Set Effective Area For 90MM TB first or just do RAFIG without it?

[efizjb]

I've done a lot of post searching here and at LS1tech, it appears the jury is still out on whether you need to adjust the effective area for a 90MM TB.

I see a lot that says it helped, and other say it doesn't matter just do the RAFIG leaving the effective area alone and it won't matter. I'm guessing it would make sense to adjust the effective area setting and then do RAFIG. Upon searching it appears the # to set it at is .0320

It also appears most of the talk was C5 related, but TB size is TB size. it appears it's beneficial to both ETC C5 and F body cable driven, just different tables.

Any opinions on this?

[SOMhaveit]

On your 2000 SS, you have an IAC motor and the opening for the IAC motor is the same size on a 90mm TB as it is on the 78MM TB. The IAC effective area does not need to be changed. On the drive by wire cars like the C5, the TB does not have a IAC motor. It uses the TB butterfly to adjust Desired Air, so when moving up to a 90mm it is necessary to change the IAC area.

I have a 90mm on my 02 SS and did not change IAC area. Hope that helps.

[efizjb]

Thabnk SOM, I saw a lot about it for C5's (ETC cars), but it appeared they were making the point that it was the same for ETC cars to do, except a different table. Thanks for clearing it up. On to RAFIG!

[SOMhaveit]

Good luck!