Jeep 4.0 in 69 Barracuda
So not to get too geeky here, but the Surface Area of a 2.5 inch exhaust system is 4.9 inches. The Surface Area of a single 1.75 inch exhaust system is 2.4 inches. So a Siamese dual 1.75 inch system would be just a hair off of what a single 2.5 inch exhaust system at 4.8 inches. The presentation of of a Siamese system would absolutely killer, and the main benefit would probably be clearance.
Sorry,but that is inaccurate,allow me to to explain.First up,You are confusing surface
area w/ CROSS-SECTIONAL area,which is the dimension you stated.Secondly,the
inside dimensions are the ones you need to calculate for,which is approx. 1/8"less
for 90% of std. bendable exh. tubing and available in up to at least 12'sticks.
2.5"/ 1.75"x(2) / 1.125"x(6)
area) 4.43"sq./ 4.148"sq./ 4.71"sq.
circum.) 7.47" / 10.2" / 18.85"
surf.area/ 89.64"sq./ 122.4"sq./ 226.2"sq.
lin.ft.
It should be obvious the frictional area goes up w/multiple piping,even when the
cross-sectional area is the same,which I illustrated w/the 6 -1 1/8" pipe numbers.
This doesn't take into account frictional factors based on boundary layer shear &
tumble,which will remain constant on the surface regardless of pipe dia.This effect
will "shrink"the usable area of the pipe by approx. the same dimension,obviously
having a much more detrimental impact on smaller pipes than larger ones,which
have the mass fluid flow moving more freely in the center.
If ground clearance is an issue,you mite investigate Burns oval tubing as a much
better compromise,not cheap tho'.I like the center exh. exit concept,and you can
dual tip or Y-split two pipes out back if you use a single but like the "dual look".
Going to be a tite bit of work w/ the spare well there w/o it hanging low.Good luck
w/ the new place & let us know where you're at with this,I'm sure you know about
the factory offered pieces for that eng.,incl. a ported head etc., and FI means no
carb. air filter and the flexibility of something like pictured above, so hood issue
isn't as bad as it could be, Have fun!!!:coffee2:
