How calculate the area of the throttel body?

[The Swede]

Hi!

How do i calculate the correct area of the throttel body?

Should the TB area be the same as the area of the intake runners area together?

The setup is a SII with sheetmetal intake and Champion heads, will a 105mm. TB be enough?

 

[Jerryl]

I am no expert, but remember that the intake valves open in sequential order and “technically” a small TB "should be enough". This IS the complexity of the reciprocating multi cylinder four stroke engine. You get some ramming effect of the intake chanrge, boost, plenum size, exhaust variables, can timing, distribution, "Intake charge stop and go" effect, etc. It is a VERY complex model

Area = (3.14 x Dia x Dia) / 4
(Dia X Dia = Dia Squared)