Hey guys

Im just running a few numbers on some compressor maps and using the following figures:

Volumetric efficiency 0.92

BSFC 0.55

Pressure loss across system: 2 psi

Manifold Temperature: 130 deg farenheit

(Im calculating it all at 7200 rpms where I have my ignition cut).

These are just the generic numbers off the Garrett website for a 2 liter turbo. Now thinking about it - the Evo engine is pretty efficient so maybe I should pump up my VE a bit?

Do people here use different values than above when looking at compressor maps?

Thanks

 

Typical numbers for peak Volumetric Efficiency (VE) range in the 95%-99% for modern 4-valve heads, to 88% - 95% for 2-valve designs. If you have a torque curve for your engine, you can use this to estimate VE at various engine speeds. On a well-tuned engine, the VE will peak at the torque peak, and this number can be used to scale the VE at other engine speeds.

More info can be found here: http://www.xtremeboost.com/tb101_comp.html

 

Brilliant thanks for that.