Hi,
Given a compression ratio of 9.3:1.
If we cannot increase the air flow (restrictive intercooler), but have a very strong turbo.
If the temperature is constant at 18°C.
If knocking is known to appear at 14:1.(arbitrary value, may be much more)
If the engine runs e85, mostly.
Is it better to increase the capacity of the engine or to sleeve it, reducing the -forged- pistons size?
Effects on torque?
I wonder because in my opinion, in this precise context, a smaller cylinder could make up for the restricted air flow, thus increasing the power output by improving the compression ratio. But too low and you loose too much torque/capacity and the big turbo becomes useless (oversized).
So, for example, going from 4.0tfsi to a 3.8 or 3.9 (yes, on a rs6).
What is your opinion?
Sent from my ALE-L21 using Tapatalk
Given a compression ratio of 9.3:1.
If we cannot increase the air flow (restrictive intercooler), but have a very strong turbo.
If the temperature is constant at 18°C.
If knocking is known to appear at 14:1.(arbitrary value, may be much more)
If the engine runs e85, mostly.
Is it better to increase the capacity of the engine or to sleeve it, reducing the -forged- pistons size?
Effects on torque?
I wonder because in my opinion, in this precise context, a smaller cylinder could make up for the restricted air flow, thus increasing the power output by improving the compression ratio. But too low and you loose too much torque/capacity and the big turbo becomes useless (oversized).
So, for example, going from 4.0tfsi to a 3.8 or 3.9 (yes, on a rs6).
What is your opinion?
Sent from my ALE-L21 using Tapatalk
