Rally 3 class

[OldF]

How much hp will you get with changing the restriction from 31 to 32 mm, and from 31 to 33 mm?

Increasing the diameter of a 30 mm restrictor by 1 mm increases the area by 6,6 % and assuming a constant air to fuel ratio the power would also increase by 6,6 %

31 mm -> 32 mm = (32 * 32) / (31 * 31) = 1,0656 => 6,56 %
31 mm -> 33 mm = (33 * 33) / (31 * 31) = 1,1332 => 13,3 %