Certainly I have no more and most likely less cash than anyone trying to play engine tuner, but after several years of pro and con on this forum, I bit on a Powerdex AFX wideband o2 apparatus for air/ fuel ratio. My final cnoice was made on what to my needs was the superior readout...it's big and clear.

Well, even in the $300 range it might be the best tuning device I own. I was faced with a haunting feeling I was just a little away from my best performance tuning state with a Holley 8007, even after a year of recurving and driving and testing. Well, I was right. After installing the bung and sensor it only took one morning of tweaking and driving to maximize the state of tune. Only if you had spent a year hearing your spouse whine about 'are you going to mess with that truck again this weekend" can you appreciate getting it right in a few hours!

Thursday I PM'd a few tuners and described what I was having happen at what ratio. Those west coast guys are pretty good! In essence I didn't think I was too lean, and Ididni't think I was too rich at idle, but I had the hint of a bog on stomping it. Changing initial from 10 to 14 degrees fixed it and also shifted AF ratio to 13.4 to 14.2 at WOT...who woulda though you would shift ratio by changing timing 4 degrees! Caveat: I am working with a 9.4 CR, not stock.

It made me go to one of my project notebooks and re read the thread we have on "Holley 1920 air bleed/idle transfer slot mods"...very useful thinking there from DI and Juan and Ted on the idle transfer slot and butterfly position in Holleys, even though they are talking 1920 as opposed to my 8007. Now my AF ratio while rolling along at 35 to 75 is 15.8 to 16...lean but not too lean.

Since I am out of things to do I think I wlll make some Emsvitil like plots of AF ratio against where vac can tweaks kick in. I don't plan to leave the sensor in all the time, but have found I can rent the setup locally a few tuners, and probably get most of the expense back. Man, what a good tool, if you ever waffled on getting one.

rock
'64d100