finally got a wideband.how do my #s look?

[jdsduster]

408 stroker 508/510 hp & tq. carb is a atm 750 dp 76/87 jets.cam is hyd flat tap.cruise at 40-50 is 12.-13.thinking of 75 jet there.wot from dead stop 10-12 until im in 3rd gear at 5-6 on the tack,at that point its 15 on the gauge.wideban tuners out there,whats you opinion? car has 8-10 " of vacuum with a 6.5 pv

 

[jdsduster]

wow not one answer

 

[1MeanA]

15? Way too lean. It should be 12 1/2 to low 13s at WOT.

 

[66Valiant528]

I gotta say you should probably plot your ignition advance curve to see if you can add or subtract some spark where you are fat during hard acceleration. If you have dialed in for max total timing you can still mess with the curve. You need more jet for top rpms. Before you get into messing with air bleeds make sure your timing is optimized.

 

[mopowers]

What do the plugs say? Focus on that instead of tuning to a particular number.

 

[jdsduster]

I gotta say you should probably plot your ignition advance curve to see if you can add or subtract some spark where you are fat during hard acceleration. If you have dialed in for max total timing you can still mess with the curve. You need more jet for top rpms. Before you get into messing with air bleeds make sure your timing is optimized.

my timing is 22 with a quick curve 0f 12 to 34 total

 

[jdsduster]

15? Way too lean. It should be 12 1/2 to low 13s at WOT.

it was until the of the run thats when it jumped a little toward the higher end

 

[TrailBeast]

wow not one answer

Just a FYI, don’t count solely on the AFR numbers.
What your engine wants and what the gauge says can be somewhat different.

 

[pishta]

leaning out on the top end sounds like fuel supply issue. Yours sounds fat all around. Max power should be 12.5-13.1 depending in your gas (E10 or straight gas, E10 likes 12.5 as gas likes ~13) cruise is your choice between high 13 and low 15. if you can keep eye on EGT and pinging, you dont need stoich for cruise. Nice thing about widebands is that you can make a change and actually see the results in real time. drop a jet size and see what happens. If you can smell gas at warm idle you are too rich.

 

[forphorty]

As pishta said above , I suspect that lean out in high gear is fuel delivery.

 

[jdsduster]

thanks guys.i thought it was close just a bit lean on the top end.

 

[MadScientistMat]

Agree that the final 15 is likely a fuel pump or delivery problem. It also sounds like the rest is a little rich: you may want to aim more for 12.8:1 or so at full throttle. I would try a little smaller on the main jets.

 

[mopowers]

Agree that the final 15 is likely a fuel pump or delivery problem

Or maybe a wideband in need of re-calibration.

 

[MadScientistMat]

If the reading happens consistently at a specific condition and looks plausible everywhere else, I would not suspect a calibration issue.