Throttle body set screw

[99STEPSIDE]

How do you determine what the proper setting is for the idle speed set screw? I've installed a new BBK throttle body, performed a RAFIG and AUTOVE, but it would seem everything is hinged on the throttle plate being set at proper opening prior to all this. Is there a correct method to determine where the screw should be set? Trying to get my ducks in a row, any help appreciated. Thanks.

[SSpdDmon]

You log IAC steps. When the car is up to temp, they should be ~70 steps.

[99STEPSIDE]

Thanks for the reply. If I have a cable driven TB, do I need to crack the plate any for bypass air?

[99STEPSIDE]

I think I found the answer in this post

http://forum.efilive.com/showthread.php?t=4219&highlight=log+iac+steps.

[redhardsupra]

did you change the effective area scalar?

[99STEPSIDE]

No, I hadn't changed the value. Thank you for bringing it to my attention. According to what I've found on the forum to determine the effective area scalar-

Area = pi * R ^2

R=1/2D, pi= 3.1416

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

For 80 mm A = 3.1416* (1/2 * 80 ) ^2 = 5026.56 sq mm

Units for B4349 are %/sq mm

100%/5026.55 sq mm= .0199 %/sq mm for the 80 mm TB

This value should be entered into B4349 (ETC Throttle Area Conversion)

Does this look right?

[redhardsupra]

yup. or you could use this spreadsheet: http://www.marcintology.com/tuning/TBresizing.xls

[99STEPSIDE]

Thanks again for your input. That's a great spreadsheet. After I've changed the value I need to rerun RAFIG and AutoVE, Correct?