Exhaust Pipe Diameter 273

[MoparDart68]

Just wondering what size exhaust piping I should be running behind a stock 273 2bbl. Been wanting to do a dual exhaust system for a while from the manifolds back. Thoughts on H or X pipe? Is it even necessary with a stock motor like mine? Undecided on mufflers too, any suggestions would be appreciated. Thanks!

 

[Abodybomber]

2 1/4"- 2 1/2".,be good. Spend the extra money ,on over the axle tailpipes. Your ears,will thank you.

 

[/6 Matt]

If its stock I would say 2-1/4" dual and use the X-pipe. X-pipes always give gain. Are you running headers or manifolds?

 

[lou3500]

I have a 66 cuda with a 273 2 bbl motor [running a 4bbl intake] stock manifolds I have a true dual 2 1/4 system [no x or h pipe] 1 7/8 head pipes [to the bottom of firewall] stepped up to 2 1/4 stepped up to 2 1/2 at the mufflers and tips. I'm running Magna flow Magna packs [stainless straight thru] mufflers with stainless oval tips. Sounds awesome [quite loud] inside and out. My exhaust guy asked what I was wanting and I said I wanted to make small children cry when it was running he gave me what I wanted.

 

[TrailBeast]

Everything I have ever seen says the smaller the cubic inches, the more difference the X pipe makes.

 

[roccodart440]

Just wondering what size exhaust piping I should be running behind a stock 273 2bbl. Been wanting to do a dual exhaust system for a while from the manifolds back. Thoughts on H or X pipe? Is it even necessary with a stock motor like mine? Undecided on mufflers too, any suggestions would be appreciated. Thanks!

Whatever size your collectors are is ideal however that isn't always possible.

X pipe over H pipe but it isn't necessary but will yield you multiple gains over a straight dual system.

Mufflers...anything but flowmasters will be fine.

 

[340 8BBL]

if its bone stock,and you plan on keeping it stock or close to it,id run dual 2" front to back.an x or h pipe will smooth up/quiet the exhaust note some and possibly add a little low end over true duals.as for mufflers.....any decent performance muffler will do its more about the sound you want.

 

[1968FormulaS340]

Minimum I would put on any V8 is 2 1/4". This will be fine on a stock engine and give you wiggle room for adding more power later.

2 1/4" will support your average street machine, running 13s, all day long.

If your future plans include getting more serious, pushing into the low 12s, high 11s for example, don't buy twice, just get 2 1/2" now.

 

[MoparDart68]

Thanks for the input everyone! I'm running the stock manifolds btw. I got an estimate a while back: $650 [FM 40 series, without an X-Pipe (seemed a bit high)]. Thinking I might shop around a bit more...I know a lot of people are anti-flowmaster. I've always loved the sound, but not so sure it would sound right on a 4-Door.

Making small children cry?? That's a new one, lol.

 

[MoparDart68]

If your future plans include getting more serious, pushing into the low 12s, high 11s for example, don't buy twice, just get 2 1/2" now.

Never plan to go that far. When I eventually rebuild the 273, I might hop it up a bit to commando specs, but that's about it. I like the idea of having a smaller displacement and original block in the car. Would 2.5" be overkill for now on the stock motor?

 

[1968FormulaS340]

Never plan to go that far. When I eventually rebuild the 273, I might hop it up a bit to commando specs, but that's about it. I like the idea of having a smaller displacement and original block in the car. Would 2.5" be overkill for now on the stock motor?

If it were my car, given your performance goals, I would go with 2 1/4". I wouldn't even think about using 2 1/2".

I would also go with DynoMax Super turbos. I can't stand Flowmasters, but this is personal preference.

 

[340 8BBL]

well being a fabricator by trade,and having built multiple exhaust systems,id say 2.5 duals it a little overkill for a stock 273.considering the opening on the exhaust manifold is like 1 3/4"-1 7/8" it would be like hooking a fire hose to a residential hose bib.plus its heavier,harder to route,and more expensive.if you look at the commando 273 exhaust its a very well thought out system.the y pipe dumps into a single 2.5 mid pipe with a 2.25 tail pipe.the pics posted of the 2.25 system with magnapacs is also a good example of a well crafted system,but its the largest id go for what you are doing.jmo.

 

[lou3500]

Thanks 340 I went to an exhaust guy that I was referred to and he fabricated what you see for about 5 bills, it sounds awesome no rattles and everything is even [the guy is a perfectionist] he recommended no x or h pipe he bumped it to 2 1/2 for the muffs and tips for more sound, I am going to do some head work and port match everything when I rebuild the motor. I like loud my motto if you can't hear it, it ain't worth havin!!!

 

[MoparDart68]

Thanks for the pics, Lou. Nice setup you have there.

 

[rumblefish360]

Flow Masters just do not flow so well. That's why most are anti Flowmaster.

 

[RedFish]

With 40 series flow masters, don't plan on listening to the radio or anything other than exhaust drone. The single left to right strap under pre 68 fuel tank will likely be in the way. There are routes around it but I thought I should mention it just so you know what's in store.
A good bit of restriction exists in those stock manifolds so dual pipes wont have much effect on performance.

 

[MoparDart68]

I had the 40 series on my 318 Duster. Paired with headers, they were pretty loud at the tips. I decided to chop off the tail pipes (just behind the muffler outlet) one day to see what kind of racket I could make. Now, that was some serious noise right there, especially inside. They sounded great once you got on the throttle, but I couldn't hear my sound system anymore...Not really going for performance, just sound.

 

[roccodart440]

Flow Masters just do not flow so well. That's why most are anti Flowmaster.

With 40 series flow masters, don't plan on listening to the radio or anything other than exhaust drone. The single left to right strap under pre 68 fuel tank will likely be in the way. There are routes around it but I thought I should mention it just so you know what's in store.
A good bit of restriction exists in those stock manifolds so dual pipes wont have much effect on performance.

Those are my 2 issues with flowmaster. They don't "flow" and the interior resonance and or noise is too much. I've run glasspacks that were quieter inside the car.

 

[dynodonn]

Never plan to go that far. When I eventually rebuild the 273, I might hop it up a bit to commando specs, but that's about it. I like the idea of having a smaller displacement and original block in the car. Would 2.5" be overkill for now on the stock motor?

My 1965 Barracuda has the 235 HP Commando engine, and I'm running stock exhaust manifolds with 2-1/4" pipes, no "X" or "H" pipes, & Flowmaster SS mufflers. It sounds great.

 

[lou3500]

This was requested sound clip of my magna flow magna packs in my garage.

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