With the A4 it is important to set the TPS voltage because it is a contributing factor to the pcms tranny decisions.

I actually tried it with the blades cracked open and was not happy with the idle and found the articles on drilling the bypass so I have actually tried it both ways so don't pretend I am closed minded here. I TRIED IT BOTH WAYS. Have you?? In which case who is closed minded??

 

Ditto.

 

Why would we drill into our $300 throttle bodys if they idle just like the stock one did. I didn't do any modifications to my edelbrock 58mm throttle body and the idle didn't change 1 bit from the stock throttle body. But according to you, even though the idle is fine, we should drill a hole in our throttle body just to duplicate the factory throttle body. I guess we should fill in the bores too, to get it back down to the stock 48mm bores.

 

No there is a performance benifit to be had from larger bores on a modified engine.

Can you tell me one benifit to only half utilizing the IAC circuit GM engineered for us???

 

I have a heads and cam 355 and when i had my stock throttle body on the car it would idle ok with out the A/C on. When i'd turn the A/C on the car would stall out. I then read on this board about enlarging the IAC bypass on the stock TB, which i did. The car would idle great with the A/C on or off. When i added my 58mm BBK TB and a new BRE cam the car had the same stalling issues. For a while i just had the blades cranked open and the car would idle good but i never bothered to check my TPS voltage. I'm sure it was way out of range though because my blades were really cracked open to get it to idle with the A/C on. I finally saw that people were drilling a new IAC bypass hole on their BBK throttlebodies and having great results with it. This last weekend i pulled my TB off and drilled out the hole and built a piece to go on the back side of the TB and seal off the IAC passage to the intake manifold. Now the car idles great with the blades cranked all the way closed.