To start at the beginning, it’s always the best place
The idea had grown from my first exhaust build, originally it had 2 outlets instead of 1 but cornering was horrific, so it was changed to 1, that’s the photo at the bottom of the Home Screen.
From there it grew over many hundreds of thousands of kilometres, to wanting it to be
#1- a 4 into 2 with 180 degree tuning,
#2 - a free flowing pipe
(what’s that I heard you ask) 🤷♂️🤷♂️
180 tuning is running 1 and 4 together into a collecter and 2 and 3 down the other side,
That’s the first part, the second part was instead of a standard H pipe I wanted to incorporate a X into the system
But not just any X, I wanted mine to have flowing corners for a more stream line air flow.
This is where exhaust theories can get mixed up, the way I read it,😏at idle the gases from the left side pipes cross into the Rhs outlets and vise-versa, at full noise however the pressure combined gases at the junction sends the gases from left out the left and right with right, so my thinking why not make the X curved👍,
The next problem, which was actually the very first question, is what dictates the length of the header pipe, is it asthetics ( because a collecter in front of the motor would look out of place, or is it a numbers thing,🤔 it turns out mathematically ( on the headers I used) that 2 and 3 are exactly double the area of my bore. 295 cc + a bit for compression chamber, let’s call it 300 cc
The pipes are 600 mm by volume of water, 1 and 4 were 50 ml shorter.
I wanted 4 exact same length pipes, I failed miserably at that within 1 hour of the build, I wasn’t able to get to the oil filter🤦♂️ So I made 1 and 4 even shorter 😳
Here you can see the X in the system taking shape too, the other advantage as it turned out by cutting the outside pipes was I could change the entry angle into the collecter which was in unexpected huge bonus, cutting the pipes shorter also allowed me to tuck the outside pipes under 2 and 3 giving more room in the centre and more room on the outside to cater for the RH cross member mount
After the X the next decision was long or short primaries, I went with long, and I wanted to use the old Transac mufflers ( just because), initially they were going to be cut in half to finish under the rear foot peg, bloody glad I didn’t because they would be way to loud for me,
So the end result is in the first post, exceptionally happy with how they turned out, now to get them built properly and 180 tuned, 👍
