Exhaust - 4 into 1

Planning to build a 4 into 1 exhaust system. What will be the correct inlet diameter of the silencer?

I have one megaphone silencer with 51mm inlet, and maybe this is big enough... ?

Br
Rune

 

I have a 93 VFR750F with one can. Inlet size is 76mm. 51mm may be a bit small.

Larry

 

Thanks for info. Maby someone have the pipe dimensions of an type "old kerker system"?

 

One more thing, is it the same 4-2-1 headers/manifold used on 1986/1987 and 1988/1989 ?

 

The slip on on my bike is around two inches or 50mm.

Roger