roll8221

Thinking about doing a new intake and throttle body on my b18c1 build. Is the extra airflow needed with a forced induction setup? Will it be decreasing the pressure due to the added flow? Will I see any increase in performance or a decrease?

OneBadTurboCRV

What power levels are we talking?

Yes you can go too big.
As long as the throttle body isn't a restriction (at least matches the Intercooler piping size) there isn't much of a need to go bigger on the average setup.
Decrease pressure? Please elaborate this mode of thinking...
Increase or Decrease power? Again, what is the setup you have and are thinking of going to?

This is WAY too vague of a thread.

wantboost

iTrader: (2)

Like he said, normally it just needs to match the intercooler piping size.

Above 500hp 2.5" piping becomes a restriction and you need at least a 75mm tb.

But your question is way too vague for a specific answer

We need your full setup, power goals, the purpose of the car, etc before we can even begin to give specifics

yungkhmer

Port match it to the intake mani.

Turbo-LS

iTrader: (4)

Charge pipe sizing has a lot to do with internal air speed its not as simple as 500 its a restriction. I believe 2.5" will support u to .39mach or about 750cfm before there is a problem.

wantboost

iTrader: (2)

This is very true, but I've seen numerous cases of high power cars going from 2.5 to 3" and making a lot more power before retuning.

roll8221

B18c1, T3/T4 Turbo, .50 A/R Compressor, .63A/R Turbine, 3" Inlet Diameter & 2" Outlet Diameter, currently a stock intake and throttle-body, definately less than 500 HP....Not sure what other info you might need. I was looking at the skunk 2 pro manifolds with one of thier alpha throttle bodies (70mm port matched to pro manifold), but wasnt sure if bigger was necessarily better such as the 70mm versus the 68mm. Not sure what the mode of thinking was, just wasnt sure if the increase in throttle body bore would effect performance in a positive or negative way. what it boils down to is what size throttle body would be appropriate for the setup, if a change from stock is needed, and would i see significant enough power gains to make the upgrade...

roll8221

-Hasport Mounts
-CP 81.5 Pistons
-Manley h-beam rods
-ACL bearings
-ARP main and head studs
-Supertech valves, springs, retainers, guides, seals
-Supertech block gaurd
-Clutchmasters 6 puck stage 4
-Aeromotive 340 fuel pump
-AEM fuel rail
-AEM fuel pressure regulator
-ID 725cc injectors
-OEM gaskets, oil pump, water pump
-hondata s300
-somewhere around 9.8:1 cr
-moroso 5.5quart pan
-Daily driver
-adding parts where i can
Hope this helps fill in any blanks...
all the help is appreciated...

roll8221

2.5 inch piping...