Exhaust bore question

[xoldog400]

Hi, i'm going to put a custom exhaust system on my 172, so my question is will a 55 mm bore be ok (the engine is stock) ?
55 mm is i think 2.125'' (scorpion systems are made like that for 172).

thanks!

 

[Fred@BTM]

bit small, you want power, you want 2.5inch (aka 63.5mm)