2 1/4" True Duals
Likely better ways to spend money unless you can get it done cheap.
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A 2.75” (stock) single system is good for a 310hp engine with zero loss…
A 3” Single system is good for a 370hp engine with zero loss…
A 3.5” Single system is good for a 503hp engine with zero loss…
A 4” Single system is good for a 657hp engine with zero loss…
A 2.25” dual system is good for a 457hp engine with zero loss…
A 2.5” dual system is good for a 513hp engine with zero loss…
A 3” dual system is good for a 812hp engine with zero loss…
The Best V8 Stories One Small Block at Time
A 2.75” (stock) single system is good for a 310hp engine with zero loss…
A 3” Single system is good for a 370hp engine with zero loss…
A 3.5” Single system is good for a 503hp engine with zero loss…
A 4” Single system is good for a 657hp engine with zero loss…
A 2.25” dual system is good for a 457hp engine with zero loss…
A 2.5” dual system is good for a 513hp engine with zero loss…
A 3” dual system is good for a 812hp engine with zero loss…
A 2.75” (stock) single system is good for a 310hp engine with zero loss…
A 3” Single system is good for a 370hp engine with zero loss…
A 3.5” Single system is good for a 503hp engine with zero loss…
A 4” Single system is good for a 657hp engine with zero loss…
A 2.25” dual system is good for a 457hp engine with zero loss…
A 2.5” dual system is good for a 513hp engine with zero loss…
A 3” dual system is good for a 812hp engine with zero loss…
The underlying information is taken from a 2005 magazine article. The magazine article assumes, counterfactually, that there is a linear relationship between pipe sizes and volumetric flow gas flow based on relative cross sectional area. The actual relationship between pipe sizes is far more complicated and is usually calculated using complex engineering formulas. Those complex calculations however, can be reduced for estimating purposes to an exponential relationship.
In the attachment below I have substituted the actual exponential relationships and recalulated the relative horsepower levels assuming that the lowest horsepower shown in the magazine article (310 horsepower) is measured.
In most case the corrected data will not lead to a different conclusion regarding which exhaust systems are appropriate. There are however, a couple instances where the miscalulations in the magazine article suggest more horsepower from an exhaust configuration that actually has a lower flow capacity.
The underlying information is taken from a 2005 magazine article. The magazine article assumes, counterfactually, that there is a linear relationship between pipe sizes and volumetric flow gas flow based on relative cross sectional area. The actual relationship between pipe sizes is far more complicated and is usually calculated using complex engineering formulas. Those complex calculations however, can be reduced for estimating purposes to an exponential relationship.
In the attachment below I have substituted the actual exponential relationships and recalulated the relative horsepower levels assuming that the lowest horsepower shown in the magazine article (310 horsepower) is measured.
In most case the corrected data will not lead to a different conclusion regarding which exhaust systems are appropriate. There are however, a couple instances where the miscalulations in the magazine article suggest more horsepower from an exhaust configuration that actually has a lower flow capacity.
And I don't really care what that info from the stickies said, I had 2 1/4" with dual cutouts, with them closed I lost ET/MPH and gained with them open (they are less than a foot behind the collectors). Now that I have 3" I do not gain anything by opening them.
I say if it makes more power at all then go for it. I would rather have the comfort of knowing Im not leaving anything on the table with my exhaust.
just my 2 cents









