Volumetric Efficiency

[NT TURBO]

Does anybody understand volumetric efficiency? I am trying to set up an OBDII link and one of the parameters is the VE, I understand there is a formula to calculate it but it would vary a lot depending on boost and revs. So when are the measurements taken to calculate volumetric efficiency? At idle,at cruise, on boost? has anyone already done this for a stock FG turbo?

Cheers, Mick.

["Captain Retard"]

I think VE is taken at peak torque.

It may be a bit harder working out VE with a boosted engine.

If you can find out the VE for a NA engine and then multiply that depending on PSI at peak torque.

Example :NA has 95%VE , air pressure is 15psi.

Turbo making 8psi at peak torque so 8 divided by 15=0.5333x100=53.33%

Add the 53.33%+95%=148.33% VE.

I'm not sure this is accurate though as you may have to take in other considerations like air temp and density etc.

I'm sure someone's done this before so just keep googling.

If you can't find a ford turbo6 then try and find a similar package with a VE you can use.

That's about all I've got.

I only ever used VE to calculate carb sizing on NA engines.

And even then I found it to be a bit unreliable as there's so many variables.

Sorry couldn't be more help!

[ratter]

^{some cars use a volumetric efficiency table (VE) for tuning, the falcon does not}

[Mr_4.0]

The old e series ecu's use a VE table.

[bjc]

Is this for the Torque app so it can determine power output at set rpm's?

I just use 85% for our engines but can't remember the last time I used the app to read power!

[NT TURBO]

Thanks for the replies, I have just been playing with a cheap OBDII reader and the DashCommand software and was trying to get it as accurate as possible.