SLS

Actually cutting pipe @ an angle does increase the ID of the pipe. Your looking @ it from the wrong aspect. How much the diameter is increased will depend on the degree the angle is cut @. So technically speaking a pie cut will flow more air due to its increased diameter. Wether or not it flows better is to be argued but it will definatly flow more. I could prove this by cutting a few pipes @ different angles and measuring the ID but i dont care enough to do so, if someone does go for it.

BoosTedZSix

i can see smaller angles making it flow more air but thats a whole lot of welding lol. It would be interesting though if you dynoe'd the current dp thats on the car and a mandrel bent dp.

hotrex

the mandrel bent piece will outflow a pie cut any day of the week.

even though it may be minutely larger in regars to inside diameter, the flow will be disrupted by the cuts, and the inside half of the tig welds, regardless if its backpurged or not. but they look cool

wannabe

Ok john, now you have my official permission to suck a fat ****! even if it doesnt flow better, the inside diameter is STILL bigger, whether you are smart enough to measure the right place or not... on a side note, hows megans crx coming?

hotrex

who cares if its bigger if it flows worse.

rollmodel

Here is a question about the pie cutting method.

If you cut a piece of straight tubing at whatever angle you choose (I assume the pie cutting method is 7-8 degrees). So on a 3in pipe the angle has increased the cross section of the cut and if you have any length to this pipe (assume that you need a small straight section to weld to, you are still back to 3in, am I wrong? You did not stretch the pipe. So, you can argue that this pie cut piece which has one cross section of 3.022 inches then necks down to 3 inch and then back again to 3.022 inch.

So, if you take this to the extreme and apply the 'pie cut theory', make a cut that is 20 degrees, or 40 degree angles, now you have increased the diameter to 3.19. If you market this, you have just increased the 3in pipe without the use of a mandrel bender.

Now, if you take and cut these pie cuts so there is no straight section, so there are hundreds of these, even thousands to make a bend (this is also known as integration in math class ) you have tried to make a 'mandrel' bend.

If you want to know more, check out turbulent flow or a properties of air flow (also treated as a fluid) dealing with the reynolds number.

They look cool, if you are looking for the welding look. (I personally give credit to the work required)
They may be more cost effective (compare electricity vs. purchasing a mandrel bent pipe)
They may fit in tighter places (assuming some company does not make the bend radius tight enough)

But to claim they flow better because you have 'increased' the pipe diameter.....

ososlohatch

hotrex is right for once... and so was jeff by having some fun ... whitey pie cuts are larger on the inside but dont flow more cfm than the same diameter mandrel bend ... there's a reason we dont have pie cuts intakes on all motor cars

rollmodel

oh and on topic.

Car looks good. good luck at the races with that thing

Darkelvis

Joel, seriously ---- you. I TEACH MATH!!! you measure diameter at a 90* angle perpendicular to the pipe, if you are measuring at any angle other than 90* it isn't the ------- diameter. Want another picture? Using the same theory that you are trying to say is true then you could measure a 3 inch U bend to be MUCH bigger than 3 inches. Just look at this picture, since I measured "diameter" where I would cut it at an angle does that mean that this pipe now has a 7" diameter instead of a 3". NO IT ------- DOESN'T.



And her car will be done for Perfect 10.

hotrex

---- yeah *****