3" exhaust? 2.5" exhaust...??

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rumblefish360 said:
I don't find the statement to broad. I see it as accurate and very much so to a degree.
I guess this truth depends on the end users use of the car followed by the ears abilty to put up woth the noise. I don't consider his build particularly powerful. I'm sure he is making a bunch of it (HP & TQ) and it is a barrel of fun for sure. The engine masters exhaust tube video is an interesting one. it was a 15.7/13 TQ/HP gain on that engine. Of course, your results may vary.....
620hp/580 - TQ open header
614/569 HP/TQ - 3 inch exhaust
601/554 HP/TQ - 2-1/2 exchaust
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you're just arguing to argue.. evidenced by the fact that your first sentence ends with "to a degree" ----
"2.5 is more than enough. It is more than enough on a small block motor." That is paramount to saying: 3" is the only system you should ever use on a big block. Too broad, too blanket and just doesn't take into consideration so many variables.
You're money on with everything else, but to simply say one size fits all is blasphemy.
 
ScampMike said:
you're just arguing to argue.. evidenced by the fact that your first sentence ends with "to a degree" ----
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No, I'm not arguing just to do so.
ScampMike said:
"2.5 is more than enough. It is more than enough on a small block motor."
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I never said that but do tend to argree that it will work well for most engines.
ScampMike said:
That is paramount to saying: 3" is the only system you should ever use on a big block. Too broad, too blanket and just doesn't take into consideration so many variables.
You're money on with everything else, but to simply say one size fits all is blasphemy.
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I agree and never disagreed.

And like I said, it depends on the end users use of the car. Perhaps, just maybe, a quiter ride is what he wants in the long run for long hauls? Perhaps, he doesn't care and wants every last pony available? As posted, the video is an interesting video. Like I said, to a degree, I agree.
 
When I had the 340 in my street/strip Dart it had TTI headers and 2 1/2" exhaust with flowmaster 40's and turn downs at the rear axle there was a significant et drop by dropping the exhaust. I'm sure some of it was the weight but the exhaust wasn't that heavy.

When I built the 408 I went with Hedman's, 1 7/8" primaries and 3 1/2" collectors, 3" pipes and Pypes mufflers with turn downs at the rear end. The car would lose less than a tenth in the 1/8 with the exhaust, 6.57-60 with out to 6.66-68 with.

I have the same header/exhaust on the 434 and it's gone 6.44 @ 107.1 in street trim and made 543 hp on pump 93 on a chassis dyno. It's never been ran without the exhaust so I don't know what it'll do.
 
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Did you purchase those 1-7/8 with the idea of going to a stroker?

IF you had that engine in more of a everyday car to and from everything, which exhaust would yor ears like better?

543 HP, NICE!
 
rumblefish360 said:
Did you purchase those 1-7/8 with the idea of going to a stroker?

IF you had that engine in more of a everyday car to and from everything, which exhaust would yor ears like better?

543 HP, NICE!
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Yes, I bought the headers when I built the 408.

As far as the noise goes I can't tell my car is any louder inside than before, there is no drone or annoying reverb. It does get loud when I'm on it though and the 434 has a different sound than the 340 or the 408.
 
..I just watched the Magnaflow exhaust video and normally don't see much in the magazines beyond advertising.
I have no experience with hi output big blocks but wonder if tuning an engine that was running rich could pick up 10 hp?
..perhaps tweaking the carb and adding a degree or two timing?
 
I also see things like this; 2-1/2 for the street, 3 inch for the track, small block or big block, it doesn't really matter.
On the street, unless your a street racer, you'll still have great power and decent sound control with the 2-1/2.

When your at the track, sound control is best answered with 3 letters. FTW!
 
I see it like this. I race my street car at the track through the mufflers in DOT classes. IT's a pain to drop the exhaust. I had to buy an exhaust. Not a huge price difference. So I went 3".
 
My 416 stroker is in the 450-500 hp range. Havnt dyno it yet. My dougs headers have a 3" collector. So I thought I would try 3" x pipes with 3" mufflers that drop to 2 1/2" going out to the tailpipes and tips. So far its a great sound and nice tone and seems to breath real nice with the aluminum
 
3" pipe off the collectors to some electronic cutouts with 2.5" from there back works pretty well.
 
Come on guys a little reading comprehension please. The original poster asked "Has anyone done and comparison of a 3" vs 2.5" exhaust on a mild stock stroke small block?" He asked based on a "mild, stock stroke small block. I stand by what I said and I'll defend it to the death. (quote from John Wayne's son in a movie) Any guess's?

2.5" is more than enough, and the benefit of weight/space/price savings over a 3" in this particular case is the best choice based on the current provided information.
 
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