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

Rock,

With out I sensor I was flying blind. I limited the changes to one a week to 3 weeks, which takes a long time to collect the data and verify the results for another week or two, so about 3 weeks per change. As I got the air bleed closer and the other carb changes dialed I had to increase timing to smooth out the results of the extra fuel. My 1920 Holley is so punchy and sensitive that when I crack the throttle plate it responds like a race car. The engine is extremely peppy and the throttle is sensitive. That is how I get the wheel spin with a 8 3/4 posi. A instant hit of torque. With the initial at 16 degrees there is no bog like before when the air bleed was plugged. In fact, the recurve feels even better with the red MOPAR spring and super long black secondary spring on the 15R governor. To add a little more punch I have the VC-208 vacuum pod set at 2 turns for an extra advance hit at light throttle settings to deal with the extra fuel now that the emulsion circuit is working. The throttle is super sensitive to position changes at all speeds now. No lagging or dead zones. As a result I am finally averaging 25+ mpg. It would be fun to take it on a trip to what I could get.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

I am going to put one in the Daytona. I guess it's time for us old guys to move into the new millenium, huh?

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Official Cookie and Mater Tormentor.

Howdy 'zilla,

I still can't believe it...my running is fixed. I am sitting around feeling as if I have nothing left to do on my slant! Each to his own risk acceptance, but after having bought my Powerdex from a local store darn if I wouldn't buy a new one off ebay for about $75 to #100 dollars less. I realize there is a Powerdex disclaimer that no warranty applies to units not bought from a dealer, but there is very little to go wrong! If the sensor is bad, it is $79. If the little integrated readout box and sensor is bad on delivery to you, you should be able to get it replaced by appropriate squawking or prior agreement, and if it works once, I don't see why it wouldn't just keep right on working. The little box is about the size of 3 1/2 inch diskette (old guy device) and fits right over my sun visor. Man, why didn't I get one long ago!

Oh, thanks again Ted, good advice there and I am gonna move to 16 degrees BTDC too. I am using some of Rob's (DI) springs and think I settled on the same pair you are mentioning.

rock
'64d100

Rock on!

WB stuff is a godsend. Once I got it in, it was much easier to see what carb is DOING. Now I need to get one more jet changed and should get it right.
Doing 20mpg city too for a 2.2L carb with 3spd auto in a caravan.

Cheers, Wizard

Great stuff, Rock. Yeah, I need to move beyond NB O2 on my cars...

Lou

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Home of Slant6-powered fun machines since 1988

I just picked up an LM-1 kit from Innovate Motorsports. They can be had super cheap now as the LM-2 are becoming to new cool thing. I got mine off eBay for $250.00 express shipped. I just got it the other day and haven't use it yet, but I am excited just looking at it.

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1969-1/2 Dodge Super Bee A12 (440 Six Pack, 4-spd, Dana 60)
1974 Plymouth Duster 360 (4-spd, 8.75")
1973 Plymouth Duster (225, auto, 8.25")
2001 Dodge Ram 1500 QC 2wd (5.9L, auto, Dana 60)