Help me build a new exhaust system :)

[2ManyZs]

Whatever you do don't buy those glasspacks some people are so hip to sell you. They are junk, and they end up being a straight pipe when the fiberglass packing burns out. Go with a "turbo-type" muffler for the best flow and sound. It's hard to say what is good since music to one mans ear is sometimes noise to another.

You could try the Supertrapp muffler. It has plates you take off or add on to "tune" the muffler to the sound level you want. They aren't much more expensive than the better turbo mufflers on the market and they give you the benefit of being adjustable.

The main thing about the header debate is this. If you really want one, don't skimp, buy the absolute best there is(normally the most expensive)and you shouldn't have as many problems. Some headers I have seen had such sloppy welding around the flanges they had 1/4 of the opening full of slag. Get done grinding them out and flat again and you've ground thru the weld and gone into the pipe. Break out the mig and re-weld it and start all over again. I have had fairly good luck with the MSA header as long as you file the flanges around the port to make sure it is flat.

Will you miss it if you don't have a header? Probably not. A friend of mine had a 73 with a stock manifold with MSA's 2 1/2 inch exhaust and it sounded just as good as any car with a header and the same exhaust.

[kmack]

So I should try and cram a "turbo-type" muffler in the tunnel along w/ the trans. and drive shaft? That sounds a little crowded. My "original" exhaust had a "glasspack" type installed there, that's the only reason I mentioned it. I know the pre-muffler is supposed to quite the resonating, but are you saying I should do w/o it? I hate to be picky here on this, but I'm getting close to to needing this.

[Mike]

Installing a good, well designed, and well built header will always increase horsepower. Why else would anyone want to install a header? What's the point?

If you look at the design of a header, you will see each pipe from the head down to the single pipe are the same length. If you were to take all the pipes off the engine and lay them next to each other (assuming that you could bend them so they lay straight), they will be identical in length.

The stock header is not designed this way. The exhaust enters a shared chamber and is then blown into a hole at the end where it's supposed to find the low pressure point... and eventually escape.

A header is designed to allow the exhaust gasses to smoothly exit the chamber and also provide the least resistence possible. By increasing the diameter of the pipe, the 'balance' of each cylinder, and the more efficient muffler... we are allowed to do this. The engine can 'breathe' easier.

Now, I don't know the reason why all of the header pipes are the same length. It allows all of the exhaust to exit at the same rate of speed and pressure, but, beyond that... I don't know. Anyone else want to chime in here? There are a lot of pro's out there that I KNOW have more information than I.

[Mike]

On a practical note....

I noticed a DRAMATIC increase in my engine after I installed the 6-to-1 header and 2.5" exhaust. I can't tell you if it was the header or the exhaust, but, I was very happy.

Acceleration was smoother and my engine just seemed to 'feel' better to me.

Someone once asked me, "Boy Mike, that doesn't sound like you have a L6 anymore..."

It was awesome. Makes me want to finish my project and get her on the road again.

[Marty Rogan]

Kmack,

The turbo muffler goes at the tail end of the car. Skip the resonator in the middle, you don't really need it. I was very picky about how the sound was. I didn't want the car to be loud. The shop convinced my to go without the resonator and even offfered to add one in if I didn't like the sound. It you go with a good quality, thick gauge 2 1/4" system, it will lessen the boominess you get witha 2 1/2" piped system.

With this setup, the car is nice and quiete, but has a nice growl when you tromp the gas.

Marty

[Si|v3r72]

SO how do you connect the 2 1/4" pipe to the manifold? Modify the "Y" connector? Will the 2-1 5/8" outlet openings in the manifold cause a restriction?

[Marty Rogan]

The muffler shop sort of cut the Y pipe in half, creating a larger opening and them bent and welded the 2 1/4 pipe to fit. A good muffler shop will figure it out.

As far as the flow goes, I have heard that the 240 monifold actually does flow pretty well. the larger pipes will help it breath easier/

[BILL COFFEY]

if you want a great sound for a stock system try using an austin healey 3000 muffler. it has two ins and two outs and will fit under the z perfect. if you have any questions let me know. the midas shop on federal highway in ft. lauderdale installed mine. good luck