Guess what? After 7 more drives after re-installing the A/F kit, it died,,again. It is now back at FAST and they say that they have never seen this trouble with one of these units before. Last time they said that they did not find any issues with the unit and it was due to my wiring. But when I told them that I had power at both of the 12v leads, they said that it was still by wiring. So I wired it back in and it ran fine for a short time again. Anywho, the same problem happened again this time as it did four weeks ago. So I am waiting on them to call me and it is still under full warranty. I am waiting patiently to see if they find anything wrong with it this time. But during the seven drives, I was testing the cams/squirters trying to get my off idle accel and my cruise-WOT A/F ratios to fall into place. I did not finish before the kit took a dump, but what I did notice was that the different pump cams that I was using sure do make a huge difference in the A/F ratio. I was running a pair of Red cams and from 50-55mph cruise to WOT, the A/F ratio dropped to 12.5 for a second and then leaned out to 13.0 at my shift point. I wanted to lean this out to the upper 12's and started changing out squirters. The squirters did not do anything to the A/F number (secondary side: 25, 31,35,37) so I started swapping out cams. I tried swapping in the secondary cams and retesting and found a minor A/F change from red, black, and pink which all gave me about a 12.0-12.2 A/F reading with the red primary cam. So, for the fun of it, I swapped out the primary cam to an orange and found a huge A/F change that showed a dip to 11.0 at the cruise to WOT. These changes do reflect the Holley pump cam chart that I have been referencing for the past 3-4 years. I know that there are a few of these charts on the internet and now I have proof that I am using the correct chart. I am finding out that I need the smallest black cams to keep my cruise-WOT spike in the upper 12's. I am now using a black/.037 on the primary and once I get the kit back installed, I will be testing with the black cam on the secondary side with a 031 squirter. I am hoping that this change gets me into the upper 12's but if it does not, then I am going to test with a scondary linkage change that Quick Fuel provides with their DP carbs. I am currently using the linkage that allows the secondaries to come in at 40% throttle and if I have too, then I will delay it with the 60% throttle link. I remember when I ran a vacuum secondary carb that this combo liked the heaviest brown spring. Maybe it will like having the secodaries coming in later with the 60% delay too. I will check back in when I get my A/F kit re-installed and I have more tuning time. If any of the members have some A/F numbers to provide along with their pump cam tuning, please feel free to tell us how the tuning came along.
