Volumetric Efficiency

[XTurboSpYderX]

I searched, and read through all 23 threads that contain the words Volumetric Efficiency (this took QUITE AWHILE). This question has been asked at least twice (that I have found), but never awnsered (again, that I found)... does anyone know the stock VE for our cars? OR, does anyone know the VE for THEIR car with their modifications?

 

[ericm555]

I took the HP and size of a 1G NT motor and calculated a VE of 84%. It seems kind of low for an engine with the port size it does. It may work better under boost though. This is the turbo calculator screen with the info I have.

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[XTurboSpYderX]

That is the same calculator I am using... I am trying to plot several points across several different compressor maps... for my own personal edification mostly... but I need at least a quasi-accurate VE across the RPM band to more accurately plot said points.

just a thought... wouldn't VE for a turbocharged engine almost always be over %100, for purposes of calculation anyway? i.e. if you were running 1 bar of boost you would double the N/A VE for the car as you are putting twice as much "ambient pressure" air into the cylinder?

 

[ericm555]

This calculator asks for a NA VE. The turbocharged VE would be around 137% on the stock motor.

 

[2-0turbo]

Originally posted by ericm555
This calculator asks for a NA VE. The turbocharged VE would be around 137% on the stock motor.

No it won't. Making the assumption that turbocharged VE is over 100% is not the correct approach. You need to take the turbo out of the equation when figuring VE. I'll explain later at home tonight.

 

[XTurboSpYderX]

Originally posted by 2-0turbo


No it won't. Making the assumption that turbocharged VE is over 100% is not the correct approach. You need to take the turbo out of the equation when figuring VE. I'll explain later at home tonight.

that would be greatly appreciated...


at one point I thought I had it... but now I am totally confused again... in some calculations it takes about %122-%130 for the stock numbers to come out right... but in others it takes about %85-%93...

 

[ericm555]

The peak VE is 84% at 6000rpm and it will be lower than that at any other RPM. Here is an example of a T4 map at 22psi.

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[pimpngear]

I am trying not to get off subject, but i did a few searches, and I can't find this calculator anywere....can XTurboSpYderX or ericm555 throw me a link? Thanks.

 

[WhatsADSM]

http://www.turbofast.com.au/tfcalc.html

 

[pimpngear]

kick a$$..this site has all sorts of goodies. Thanks WhatsADSM.