So I have my AED Holley 750 HP body double pumper all tuned in. Idle, transition, secondaries, and WOT are good.

My primary main circuit is being strange per my AFR readings. Running 72 jets. They come in at 2500 rpm rich at 13afr and go lean after that. Almost to 16 afr. And that’s with a 10.5 power valve.

too rich at the beginning of the main circuit then goes lean at it approaches power enrichment.

will a small IAB stabilize this circuit? I’m running .31 IAB’s. Online research conflicts. Some say bigger bleeds. Some say smaller.

mild cam 383 stroker

 

Sounds like you are looking at them wrong . .031 sounds like a hsb.
hsb inside, iab outside bleeds.

 

On the last paragraph, I meant high speed bleed instead on IAB. Would reducing the size of the HSAB stabilize the primary circuit?

When I cruise at 2500 rpm, I’m rich at 13 AFR but lean at about 3000 rpm when I cruise at a faster speed.

 

My experience, if your just cruising 3000-3500 up, its effected primarily by the main jet.
Down by off idle to 2000ish is idle circuit.
I would put 78 jet in the primary and see how it responds 1st.
If it gets better at 3000 then reduce ifr a bit too lean it down low.

 

I’m running 72 primary.

 

Ok. Put a 78 in it and see what it does.

 

Fixed. My cruise AFR was rich at 3000 the leaned out fast before my 10.5 PV opened. I fixed it with a smaller HSAB. Dropped it too .028. Flattened the curve nice. Leaned out the lower end of the primary main circuit and richened the higher end of the primary main circuit just before PV enrichment. I may even be able to drop to and 8.5 PV.

My off idle was a hair rich but perfect at low speed transition cruise. Went from .031 IFR to .028. Much better. Dropped from .075 IAB to .073. I may drop to .070.