I'm trying to figure out which ones have this opening on the back side of the IAC port which allows for the idle air to go to the plenum instead of the idle air ports like in this pic
http://members.***.net/chipsbyal/pag...ndex.html#rear
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I've read that the Holleys do not, but have heard bad things about them quality wise, looks are great, but the functional quality was not.
BBK I read one post that it did not, but the borrowed BBK I have does have that opening..maybe its an old one??
Any others?

The stocker is sealed off from the plenum so that idle air is evenly distributed to all cyclinders and I have a borrowed BBK that idles terrible and very eratic, but has holes in the blades instead of the single hole inside the IAC port that may be needed to lower IAC counts at idle.

 

I have the holley 58mm that does not have it.

 

My new Holley 58MM has a very large hole compared to the one you drilled. Im working on hosting a few pics.

 

Ok here it is.

Rear:


Front:


Bottom:


Rear and Bottom:



Maybe Holley has changed things. I know others have complained about quality, but mine is a very high quality piece. Im very impressed with it

 

Hey Josh, its hard for me to tell in that pic if there is a hole all the way thru the IAC passage to the front of the TB from the first pic labeled "Rear", that hole thats just smaller than your pinkie finger is normal but I can't tell if there's a pin hole straight thru as thats the one everyone is talking about in my other thread. The hole in that pic would mate up to the IAC passage hole in the plenum, and let both metered air thru the IAC and the unmetered air from the pin hole (if it exists) into the idle air passage in the plenum.

 

Josh, where did you get that newer Holley and how much? It looks like the IAC passage will finally seal up against the intakes IAC passage like it's supposed too.

 

It isnt through to the front. I thought that some of these didnt have a hole down to the IAC passage at all. Its hard to tell by these pics and descriptions what all is being talked about.

So you guys are actually talking about letting unmetered air through the IAC port. Hmm, I dont know if I would want that

quicksilver97ta: I got it from GMR speed. They had the best price I could find, and my budget was already blown at that time

 

No, they are not. It's still metered by the MAF, it just doesn't go through the IAC. The stock TB is set up the same way, with a hole to allow some idle air to get in past the IAC. Calling it "unmetered" air is really not an accurate term.

Here is a picture of a stock TB. See the hole between the two throttle blades that goes strait through? That is the hole they are talking about. It allows some idle air to bypass the IAC.

 

TraceZ is correct, that is the hole I was talking about..no big deal if its not there, if I mount it and then decide if it needs to be there it can always be added later if the IAC counts are too high all the time.

So does anyone know if Holley redesigned their TBs as compared to the ones a few years ago that had all the problems that can be found in numerous posts???

And the main thing I am concerned about for this post is whether or not different brands have the IAC port passge opened to the plenum like in the pic in my original post?? I do not want that....Holley's do not, but what about newer BBKs and AS&M?? or any others.

 

 

Ok, the Holley looks very nice, but still unsure if the quality problems seen a few years ago were address, no one seems for sure.

Any BBK TB owners know if the IAC passage is open to the plenum on newer models?

 

I've got a BBK from like '98 and it doesn't open the IAC to the plenum. Didn't have the hole everyones talking about here either, but it does now.