openecu.org

Do the load values displayed in EcuEdit which are less than 1.00 indicate that we are in vacuum and the ones above 1.00 mean we're in boost? Better yet, Can someone provide me with the formula for calculating load? Thanks, JC

The load does not directly translate to boost. It is grams per cycle per cylinder I believe, though it is different depending on the ECU.

There are some other threads on this if you look around, but it basically is your total mass air flow (g/s) divided by rpm, and multiplied by another constant.

I agree with you technically speaking but I did some research on this and found that on my car the load and boost/MAP/MRP relationship is actually quite linear with a the vacuum/boost point being roughly a load of 1.6.

Well it might be close, but as the engine volumetric efficiency changes, so does the relation. It might be 1.6 at 4500rpm but 1.5 at 6000rpm and 1.2 at 7500rpm as the cams run out. You could data log to try to find out better, but it will vary a lot on different engines, different exhausts, turbos, etc.

I'd stick to doing all your math in absolute pressure and mass air flow. The ecu does.

Also, load is dealing with mass so it is not confused by temperature. 15psi at 50*F is quite a bit more mass than 15psi at 100*F. I think this is important because this is going to change significantly on a given car whereas VE changes will be small unless you swap hardware.

I agree on the temperature issue. But, for what I am looking at this for. it won't be an issue if I am few psi off. Thanks fellas.