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Thread: Target AFR Table?

  1. #1

    Default Target AFR Table?

    I have a 347 with a decent cam. X303, 224° at .050" on a 107°/117° centerline. I'm running a Terminator 550-406. I've been through a lot with this to get it right and I'm very close. The idle/start was tough to work out and I'm still tinkering there, but it's livable and really not too bad. I'm actually quite happy with the way this thing runs with one exception. Around 2500 RPM (give or take a few hundred either side of that) at half to 3/4 throttle, I get a "burble" and the car lays down. Let off the throttle and it cleans up & goes. Also, go to WOT, and it runs fantastic! The datalog indicates the car goes rich, 10:1 to 11:1. I've gone in and played with the fuel tables and found that they are actually pretty close as they are. I disabled Closed Loop Compensation and that seemed to help a bit. But when I disabled Learning, it helped a LOT. Still not right, but one heck of a lot better. I feel confident I could clean it up just fine by fiddling with the fuel tables and leaving both Closed Loop Compensation & Learning off. But if that's the case, and my question here, does this indicate that my Target AFR in the problem area is wrong? Isn't that what Learning & Closed Loop Compensation is based off? Thanks guys!

    By the way, I considered a bad WBO2 sensor, but I don't think so. It's possible I guess. But the incredibly expensive price for one prohibits buying one just to see.

  2. #2
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    Quote Originally Posted by CrimsonTide View Post
    But if that's the case, and my question here, does this indicate that my Target AFR in the problem area is wrong? Isn't that what Learning & Closed Loop Compensation is based off/
    Yes, read post #11: http://forums.holley.com/showthread....7370#post47370 (Learn Table - Read this thread, especially posts #2, #6 & #11.)
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS T/W 11R 205 heads, 232°-244° duration/.623" lift/114° LSA camshaft, 12:1 C/R, TFS R-Series FTI ported intake, BBK 80mm T/B, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 200A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, -6AN fuel system plumbing, Walbro 255 LPH pump, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/3000 RPM converter, B&M Hammer shifter, FPP aluminum driveshaft, FPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 M/T Street Comp tires.

  3. #3

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    I finally was able to get past my problem area. But I had to change the way I tune to get it done. I was tired of chasing my tail. The car is running and idling very well right now with just a little fiddling left to do. The way I got it close may be different than most. I completely shut off Learning & Closed Loop. I then set my Target AFR table to where I thought they should be. With a fairly big cam, I was surprised how rich I had to get it to be right. But the Target AFR table is where I made my changes until I felt the car was close to right. Only then did I turn on Learning & Closed Loop. When I made a change to the Target AFR table, I Transferred Learning To Base and smoothed the Fuel Graph. When I turned on Learning, I Transferred Learning To Base. Right now, Learning is around 2%, and Closed Loop Compensation is under 10%. Unless I change the Target AFR for some reason, this thing is about tuned. Today I'm going to work on smoothing the Fuel Graph a bit (it's close now), and make sure I don't hurt anything. My Target AFR table is NOT smooth! I don't care, I think smoothing that is way overrated as the car doesn't seem to care as long as the Base Fuel Table is close. Besides, if you look at some of the Target AFR tables Holley provides in their base files, they aren't very smooth either. So the lesson I learned is figure out what your AFR should be in your graph, and adjust from that. Smooth fuel, but don't worry too much about the Target AFR table being smooth. My 347 Ford now runs every bit as good as my LS6 does...if not better.

    I want to thank Danny & Andrew for all the help they have given me. You've been a Godsend to all of us who can get lost in all this.

  4. #4
    Join Date
    Dec 2009
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    Connecticut
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    Quote Originally Posted by CrimsonTide View Post
    I want to thank Danny & Andrew for all the help they have given me. You've been a Godsend to all of us who can get lost in all this.
    You're welcome, and thanks for the compliment. I'm sure Andrew feels the same way.
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS T/W 11R 205 heads, 232°-244° duration/.623" lift/114° LSA camshaft, 12:1 C/R, TFS R-Series FTI ported intake, BBK 80mm T/B, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 200A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, -6AN fuel system plumbing, Walbro 255 LPH pump, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/3000 RPM converter, B&M Hammer shifter, FPP aluminum driveshaft, FPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 M/T Street Comp tires.

  5. #5

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    Quote Originally Posted by CrimsonTide View Post
    I want to thank Danny & Andrew for all the help they have given me. You've been a Godsend to all of us who can get lost in all this.
    Thanks! I'm glad you're getting it sorted out. Andrew

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