i've got an '88 TII, 2.5" TID, 2.5" Turbo Back*RP Downpipe & Midpipe (using a 2.5" resonator in place of stock cat, but will eventually put a high flow cat) flowing through a 2.5" GReddy Power Extreme (Single)

before, i had a test pipe in and it was really loud but i'd smack about 12psi or so, but lately after installing the resonator it's staying around 10.2psi or so (im guessing from the resonator? impeading some flow so the boost tapers off compared to the test pipe?)

my question is, im going to be looking for about 12psi daily...how much should i port the wastegate? i read somewhere here that the stock WG is pretty small..but for my goal would i need to add the washer to the WG flapper? i wouldn't think so...

also, what fuel upgrades should i look into to keep up with 12psi?

'88 TII
Custom 2.5" TID w/ Bomz metal mesh filter
GReddy Type-S (Black) BOV
GReddy BOV I/C Pipe
Rotary Performance 2.5" Downpipe
Rotary Performance 2.5" Connector Pipe
OBX-R 2.5" Resonator
Custom Mandrel 2.5" GReddy Power Extreme Cat-back
Lower Shores Manual Boost Controller
Defi Boost D-Gauge
Blitz Dual Turbo Timer DC2
HKS PFC F-Con
HKS Fuel Cut Defencer
Spec Stg 2 Clutch

 

i just ported mine and i went 1mm smaller than the stock flap- i used to overboost to 14psi all the time now i hold a steady 6-7- there is no need to add a washer

 

You probobally could have searched and found t least 3 threads with this information. From What I understand if you know how to port properly you can get away with porting to the stock flapper size. Some people have ported beyond that and made a new bigger flapper, but a lot of my friends only have theirs ported to the edge of the stock flapper and are fine.

 

if it's an s4 wastegate...go for the washer...if it's s5, I think you can get away with just porting as much as possible. Here's good writeup.

http://www.fc3spro.com/TECH/MODS/TURBO/wgp.htm