daidilus

i have a OBD1 converted 1998 auto that i turned into a manual LSvtec. i have a stock B18b1 bottom end with a B16a head and GSR cams, with B16 transaxle...I am getting a full JDM ITR intake manifold. i have a BBk 70mm TB laying around...should i use that throttle body? I have a SRI, 4-2-1 header and full BBP exhaust. It also has a chipped ECU p30 map with no knock and a 1834 fuel multiplier. I made the map with chrome. Everyone I know says i should use the BBK but i am not sure. Next week I ill be putting p30 pistons in it....

Schister66

If the engine is going to flow enough air to justify the upgrade, then yes. The problem with larger throttle bodies and intake manifolds is that when run a larger, less restrictive intake that flows more air, you inherently decrease the speed of the airflow provided the engine's intake needs remained constant (Bernoulli's Principle). Since airspeed and torque/response are related, you may lose some low end torque and response...and potentially gain in the top end.

This whole airspeed vs air volume issue is why GSRs have the goofy butterfly valves in the intake manifolds, or why my STi has TGV valves (essentially the same thing as the GSRs but electronically controlled rather than pneumatically)

Short Answer: Go for it, but you'll probably lose a little low end response as a result. Read above for explanation

10psiLsEf2

itr manifold and itr throttle will do you just right.