sound.

http://www.youtube.com/watch?v=NBf1cpu2A2k

I looked into those because I do like the sound. It's more than I want to spend right now though. I'd have to get a new valance as well.

Dave (of Triad) actually offers 2 options if you want to keep your stock valance:

1. Go w/ his dual outlet exhaust but have the passenger-side pipe point down (if you search this board, you'll see photos), or

2. You can opt to have a single-outlet exhaust made, though Dave doesn't seem to favor the design. But it is an option.

For the money ($320 last I ordered), I think you get good value. Triad is one of my favorite exhausts for -4 cars. For -6 applications (I'm running one with my 3.2), I have a love/hate relationship w/ the thing - love the sound when I'm driving hard, hate the droning/resonance in the cabin when putzing about at lower rpm ranges (1500-3000, varying between different gears, with my setup). There's also conflicting opinions about the actual design in terms of affecting performance, but since I'm no exhaust expert, I'll leave it to anyone interested to research and draw their own conclusions.

Magnaflow def sounds better over my speakers. Quieter on the idle and low end, but more throat on the gas. If you had to replace it, I would call it a success.

Mike

You just had to get me researching the Triad more. Now I want one!!!

The Bursch was louder at idle. I have a Bursch exhaust that I might just tack a magnaflow on to. I like the fact that the rasp is gone. Ii would definitely be louder on a carb'd car (like mine!), but probably not be too loud.

I love the sound of the Triad. But it tends to wear on you when you're on the road for a while. If you want a louder (and lower) sound, the Triad is the way to go.

I have a bursch with a busted muffler, so this might be a good plan for me if I can't get the eurorace to work the way I want.

If you don't like the magnaflow, let's talk. I can send you the broken bursch in trade so you can try another muffler + cash for yours with the magnaflow.

Let me know.

Thanks for the offer, but I'm going to leave the exhaust on for now. Only way it's going to come off is if I buy a new bolt on exhaust.

If you're going to replace your muffler, might want to find one with closer dimensions to the bursch muffler. The Magnaflow is just a little fatter, which caused it to hit or rub on the stock heat shield. I ended up cutting the support brace that ran from the tailpipe to the driver exhaust flange. Welded it back on in a way that it pulled the muffler down a little so it cleared the heat shield. Also had to put a dent in the muffler to clear one of the exhaust hanger studs up top.

I also modified the tailpipe so it hugs the valance closer. Wasn't necessary, but I think it looks better. Also painted it with high temp grill paint and added a new crome tip for that extra bling.

I'll try to post a couple pics today.

So why would the muffler sound louder with a card'd engine? Is it the result of using a beefier cam which keeps the valves open a bit longer, resulting in more exhaust pressure? I can't think of any other reason the carbs would cause the engine exhaust to be louder...

Eric Read

Maybe more air and fuel has something to do with it?

Sounds nice. Just save your pennies and get the Triad when you are ready. I have never heard a 914 sound so nice as they do with a Triad on. Well, other than a twin plugged 914-6 that had a stockish 911 muffler on there. I think that twin plug just sounds hot.

My buddy has a 74 2.0l that sounds close to my 6 with both having Triad on there. His has the tip turned down on one side so he didn't have to do anything with the valance.

So you're telling me that an exact same engine, with no change of anything except the replacement of FI to carbs, will suddenly flow more air through the engine? The cam and the valves have nothing to do with the air flow through the engine?

Then why can I get better HP with my FI than with a carb, given I don't change the cam or the valve geometry?

Or are you saying the inefficiency of the carb setup provides for more air throughput at lower efficency levels?

Thanks!

Eric

I have noticed that when you switch from FI to carbs the noise isn't just the exhaust. It may sound like it but you are hearing a lot of noise from the carbs. Oh, and you should be able to tune the carbs to work with the flow of the exhaust to gain more HP. I heard that somewhere . FI needs a certain amount of back pressure but carbs need to flow. The wider exhausts allows air to be pulled through faster and carbs allow this to happen. This is just what I was taught. If it is poor teaching I wam willing to be taught correctly

You'll argue anything...

Some of the additional noise on a carb'd car is the carbs themselves. But all things being equal, a carb'd car's exhaust is slightly louder than a FI car. I don't know (or care) why that is, but it is what it is.

I just thought carbs were less restrictive as far as air flow into the engine. I'm not sure if it is actually true, which is why I ended my statement with a question mark.

I know 4 venturis on 2 Weber 40IDF carbs are larger than one 914 2.0 DJet throttle body. The logical conclusion is that they would flow more air (I would think anyway).

BTW - Sorry for the thread hijack!

Interesting topic here

I never considered the idea that the air flow is so restricted by the FI throttle body. My assumption has always been that the opening and closing of the valves, and the size of the valves are the main restiction point to air flow through the engine. Does the FI throttle so restrict the air flow to the intake valves that the engine is partially starved for air? If so, that would seem to me as a major design flaw...

I too have "heard" that an exhaust system is louder with carbs, but I have always believed that was because of the accompanying change in the cam and valves that allowed more air to flow.

So does anybody know the answers to this?

Eric

intake noise is "muffled" by stock type air cleaners. when converting to carbs not many people put a stock type air cleaner on.

a trick on the old 'merican iron to make them sound tougher was to flip the lid on the air cleaner soo that the lid had a gap 'bout 1-1/2 " and then you could really hear the secondaries howl!

fuel injection doesn't like "back pressure any more than carbs... fi doesn't like alot of over lap in cam timing that causes the "lumpy" idle.

next time a ricer goes by that has a "cold air intake "upgrade" most of the noise you hear is intake noise [the high velocity air moving past the intake valve]

that is if they don't have that big assed fart can on the tail pipe.

I like the sound of the 2nd recording. Real queston- is there any difference in the performance?
I think that the dual carbs definitely have more efficient air flow thru the motor and make more noise.