Airflow units in TP
Thread Starter
Supreme Member
Joined: Jan 2003
Posts: 4,624
Likes: 309
Airflow units in TP
Question... there are three tables in TP having to do with response to the O2 sensor which are based on airflow. The airflow seems to go from 0 to 64, but I can't find what units it's in.
Addresses are...
0x4CF Loop Closed Param, NOT Idling Prop Step Size Gain Multiplier .vs. Air Flow
0x4BD Loop Closed Param, SLOW o2 INT Delay Time .vs. Air Flow
0x4C6 Loop Closed Param, SLOW o2 Lag Filtering Coefficient .vs. Air Flow
When I open the detailed description and look at the units, it just says "airflow".
The only place where airflow units are actually stated is in the Inv MAT table where it says gm/sec. But that one goes from 0 to 256.
Addresses are...
0x4CF Loop Closed Param, NOT Idling Prop Step Size Gain Multiplier .vs. Air Flow
0x4BD Loop Closed Param, SLOW o2 INT Delay Time .vs. Air Flow
0x4C6 Loop Closed Param, SLOW o2 Lag Filtering Coefficient .vs. Air Flow
When I open the detailed description and look at the units, it just says "airflow".
The only place where airflow units are actually stated is in the Inv MAT table where it says gm/sec. But that one goes from 0 to 256.
Joined: Sep 2003
Posts: 25,895
Likes: 429
From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: Airflow units in TP
For some reason i thought they were gm/sec as well and only goes up to 64, not sure why but my guess was at lower air flows the o2 sensor reading mattered more as exhaust gas mass and volume is less, so more susceptible to idle and low throttle overlap events? Maybe emissions related tuning
Thread Starter
Supreme Member
Joined: Jan 2003
Posts: 4,624
Likes: 309
Re: Airflow units in TP
64 g/sec and an average air density of about 1 kg/cm^3 density at sea level, translates to only ~133 CFM if I'm doing the math correctly.
On a 350 (assuming say 50% VE for part throttle operation), that translates to ~2600 rpm, again if I'm doing the math correctly.
As you assume less %VE, the rpm will go up for the same 133 CFM, but that only means that these O2 tables are really only addressing lower and lower throttle openings as you get higher in RPM?
On a 350 (assuming say 50% VE for part throttle operation), that translates to ~2600 rpm, again if I'm doing the math correctly.
As you assume less %VE, the rpm will go up for the same 133 CFM, but that only means that these O2 tables are really only addressing lower and lower throttle openings as you get higher in RPM?
Senior Member
Joined: Jun 2010
Posts: 580
Likes: 32
From: Montgomery, AL
Car: 84 El Camino
Engine: 360 TPI
Transmission: 700R4
Axle/Gears: 3.42 + Truetrac, Moser 28 Spline
Re: Airflow units in TP
Question... there are three tables in TP having to do with response to the O2 sensor which are based on airflow. The airflow seems to go from 0 to 64, but I can't find what units it's in.
Addresses are...
0x4CF Loop Closed Param, NOT Idling Prop Step Size Gain Multiplier .vs. Air Flow
0x4BD Loop Closed Param, SLOW o2 INT Delay Time .vs. Air Flow
0x4C6 Loop Closed Param, SLOW o2 Lag Filtering Coefficient .vs. Air Flow
When I open the detailed description and look at the units, it just says "airflow".
The only place where airflow units are actually stated is in the Inv MAT table where it says gm/sec. But that one goes from 0 to 256.
Addresses are...
0x4CF Loop Closed Param, NOT Idling Prop Step Size Gain Multiplier .vs. Air Flow
0x4BD Loop Closed Param, SLOW o2 INT Delay Time .vs. Air Flow
0x4C6 Loop Closed Param, SLOW o2 Lag Filtering Coefficient .vs. Air Flow
When I open the detailed description and look at the units, it just says "airflow".
The only place where airflow units are actually stated is in the Inv MAT table where it says gm/sec. But that one goes from 0 to 256.
Also believe what RBob said regarding airflow and OL.
HTH, Elky
Thread
Thread Starter
Forum
Replies
Last Post