Adjustable AAV

[jrwilson]

My AAR allows a bit too much air in at startup causing a too-high idle.

Is there any guides on how to convert an AAR to a variable adjustment? I'd like to tune it to open a bit less.

[boyt911sc]

Jeremy,

Maybe you meant AAR (auxiliary air regulator) instead of AAV (auxiliary air valve)?

Tony

[jrwilson]

Yes, sorry - get these acronyms mixed up.

[911 SLANT]

Talk to Ian Carp. I believe he has one on his 3.0 Green Kermit car

[83_Silberpfeil]

This two-part video series shows you how he modified his AAR for 81 SC. Don't know if that's the recommended way, or a master tech approved, etc, but it is how he did it.

Each video ~ 10 min, very easy to consume. There are also 160 other 10 min videos on various topics/projects on his 81 SC on his channel.

Part 1:
https://youtu.be/amC1UBQKZE8

Part 2:
https://youtu.be/kq2U1qGNNww

Originally Posted by jrwilson

My AAR allows a bit too much air in at startup causing a too-high idle.

Is there any guides on how to convert an AAR to a variable adjustment? I'd like to tune it to open a bit less.

[SkiVT]

No idea if this works but see the adjustable picture in this thread. Seems to me you still have to take the AAR out and reinstall for each adjustment, which is generally a pain in the ass. So I don’t see a big pick up with the adjustable part over just knocking the pin each time.

https://forums.pelicanparts.com/porsche-911-technical-forum/112138-aar-good-bad.html

[jrwilson]

Hmm, would I knock it in to make the hole smaller to drop my high idle? Or pull it out?

[SkiVT]

Yes knock in for smaller starting size of hole. If you drop idle too far, you need to knock that pin much further in to get the cap on the other side off. Then knock it all the way back from the cap side. Then start all over knocking it in to your preferred idle. Pain in the ass overall but it works.

My idle goes to 1700ish and then drops over time. It’s annoying relative to how new cars work but apparently is normal for an SC if that’s what you have. So how high is your “too-high” and is the adjustment effort worth it?

[jrwilson]

My high is 2000-2100RPM, which is a bit too much.

I note there's two pins - which one am I knocking in? The smaller one?

[SkiVT]

On the right side by the 28th day of this pic. Cap is on opposite side.

[boyt911sc]

Jeremy,

Do you remember this AAR I showed you when you came to visit me in late May 2023? Your AAR needs to reduce its “aperture” (opening) at room temperature. Look through the hole and if you see a half-moon shape, that’s a good starting point.

I attached several pictures for your reference. I refrained from making any comment on the old thread attached by SkiVT and specially the YouTube video of the Japanese guy that fixed the hunting idle. You got to be a gullible person to believe it.

This is the rear view of the AAR.


This is the front view of the AAR. If you push the plug/post IN the opening gets smaller. If you pull plug/post OUT the opening gets bigger. See the direction of the arrow.




This is the side view that shows the cap. In SkiVT’s reference showed the threaded bolt was mounted on this side (wrong side). It is a very old thread so let it sleep.


This is a show and tell sample of a modified AAR. The rear end was cut just to show the inside. For the real one you don’t cut it open.

Tony

[356911930]

Hi Tony, if you have a hand throttle (1976 930) a you just remove the AAR and use the hand throttle?

Thanks

Rahl

[PeteKz]

Tony won't like this reply, but that's what I did in my 1973.5. No more auxiliary air system (after the engine is warm, it's just extra baggage and more crap to leak or go wrong). I can also see and get access to the ToD without all that plumbing in the way.

[pmax]

Originally Posted by PeteKz

Tony won't like this reply, but that's what I did in my 1973.5. No more auxiliary air system (after the engine is warm, it's just extra baggage and more crap to leak or go wrong). I can also see and get access to the ToD without all that plumbing in the way.

The AAR isn't OEM anyway in your 73.

Did you dump the rest of the "claw" as well in the transplant ?

[PeteKz]

But I have a 1980 RoW engine and CIS, which had all that crap. Yes, I got rid of the metal Y and AAV and AAR, etc. I just use the hand throttle for a minute or so.

[pmax]

Way to go .... the addition of the AAR as CIS developed ... I get that given that automation allows a hands free warmup, just start up and drive plus removal of the hand lever and associated hardware which is arguably a manufacturing simplification, cost saver and weight reduction but the AAV, why ?

[PeteKz]

Emissions. Later emissions tests included the warmup part of the cycle.