Trying to get a better powerband out of an old V1 pipe. These pipes rip through the low and mid range, but once you hit about 8500 rpms, it'll just scream at you in agony as you push it to 10k+ trying to over rev a few more mph out of it.
The stock header pipe is 20mm ID all the way from the last U bend, so I cut it back, welded a 30mm ID U bend in, then a 26mm header pipe, and finally, a 21mm ID converging pipe at the flange to match my polini.
And it's a side bleed. (No baffle, because it's being used on a track bike.)
Hopefully this broadens the powerband and doesn't ruin it.
Haven't tested it yet, due to southern California's infamous Santa Ana winds kicking gusts up to 50mph. There's garbage cans blowing down my street faster than my moped, so I'll have to wait a bit.