Another Exhaust question :P

[rommaster2]

Ok well i tried the search but it always just comes up with every single thread that might come "close" so sorry if this has been answered.

Basically i have a fairly stock six, and i am not planning on hopping it up very much. I don't plan on putting in an aftermarket cam, and i don't plan on doing a head job. Still though i want a dual exhaust, for sound, and looks.

My question then comes to this, since i don't want to hop it up much at all i was thinking of getting this done the easiest way using a stock exhaust manifold. What is the biggest pipe i could run with a stock manifold?

My plan is to use a Y pipe, and split it off into two pipes, then maybe an X pipe, followed by a split again, cherry bomb mufflers, and the pipes ending just out the back. Would this work? Would it even sound good?

 

[shmoozo]

Ok well i tried the search but it always just comes up with every single thread that might come "close" so sorry if this has been answered.

Basically i have a fairly stock six, and i am not planning on hopping it up very much. I don't plan on putting in an aftermarket cam, and i don't plan on doing a head job. Still though i want a dual exhaust, for sound, and looks.

My question then comes to this, since i don't want to hop it up much at all i was thinking of getting this done the easiest way using a stock exhaust manifold. What is the biggest pipe i could run with a stock manifold?

My plan is to use a Y pipe, and split it off into two pipes, then maybe an X pipe, followed by a split again, cherry bomb mufflers, and the pipes ending just out the back. Would this work? Would it even sound good?

Well, it would get the exhaust gases to the rear of the car safely enough, but it's needlessly complicated. It's not going to flow any better than a properly sized single exhaust and it's really not likely to sound any better, either.

If you are going to stick with the stock exhaust manifold then I would advise you to simply run one pipe to somewhere near the rear of the car, then split the exhaust off into two tips using a Y-pipe to give you that dual exhaust look.

You could either use a single Cherry Bomb muffler in the section before the Y-pipe, or you could use two of them after the Y-pipe so that you'd have one for each tip. I'd just use the one, myself. It would cost less and be easier to run, plus it would sound just about the same either way.

 

[69Falcon]

Ditto. Keep it simple; there's no need for an X-pipe since you're coming off the stock manifold, you'll only need a single Y-pipe to split it. The decision then is do you split it before or after the muffler(s)? My vote would be after; you could run a single muffler up under the body of the car, about even with the backseat, then split it and run pipes around either side of the gas tank.

 

[rommaster2]

wow, after reading your posts it sounds alot better, much simpler at least . I would love to get a header, but yeah since i'm not really upgrading much from stock i can't really justify buying a nice header, it doesnt sound that bad like it is now, just a bit quiet so i wouldnt be upset if it was just a little louder.

 

[CZLN6]

Howdy Ron and all:

The largest head pipe you can use with a '63 and later cast exhasut manifold is 2". Given your criteria, I'd use a 2" pipe to the muffler then spit for the dual look. A 2" system will give you a noticeable improvement over a stock system, both in sound, mileage and performance- mostly in look and sound.

Anything else will add more weight, and rust out faster due to condensation and not enough heat to properly clean and dry it out.

Enjoy!!!

Adios, David

 

[rommaster2]

Thanks for the size info too, 2 inches is exactly what i was hoping it would be. So much is getting done on the falcon right now that i'm definitely getting closer to doing the exhaust so this information has been very helpful

 

[61bluebird]

i have a 77 comet with a 250 ,i y piped it and ran the exhaust back to two 12 inch glasspacks sounds good not too loud

 

[TheDude]

You'll notice a big difference with a better header and a good exhaust system even without any other upgrades. I installed a header on my stock 200ci and could easily feel a difference with the header and upgraded exhaust.

 

[SteveS]

I've been reading the above with interest. My 82 has 1 and 7/8" exhaust now. I've been thinking that, in my case, going from the cat back with 2.5" and a free flowing muffler. I'd be only going up 5/8ths.

The real question is wouldn't a free flowing exhaust in any case lean out the engine? Or is this not an issue when increasing the flow and size when the change is modest vice aggressive.

 

[69Falcon]

Yes, it will most likely lean out the engine, so you'll need to adjust the carb.

 

[CZLN6]

Howdy All:

Here's a couple more FYIs on this issue.

The outlet in the stock OEM '63 and later exhaust manifold, where the head pipe fits into it, is 2". So going to a larger diameter exhaust system with a stock exhaust manifold would not gain much, if anything.

The area of a 1.75" OD pipe is 2.06".
The area of a 2.00" OD pipe is 2.74".
That equates to about a 25% increase in area. That's a nice increase.
(IF you do the math, know that the inner diameter is less than the OD.)

Going to a 2.25" increases the area to 3.55", but velocity and heat goes down. Velocity and heat are needed to combat condensation and corrosion. This is especially true when considering the stock exhaust manifold outlet of 2"".

Yes, going to a larger diameter, more efficient exhaust system will lean out the engine slightly. In all most all cases where an improved exhaust is added to a mostly stock engine, farther leaning of the carb is not necessary as most stock systems are rich to begin with.

Depending on how restricted the stock system was, you may find; that the engine runs cooler, gets better mileage, revs easier, and sounds better. Engine vacuum and/or idle speed may increase slightly.

Adios, David