It's not the fastest thing off the line, but that could be due to my disgustingly overported 65 eurokit. It gets into the powerband at around 38mph and at about 40, it starts to backfire and I haven't gone too much faster due to my bike cutting out because of a bad electrical system. Sorry.
I'll tell you how fast it goes once I get a CDI set-up or fix my electrical system. I'm sure with good electronics and no juvenile horrible port work, this pipe would have pretty good low and midrange and insane top end just like those Simoninis on Puch set-ups. It really kicks in once that powerband hits.
No pictures, but it's a Motomatic special. I wouldn't try to chop and bolt a factory one up. It'll just look silly.