Full Race Turbo Kit FN2z4

[mastuning]

Greeting everyone,

i did a quick couple of searching and could not come up with anything, i was in the process of tuning a very nice Type R that (left Hand)

ID1000cc
Hondata 4bar map sensor
Full Race turbo kit with BW turbo (great spooling)

after ironing out the tune in Speed Density for the fueling (those ID's are huge) only seeing around 6.8PW at 5500rpm 5.2 PSI

car ending up making 265whp with boost dropping to 4 psi


my question is how restrictive the stock exhaust, by how the boost drop i can tell its bottle necking.

what gains should be expected if we get this exhaust upgraded to something like 3inch?



Thanks