Avanti Noise!

[mfg]

Mufflers made for Studebaker Avantis and early Avanti ll's have a 2" inlet and a 13/4" outlet...(ID's).........True?

[r1lark]

Had a set of NOS Avanti mufflers (not the quiet ones!) that I sold a few years ago, but don't remember the inlet and outlet diameters. But I'm going to say true - 2" inlet and 1-3/4" outlet since this is also the diameters on other Studebaker V8 exhaust systems (except '55 tailpipes which were 2").

[regnalbob]

False. They are both 2 inch because the muffler has no specific inlet or outlet.

Edited October 25, 2015 by Regnalbob

[Gunslinger]

Agreed. The pipes were 2" all the way and the straight through glass packs were not directional. That must have saved time assembling and installing the exhaust system.

[r1lark]

Cool, learn something every day from this forum.

[mfg]

Answer.....FALSE!

[brad]

^{Oddly enough, the first Studebakers to utilize dual exhaust (55's) also used larger tail pipes of 2" instead of the later 1 3/4 " .}

[plwindish]

I'm curious as to the engineering idea of going with a 2" inlet and a 1 3/4" outlet on the mufflers. Be it ever so slight, but there's still a reduction of 1/4" of pipe diameter that's going to slow the flow down, or is this a "venturi" effect where the air and exhaust hitting a restriction actually speeds up passing through the restriction??

[Gunslinger]

I don't understand the science and technology behind exhaust flow...some of what I've always understood to be true have been disproven over time so I'll refrain of making a guess based on the science. I will say costs may have something to do with it. If the flow difference might be negligible between a 1 3/4" and 2" piping, then there's some cost savings in the smaller diameter pipe...less steel used in it, plus easier to install as it's less likely to rub against the frame somewhere.

There's also the ad value of saying you have bigger pipes all the way back. It depends on which is more important...the actual costs or value of the publicity.

In general though...follow the money.

[Avanti83]

I'm curious as to the engineering idea of going with a 2" inlet and a 1 3/4" outlet on the mufflers. Be it ever so slight, but there's still a reduction of 1/4" of pipe diameter that's going to slow the flow down, or is this a "venturi" effect where the air and exhaust hitting a restriction actually speeds up passing through the restriction??

Any time you reduce the cross section the flow must go up under standard conditions, what goes in must come out.

Remember that the muffler is probably a cooling area also so it's probably close to a wash.

Edited October 26, 2015 by Avanti83

[BRitz]

http://www.exhaustvideos.com/faq/how-to-calculate-muffler-size-pipe-diameter/

Some interesting info can be found at the link above. It's all about flow, backpressure, & resonance.

[plwindish]

Thanks, that was a good educational article on intake and exhaust piping needs.

[BRitz]

Thanks, that was a good educational article on intake and exhaust piping needs.

Welcome. Next time you go to the monthly meeting at Mr. Beef bring along a copy of this http://sem-proceedings.com/27i/sem.org-IMAC-XXVII-Conf-s33p005-Optimization-Dynamic-Response-Complete-Exhaust-System.pdf if anyone dares to question your knowledge of exhaust systems! LOL.

Everything boils down to "simple" math.

[plwindish]

Wow, that has got to be the definitive source for all exhaust knowledge! I think my engineer daughter is going to have to help me travel through the technical geek speak to fully understand it! Thanks, I'm sure that will more than quench anyone's "exhausting" thirst.

[Gunslinger]

That's definitely interesting stuff. I just wonder how much of this knowledge was known when Studebaker was building cars and how much of it was actually utilized if it was known.

[GlennW]

Though Studebaker engineering was often on par with it's competitors, I'd guess in this case it had more to do with cost, convenience, etc. than anything else. As mentioned, by the time the exhaust exits the mufflers it has cooled and reduced in volume compared to when it first left the headers, so the slightly reduced final pipe diameter probably has no measurable affect at stock HP levels.