Ever wonder what denting headers for clearance actually costs you in performance?

[Ddaddy]

Denting a tube does not change its cross-section area. A circle bent into an oval has the same area, just in a different shape. Exhaust flow and resistance are determined by the cross section area of the conduit, not shape. The metal around the circumference of the shape would need to be folded and constricted in order to reduce the circumference and thereby change cross-sectional area.

Unless the metal is so extremely deformed as to reduce cross-section, dents won’t impact performance.

 

[famous bob]

BULLSHIT!!!...a restriction is a restriction no matter how big or small,must be nice you take a set of $900.00 TTI's and smash the **** out of them:violent1::violent1: as far as having to dent headers to get them to fit..not if you buy the right ones..i was happy to see the the *** monkeys blow the doors off of their shitbox charger with the dart

Not me , head *** monkey was an ***! Was scared of big h.p. too !

 

[mopowers]

Denting a tube does not change its cross-section area. A circle bent into an oval has the same area, just in a different shape.

Are you sure about that?

 

[diymirage]

Summit Racing SUM-640310 Summit Racing® Oval Exhaust Tubing | Summit Racing

 

[dart_68]

Denting a tube does not change its cross-section area. A circle bent into an oval has the same area, just in a different shape. Exhaust flow and resistance are determined by the cross section area of the conduit, not shape. The metal around the circumference of the shape would need to be folded and constricted in order to reduce the circumference and thereby change cross-sectional area.

Unless the metal is so extremely deformed as to reduce cross-section, dents won’t impact performance.

The cross sectional area total may not change but the shape of the tube can have a big affect on the ability for smooth flow. There should be virtually no affect in flow in a straight section but as soon as you add bends the shape of the tube can have a big impact if the shape changes at the bend.

 

[rklein383]

Unless the moron’s in the video are doctoring the numbers, I would think real world data would trump opinions.

 

[Phreakish]

Denting a tube does not change its cross-section area. A circle bent into an oval has the same area, just in a different shape.

Not entirely true. Think of it this way, a square with sides 3" long will have an area of 9 sqin and a perimeter of 12". Take that 12", and make a rectangle now that's 4"x2" and you get an area of 8 sqin. A circle with an area of 9 sqin will have a diameter of 3.38" and a perimeter (circumference) of 10.63"- conversely a circle with the same 12" circumference as the 3" square will have an area of 11.5 sqin.

But obviously the cross sectional area isn't the end-all be-all for header performance.

 

[rklein383]

I guess my thought is at what point is the cross sectional area of the header tube less than the cross sectional area of the exhaust valve opening area. Then does the header tube become the limiting factor?