Pipe Engineering

[baz-r]

if you make 4-2-1 headers dont join un ballanced pairs thats the rule so 1+4 and 2+3 join first.
other wise the cyl the gets the exhaust stroke first creates high pressure wave in the exhaust that its joined to for the cyl that gets exhaust stroke next and as a 4pot will always have a fireing order where 1+2 and 3+4 next to each other in the firing order

the gap is 180deg bigger with a 1+4,2+3 split and power ballance is corrected