If your kick-down cable or rod is properly adjusted then it should operate Independently of the presence of the supercharger.

As far as the jetting goes, I don't know the autolite system for jet numbering, but if your a/f ratio is in the 11's at cruise, then you need to lean out that circuit.

what is the af/ ratio under a load at part throttle, like accelerating up a long incline ? What is it at full throttle ?

Z.

The carb I have is a Holley 650 DP, and I would believe that I have size 45 jets.

The AFR is 11 at cruising and around 12 when accelrating slowly and appx the same when I have WOT.

Should I try going down 2 sizes?
What size do you have?

quote:

---

".............. The carb I have is a Holley 650 DP, and I would believe that I have size 45 jets.

The AFR is 11 at cruising and around 12 when accelrating slowly and appx the same when I have WOT.

Should I try going down 2 sizes?
What size do you have? ......"

---

I'm using a brand new k&n filter and have also tried to remove the filter, and the number did not change significantly.

As I mentioned above I'm using 67's on the primary sidel & 78's on the secondaries. That may be right for your engine, or not right. I'd go down two sizes at a time until you find the combination that works best for you.

Another thing to consider is lowering the floats 3-5 flats below the stock setting. I had to both lower the floats & reduce the jets before I was satisfied.

quote:

---

But it sure runs great with a leaned out system, just before the engine goes "poof".
Jim

---

I finally got everything where I want it to be.
I changed to 68 jets and the engine now idles at 13,5 and sits around 13 when cruising.
At WOT it is 11, which I feels is a bit high, but nothing to worry about – better rich than lean!

With the Paxton disconnected, the temperature variation has a MUCH smaller impact on the a/f ratio

Z. Ray

I can see the same variations here, however the temperature ranges are a bit different.

I did setup my a/f ratio when it was around 68, and when I ran the car a couple of days later when the temperature was around 90 it started running a lot leaner.

I have not tried without the paxton, but it would seem natrural for me that the more air mens bigger variations.

What are your A/F readings in the different conditions?

Seems to me when the air temperature is higher, the engine should be running richer, not leaner. But not in my case. Any theories ?

My theory is that the change in humidity, not temperature is causing the fluctuation in the a/f ratio.

The higher the humidity the less space there is for additional molecules of air and therefore oxygen. As the humidity increases there is less oxygen and therefore the engine runs richer.

In my part of Texas, and elsewhere for all I know, when the temperature is low in the mornings, the humidity is high. When the temperature is high in the afternoon, the humidity has dropped. And (here) it's the very low humidity of 5% to 15% that is allowing the increased oxygen in the air.

Z. Ray

I checked today and it seems like humidity are the only factor for me.

Today it was a dry day and the engine ran 0,8 points leaner than last day. The temperature was almost the same, appx 68.

Z.