of what value is Gms/sec. I assume it is air flow calc based upon RPM MAP CID?

How does it know the CID if it uses it? Is it accurate?

What to use it for?

 

The gms/sec airfow calculation uses the engine displacement, VE, air density and RPM. It is fairly accurate and used for closed loop items and the IAT/CTS blend. Any table that uses gms/sec as a column or row label is from this value.

RBob.

 

Ron,

Really helps when adjusting Prop Gain tables. Makes a big difference in idle and steady throttle stability

 

I've noticed my Wideband O2 readings down low (less than 100 g/sec) have about 1.0 unit AFR difference while higher the AFR's are tight 14.5-15.1. Are my PRP values too loose in the lower g/sec areas? I'm not sure which table to adjust to get the AFR's tighter around 14.7 when I'm easy on the throttle

 

I would say my readings are similar.

I think there are a couple explanations. maybe the one of knowledge can confirm or deny.

1. lack of CFM flow through the intake tract. maybe the wetting of manifold is uneven with a 5% open TPS. Add to it a larger intake tract vs stock.
2. with a decent cam maybe some reversion and the exhaust is diluting the mix?
3. I run asynch at idle < 3 mph and maybe the fueling is affected in asynch.

 

I run sync all the time with O/L idle kicking in at 7 MPH. Also, Open loop decel helped my off throttle behavior. I using a 50mm bored intake setup, so I think it's getting enough air...
Maybe that might be part of my problem... the air comes in so fast and so much that any small changes in TPS have a proportionally larger effect on AFR when compared to stock.?

 

I misspoke. I too run synch <3 mph OL idle. but regardless I think larger than stock injectors at low msec DC make it diff to get a clean A/F. add to that lack of venturi speed with a larger TBI all adds to it. just like the large carbs we used to run on mod sleds make for a crap idle but fueled up on top nicely.