SR20VE conversion w/ EFR7670 low dyno numbers - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Kingtal0n · 08-23-2018, 10:25 AM

Another example from other thread

Pretty easy to see torque scale with boost. Just focus on torque because that is cylinder fill, which can only be 100% max. The engine clearly makes a max VE approaching 5500rpm where boost stops rising, max VE = max cylinder fill. Cylinder fill likely stays up after 7k because amazing VE head, but the turbo runs out of flow rate so the air loses density and power levels off. At that point is when we start to consider power and max flow rate and all of that because its the turbo's job to provide the dense air at high flow rates, and if can't keep up with the engines ability to flow then the only thing you can do is install larger turbo if you wanted more power. But max torque isn't going to get better with larger turbos or more head flow than this because adiabatic efficiency of compressors is pretty much standard as long as you are within the specific range the turbo prefers, and head flow rate isn't going to increase cylinder fill beyond 100%.

08-23-2018, 10:25 AM	#11
Kingtal0n Post Whore! Join Date: Jul 2005 Location: South Florida Age: 41 Posts: 4,829 Trader Rating: (17) Feedback Score: 17 reviews	Another example from other thread Pretty easy to see torque scale with boost. Just focus on torque because that is cylinder fill, which can only be 100% max. The engine clearly makes a max VE approaching 5500rpm where boost stops rising, max VE = max cylinder fill. Cylinder fill likely stays up after 7k because amazing VE head, but the turbo runs out of flow rate so the air loses density and power levels off. At that point is when we start to consider power and max flow rate and all of that because its the turbo's job to provide the dense air at high flow rates, and if can't keep up with the engines ability to flow then the only thing you can do is install larger turbo if you wanted more power. But max torque isn't going to get better with larger turbos or more head flow than this because adiabatic efficiency of compressors is pretty much standard as long as you are within the specific range the turbo prefers, and head flow rate isn't going to increase cylinder fill beyond 100%.