Muffler suggestions

[branham76]

I want to keep the original headers for now (money wise) and just get the best exhaust i can find

[bpilati]

With my carb setup, I decided to use a 2 1/4" dia. custom-made Borla system. The 2 1/2" dia. muffler is identical in size to the 2 1/4". It fits well. You can see a few photos in the Members Gallery under Fixitman. A $100.00 for a muffler and tailpipe that will last over 10-15 years is a terrific deal. You just need to have the tailpipe welded on or one end flared.

If you are interested in a full S.S. system, I can put you in touch with MSA's supplier to have the pipes bent.

Fixitman

If you would like a quieter exhaust system, you could even add a Borla resonator.

I'm going to for 2-1/4" too, I hear it's gives you better mid-range power. 2-1/2" is good for racing and lots of high revs. That's what I hear.

[bpilati]

Custom order from Fujitsubo Japan. There's 3 of us on here with the same exhaust, but we all run different headers.

For now I'm staying with the original manifold, which actually has been given a pretty good rating for a casted exhaust manifold.

[LeonV]

I'm going to for 2-1/4" too, I hear it's gives you better mid-range power. 2-1/2" is good for racing and lots of high revs. That's what I hear.

Nope, not true. IF the 2.25" is limiting you, the 2.5" will be better in ALL aspects. If the 2.25" is not limiting you, and it probably wouldn't on a stock-ish L24, then a 2.5" will not hurt nor help. It'll just take away some ground clearance.

[ksbeta]

Custom order from Fujitsubo Japan. There's 3 of us on here with the same exhaust, but we all run different headers.

I'd be very interested to hear what this sounds like.

I've never been able to determine what header/exhaust/muffler combination is on my '70, but I love the sound:

[bpilati]

Nope, not true. IF the 2.25" is limiting you, the 2.5" will be better in ALL aspects. If the 2.25" is not limiting you, and it probably wouldn't on a stock-ish L24, then a 2.5" will not hurt nor help. It'll just take away some ground clearance.

It's the old back pressure argument. The engineer in me says the less restriction the better. More mass flow, less friction losses from turbulence is better. But some says you need back pressure; these discussions go back decades.

[LeonV]

It's the old back pressure argument. The engineer in me says the less restriction the better. More mass flow, less friction losses from turbulence is better. But some says you need back pressure; these discussions go back decades.

This has been discussed countless times. Those that wish to perpetuate the myth are ignorant of the facts. Discussions about the Earth being flat went on for quite a while, doesn't mean they were anywhere close to being right.

Hopefully, this thread can properly inform the "you-need-backpressure" crowd.

[sparegolfer]

What about 2 inch exhaust all the way back?

[LeonV]

What about 2 inch exhaust all the way back?

Too restrictive for best performance. However, if you don't care, then go for it.

My stock-cammed L24 has dual 2" pipes.

[bpilati]

This has been discussed countless times. Those that wish to perpetuate the myth are ignorant of the facts. Discussions about the Earth being flat went on for quite a while, doesn't mean they were anywhere close to being right.

Hopefully, this thread can properly inform the "you-need-backpressure" crowd.

Thanks Leon, good stuff. When we were designing systems for fluid flow in college, no one ever suggested we increase friction or reduce flow rate to improve efficiency. That's why I've always been baffled by the talk of backpressure.

[LeonV]

When we were designing systems for fluid flow in college, no one ever suggested we increase friction or reduce flow rate to improve efficiency.

Precisely!

[Captain Obvious]

You don't want back pressure. You want momentum.

Problem is that sometimes an increase in momentum is accompanied by an increase in back pressure.

I'm no expert in the field, but my theory is that since an increase in momentum is often accompanied by an increase in back pressure, people started thinking that back pressure was the desired effect, and it's not. It's the unwanted, but often necessary, side effect.