ETC Area Scalar

[MarkTucker]

Can someone check to make sure I am scaling the ETC Area Scalar correctly when changing throttle bodies?

LSJ Throttle Body= 67.4mm
LS4 Throttle Body= 75mm

Use (pi x rad. x rad.) - (dia. x shaft thickness) to find throttle body area. *rad.=throttle body radius & dia.=throttle body diameter*
67.4mm= (pi x 33.7 x 33.7) - (67.4 x 9.198813)= 2,947.8753607554 *shaft thickness found from ZZP site*
75mm= (pi x 37.5 x 37.5) - (75 x 9.7333333)= 3,687.8646691106 *shaft thickness found from ZZP site*

Use (75mm area / 67.4mm area) to find the ratio of the two areas.
(3,687.8646691106 / 2,947.8753607554)= 1.2510246255

Use (Stock Value x Ratio) to find ETC Area Scalar. *Stock Value= Stock ETC Area Scalar Value & Ratio= ratio of the two areas found in the step before*
(2,950 x 1.2510246255)= 3,690.522645225

Let me know what you think of this.

[KLUG'S SS]

You know I've actually got a chart deal I made up for throttle body scaling at one time, let me see if I can find it.

[MarkTucker]

You know I've actually got a chart deal I made up for throttle body scaling at one time, let me see if I can find it.

That would be awesome, thank you.

[laser_racer]

Your math looks good. I usually play with it to make sure timing doesn't get way out of wake at idle.

[MarkTucker]

Your math looks good. I usually play with it to make sure timing doesn't get way out of wake at idle.

Alright, thanks man

[ChrisA]

Since the P12 ETC parameters are non-existent in HPT, you can pretty much just throw in a number that works best for a given setup. My TVS with a 3.5" intake likes 5615. An M62 car I did with an Injen liked 3050. Other cars have been anywhere in the ~3200-4800 range. Your math is sound, but without the ability to change anything else it's not critical.