Looking for some feedback and advice on setting up my Edelbrock 1806 thunder. I am certainly not a carb tuning expert and I know there are very knowledgeable people on this forum with these things. I have however wanted to get into this for a while and learn in the process.
So last year I splurged and got an Innovate dual wideband O2 in order to help dialing in my carb (and possible others) for a happy medium between economy/performance.
I did some reading up on AFR's and tuning and have played around and experimented with a few things etc. Came to the conclusion that the 1806 stock calibration out of the box was quite rich overall everywhere which was kind of expected from what I read. Anyway I ended up just changing metering rods to a 1452 (2 stages leaner on cruise and power from stock) keeping the 1426 jet and that certainly leaned things up as expected. The fuel I'm running is your normal lower grade E10 mixture which should have a stoich of 14.1 or so from what I read.
After some playing with the mixture screws this is what I'm seeing now for AFR's:
Engine seems to like the idle mixture set around 13-13.5. Just off idle drops to 12 or so (accel pump rich ?). Light to steady cruise when driving is around 13.5-14.5 now (perfect ?). However if I lightly step on the gas its leans up to about 16 or 16.5 briefly (too lean ?), a little more gas and it will return to the 14's or so. If I go up a slight hill same thing. If I punch it the AFR will drop to low 12's so I think that's still a bit rich. This changes a bit depending on what gear I'm in etc.
I find leaning or richening the idle AFR will also affect the cruise proportionately. Probably mainly cruising/driving on idle circuit from what I understand.
So my main question/concern for the moment is if hitting AFR's of 16 or 16.5 briefly during these cruise conditions is running too lean ? The car doesn't seem to hesitate or anything and it does richen up with some more pedal. I pulled my plugs after a fairly long drive and they were tan to slightly grey now which kind of confirms the leaner AFR readings in my opinion. I'm not too keen on melting pistons LOL
Any comments/suggestions are welcome.
Thanks in advance
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