What you said is right. But according to
Welcome to TurboByGarrett.com , the horsepower output of the engine does not increase according to the displacement. As in this formula:
Wa= HP* A/F *BCFC/60
Where:
· Wa = Airflowactual (lb/min)
· HP = Horsepower Target (flywheel)
· A/F= Air/Fuel Ratio
· BCFC/60= Brake Specific Fuel Consumption ( ) ÷ 60 (to convert from hours to minutes)
As you car see here, airflow target when searching for the suitable compressor doesn't take into account the effects of displacement. Since that is the case, how can HP increase when engine displacement increase?
In the same website, there is also this formula:
MAPreq=[Wa*R*(460+Tm)]/[Ve*N/2*Vd]
Where:
· MAPreq = Manifold Absolute Pressure (psia) required to meet the horsepower target
· Wa = Airflowactual(lb/min)
· R = Gas Constant = 639.6
· Tm = Intake Manifold Temperature (degrees F)
· VE = Volumetric Efficiency
· N = Engine speed (RPM)
· Vd = engine displacement (Cubic Inches, convert from liters to CI by multiplying by 61.02, ex. 2.0 liters * 61.02 = 122 CI)
In this formula, you can clearly see that Manifold Absolute Pressure is inversely proportional to the engine displacement. So, in this case, if you set the twin GTSS turbos to produce 1 bar boost in the 2.6 litre engine, when you use the turbos with the 4.5 litre engine, it will not hold 1 bar boost.
Is this true? What are the effects on the horsepower output on the engine? (Assume that turbine restriction doesn't exist)