a call to inline 5 gurus everywhere........

[alan pritchard]

been rereading four stroke tuning by a. graham bell.  And more specifically
the area on exhaust design.  its all good going until it mentions headers, 4
cylinder, 6 cylinder, 8cylinder....... 4-2-1, 6-2-1etc.... and i know the
optimum design for the i5 is 5-3-1 (i think....)   but how does this work in
reality??? the book mentions on 4 cylinders, that cylinders that fire 180
degrees apart should pair up, and on v8's that cylinders that fire 270 + 450
degrees ( i think.... again....) pair up, so what do you do on a 5???? where
the cylinders fire every 144 degrees (i think lots) and if you pair headers
up you get one          spare..... my current manifold is the 5-2-1 variety
and it doesnt look right anyhow......
anyway, im contemplating making, or having made, a tubular manifold and
downpipe assembly and i really need some guidance, has any one got a custom
one made??? what does it look like, and is there any "magic" dimensions to
it or can it be made from good rule of thumb from a book like this. i know
the N/A quattro (or should that be Quattro) manifold and downpipe is 5-3-1
but i want to have a go, or at least do the math for this.

thanx!!!

alan whos spent too long in work welding up shiny things to go under his
bonnet....