Does anyone know how much 5zigen n1 cat back muffler will gain for my g20t please tell me

to be honest...
IMHO the gain will not be significant...
get the extractors with it then it's a different story

I didn't know 5zigen made catback exhaust for p11's. Correct me if I'm wrong. Catback exhaust will get you about 5hp.

yes 5zigen n1 catback had application for p11

Originally posted by 304border
yes 5zigen n1 catback had application for p11

Why don't you go with GReddy. Don't 5zigen exhaust have a rice burning sound?

i thought Apex-i made the N1.

5Zigen is most famous for the fireball, (like mine)