Did a 6466 1.0ar 4 inch downpipe and straight pipe.
It went faster at roll racing on the same boost as 6266.
200m roll racing with start 50km roll on.
26psi 6266 108mph
26psi 6466 114mph
Changes were turbo, downpipe from 3inch to 4 inch and diff gears from 3.08 to 4.1
Did around 20 runs.
Started on 20psi 9.5 degrees
ended at 26psi 10.5 degrees
wgdc on 6266 26psi 3 inch dump pipe 14psi wastegate 70%
wgdc 6466 25% 4 inch dump pipe 17psi wastegate 25%
No issues running plenty of back to back runs.
It sounds like absolute rubbish off boost but gets cracking once its on a bit of boost.
Heres about 10 runs on video.
Races agsinst 1108hp (Australian hp)2jz supra, supercharged ZL1, r33 skyline, Turbo Ls