This might help a few aspiring header builders. Use it to design your collector jigs.



If anybody has a better host let me know.

These are based around the Burns Stainless 15 degree mild or stainless 16 gauge bend.

 

measuring that precisely at those places is rather difficult.

add an angle in there and itll be a lot more helpful...

-derek

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dfoxengr &raquo;</TD></TR><TR><TD CLASS="quote">measuring that precisely at those places is rather difficult.

add an angle in there and itll be a lot more helpful...

-derek</TD></TR></TABLE>

I thought the same thing, but after looking at it for a while its easy to understand and figure out where to cut.

The only thing I can see that would make it easier is if you had this measurement.



http://img351.imageshack.us/my...j.jpg

Only because measuring a straight line on round pipe is not the easiest thing.

Either way thank you.

 

I'm not gonna do it all for you.

Gotta start somewhere, so here's a starting point to go from.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by k24em2 &raquo;</TD></TR><TR><TD CLASS="quote">I'm not gonna do it all for you.

Gotta start somewhere, so here's a starting point to go from.</TD></TR></TABLE>

I'm not complaining at all , I said thanks .

I already figured it out by the way.

 

Keep in mind you can move where you cut the bend to change the size of the outlet.

 

yes thank you very much

 

try this one. Its bigger and you can save picture as...

 

or do this

tangent of pipe angle / pipe radius = length of cut

its not perfect because to make the hole round you 'll need more material. but its a close estimate. Pi*D is the circumference. So you'd actually have to calculate the arc lenth of half of Pi*D for each side and then figure out exactly where you need to cut. cutting it perfectly in the middle just doesn't suffice.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ~RTErnie~ &raquo;</TD></TR><TR><TD CLASS="quote">or do this

tangent of pipe angle / pipe radius = length of cut

its not perfect because to make the hole round you 'll need more material. but its a close estimate. Pi*D is the circumference. So you'd actually have to calculate the arc lenth of half of Pi*D for each side and then figure out exactly where you need to cut. cutting it perfectly in the middle just doesn't suffice.</TD></TR></TABLE>

Are you sure you don't mean (tangent of pipe angle)*(pipe radius) = (length of cut) ?

 

Yea there is a little more math involved, but this was more as a starting point for people. Can't give away all the secrets at once.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by k24em2 &raquo;</TD></TR><TR><TD CLASS="quote">Yea there is a little more math involved, but this was more as a starting point for people. Can't give away all the secrets at once. </TD></TR></TABLE>

You better NOT.LOL

 

actually we were both wrong...

its radius of tube/tangent of angle = length of cut.

tan (angle)= opp/adjacent....so tangent of angle* length of cut= radius of tube....which is radius of tube/ tangent of angle= length of cut ....tada!

I'll sit down tomorrow and work up some math equations for people so they can get a perfect 2.5" outlet hole with those two pipe diameters. I luuuv math.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ~RTErnie~ &raquo;</TD></TR><TR><TD CLASS="quote">actually we were both wrong...

its radius of tube/tangent of angle = length of cut.

tan (angle)= opp/adjacent....so tangent of angle* length of cut= radius of tube....which is radius of tube/ tangent of angle= length of cut ....tada!

I'll sit down tomorrow and work up some math equations for people so they can get a perfect 2.5" outlet hole with those two pipe diameters. I luuuv math. </TD></TR></TABLE>

Way ahead of ya on that one. But i'm gonna give it all away. Its not really all that complicated if you sit down and think about it for a few min. Drawing a picture helps.

 

for a 1.75" runner with a 15 degree bend and a 2.5" outlet on the collector...

the length of the cut needs to be ~ 2.764" and the height is 1.07129 (note these two are perpendicular to each other.)

this is what they need to be in order to get a TRUE 2.5" outlet. You'd need to take it to an exhaust shop to round the pipe...but easily done.

all you need to know how to do is use sines, cosines, tangents, law of similar angles, radian-degree conversions, know about the correlation between arc length and radius of tube...and I think thats tit.

I think I will go through my work and simplify it into a small equation so that you can change variables(IE tube diameter, tube angle, collector oulet diameter) But its late and Im tired.

 

Excel that **** if you get really bored.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ~RTErnie~ &raquo;</TD></TR><TR><TD CLASS="quote">actually we were both wrong...

its radius of tube/tangent of angle = length of cut.

tan (angle)= opp/adjacent....so tangent of angle* length of cut= radius of tube....which is radius of tube/ tangent of angle= length of cut ....tada!

I'll sit down tomorrow and work up some math equations for people so they can get a perfect 2.5" outlet hole with those two pipe diameters. I luuuv math. </TD></TR></TABLE>

I wasn't sure what you were referring to with radius of tube and length of cut and where the angle was, all I noticed was the units didn't match up. But I follow the angle you're referring to now.

 

I will

 

It seems that imageshack is down. Odd. Oh well everyone thank Randy. Hah.