I recently switched to E85 and added 2 extra 1600cc secondaries to my Ground Zero Manifold. I got it tuned pretty good for 28lbs, but cannot seem to get rid of a bog that happens at 36% duty cycle where the car goes dead lean. It is very evident in 1st gear, but still shows up in the others. I am assuming this has to do with the secondaries coming online. The reason I believe this is that the bog follows injector duty and not any specific cells in the map. I have toyed around with the injector lag, but it doesn't seem to do much. Does anyone run this setup and have any pointers?

Here is a log in 1st gear if anyone wants to take a look.

I will also put up my map if anyone wants to look further.

www.radkinsrx7.com/Bog.txt

 

Bump

 

Look at your log in chart trace format and you will see that it is not leaner but richer than around it. Looks like bad fuel tuning to me!
You also have AFRs going to 19 while still using fuel. Maybe your WB is bad or not correctly hooked up?
Have you tried this type of real analysis?

 

I'm not sure I see what your saying. I have looked at it in chart mode and even when I look at yours the AFR's look leaner (yellow line)?

If I add tons of fuel to that cell then next time it gets hit when the inj duty is not 36% it will be pig rich and this bog will happen in some other spot. Does that make sense? I have been chasing it around adding fuel and it never seems fix it, that why I was thinking it was an injector staging issue.

Also I have an exhaust leak that I cant seem to get rid of so that WB reads a little lean.

 

This is what you said. Look at where I stopped the log at 37% DC and the fuel there is richer than just before and only slightly leaner than immediately after the point but then it leans out as rev gp up.

The AFRs are leaner when they go up and richer when they go down on this chart.

If this was mild acceleration than most of it is too lean.

 

I went out tuning tonight and realized there is no way to correct this problem with just fuel mapping. No matter what I did, during the transition the afr's would go deep in the 10, then swing to 17. Sometimes it would do it soo fast the log wouldn't even catch it. After messing with it for a while I was able to get it to smooth out by adjusting the Secondary Transition ms in Settings 5. Now the AFR's are really rich, but pretty stable. I ran out of time, but Im pretty sure this will do the trick.

 

If you're dumping waay too much fuel during your initial rough-in then you may be extinguishing the combustion at that cell...which means the oxygen isn't consumed during that combustion event, which means there's a lot of excess oxygen read by the sensor. So it'll read lean when really the problem is that you're too rich.

 

^^Exactly.

Too much fuel causes a misfire and the result is a lean AFR shown, when in fact it's too much fuel. You will just have to mess with the transition until you can get it to even out and not dump so much fuel when they first come online. This will be difficult as you're opening up 6720 cc worth of fuel injectors on at the same time.