Paul, Throttle body scaler.

[jfpilla]

As a result of trying to tune airflow I'm pretty certain the Effective Area table does not apply to the electronic throttle body.
There is a table called "Electronic Throttle Area Scaler", or the like, that seems to be what is needed.
Joe

[GMPX]

Not a table, but a single value {B4349}.

Cheers,
Ross

[jfpilla]

Not a table, but a single value {B4349}.

Cheers,
Ross

Ross,
Thanks.
Joe

[jfpilla]

Ross,
Is it valid to determine a factor by using the % difference between a 78mm and 90mm? .8667. Should it be used to multiply or divide .0254?
Thanks
Joe

[jfpilla]

Not a table, but a single value {B4349}.

Cheers,
Ross

Is it available yet? I can't find it.

[bink]

Joe,
V7.3
Engine Cal-> Idle ->General Parameters -> B4349 ETC Throttle Area Conversion - This calibration limits the desired idle effective area.

It works with my ETC (2001). Maybe you are too far out of range?? Have you checked the idle pids - Long term and short term idle trims??

joel

[bink]

Ross,
Is it valid to determine a factor by using the % difference between a 78mm and 90mm? .8667. Should it be used to multiply or divide .0254?
Thanks
Joe

I believe the 78 and 90 are diameters. Area of a circle:

Area = pi * R ^2

R=1/2D, pi= 3.1416

A= 3.1416 * (1/2D) ^2

For 78 mm A = 3.1416* (1/2 * 78 ) ^2 = 4778.38 mm2 = 47.78 cm2

90 mm A= 3.1416* (1/2 * 90) ^2 = 6361.74 mm2 = 63.61 cm2

63.61 cm2 ( 90 mm) / 47.78 cm2 ( 78mm) = 133.13 % increase in surface area.

Hope this helps some.

cheers,
joel

[jfpilla]

Joe,
V7.3
Engine Cal-> Idle ->General Parameters -> B4349 ETC Throttle Area Conversion - This calibration limits the desired idle effective area.

It's not there.

It works with my ETC (2001). Maybe you are too far out of range?? Have you checked the idle pids - Long term and short term idle trims??

What works? Eff. Area?

joel

[jfpilla]

Ross,
Is it valid to determine a factor by using the % difference between a 78mm and 90mm? .8667. Should it be used to multiply or divide .0254?
Thanks
Joe

I believe the 78 and 90 are diameters. Area of a circle:

Area = pi * R ^2

R=1/2D, pi= 3.1416

A= 3.1416 * (1/2D) ^2

For 78 mm A = 3.1416* (1/2 * 78 ) ^2 = 4778.38 mm2 = 47.78 cm2

90 mm A= 3.1416* (1/2 * 90) ^2 = 6361.74 mm2 = 63.61 cm2

63.61 cm2 ( 90 mm) / 47.78 cm2 ( 78mm) = 133.13 % increase in surface area.

Hope this helps some.

cheers,
joel

Thanks, Joel. Big help. Joe +33.13% ?

[bink]

Ross,
Is it valid to determine a factor by using the % difference between a 78mm and 90mm? .8667. Should it be used to multiply or divide .0254?
Thanks
Joe

I believe the 78 and 90 are diameters. Area of a circle:

Area = pi * R ^2

R=1/2D, pi= 3.1416

A= 3.1416 * (1/2D) ^2

For 78 mm A = 3.1416* (1/2 * 78 ) ^2 = 4778.38 mm2 = 47.78 cm2

90 mm A= 3.1416* (1/2 * 90) ^2 = 6361.74 mm2 = 63.61 cm2

63.61 cm2 ( 90 mm) / 47.78 cm2 ( 78mm) = 133.13 % increase in surface area.

Hope this helps some.

cheers,
joel

Thanks, Joel. Big help. Joe +33.13% ?

Joe - I copied the Max Desired Idle Area {B4350} description, above :oops: .
The correct B4349 description is -> "Used to convert a desired throttle area from square millimeters to ETC motor position".



Your 90 mmTB is 33% larger than a 78mm. I'm not sure if you shouldn't increase the B4950 above 84 - since your engine is 364 ci it should require more air at idle (~10.5%). If the Eff. Area Table doesn't work it would make sense it may be out of range . Your 84 mm2 / 174 step may not be enough. (moved 7 places/cells to right- IAC eff area?) :?