Using "boosted" VE numbers for compressor maps.

[Matthew]

I was working on graphing some points on a compressor map for a friends soon to be turbo b18b, when i showed someone else my work, and they said i made a mistake. I had been using the rough number of 90% for the VE, which he agreed would be right if the engine was still sucking air in, but since air is being forced in, the VE number should be well over 100%.Does that make sense?Also, would that mean that a car you planned on running 1 .bar with, would have a 200% VE? So, does this also mean that the VE is depeandent on how many psi you are running?Thanks to anyone who clear my confusion up!

[S14Zilvia]

That doesn't sound right, I don't think it is... I thought it was NA numbers.

I'm sure wd or one of the other turbo gurus would know. I'll try to find the answer as well.

[C-Kwik]

A turbo will make VE over 100%. But most calculations for turbos use the NA VE figures as it almost directly correlates to how much airflow there will be when boosting. And a car running 1 bar could theoretically, hit 200%VE, but...since an NA motor will typically get less than 100% VE, then the actual overall VE will be less than 200%. Say a NA motor that hits 90% VE will see about 180% under 1 bar of boost. There are other factors, but this is kind of an all else equal answer to keep it simple.