EFIDynoTuning Forum

patricktjms wrote: ↑2021 Jun 14, 15:23 I have had the same issue for a year now and can't rid my car of it. Same bog. Manifold volume doesn't do anything. I also leave at about 2000 rpm. Would love to find a way to richen with tps rate of change or something like that.

I always run in open loop all the time and the car will print time slips, but the bog is tricky for reaction times.

I had already tried Air_Man_vol previously, and it helped a little but didn't solve the issue. So I set the base fuel table to .875 for everything above .40 perload and set 320A to .40 which forced open loop and enriched fueling when I come up on the converter, but it will use the O2 for idle and driving in pits.
Keep in mind this is for a drag racing tune, only intended for WOT, not street driving.

What is showed me was that my fueling was way off in lower MAFV points, with load on the engine. The converter stalls so high, I'm either at 1v or 4v+ except for about one second on launch. I had not accurately adjusted the MAF points from 1v to 4v and I was lean on launch because of it.

The car seemed better after adding more fuel, but I only got one pass in after the MAF adjustment so I still need to make some more passes to confirm the MAF transfer was my issue.

On a side note... seems like we trying to accomplish the same thing with our tunes. What changes have you made in your tune to try and improve consistency?
I'm looking for things like making spark act like a fixed distributor with timing full in from launch thru the entire pass.

I seem to remember a post in the old forum saying a Spectra FD22 distributer was the equivalent to an OEM replacement.
I can't remember if it recommended replacing the pickup with a Ford pickup, or using as-is.
I've been running one as-is for a couple years now with no issues.

New motor in the bracket car and I'm having some issues with a bog off the line. It seems to get worse with poor air conditions.

I think it may be caused by being a bit too lean off the line from the initial hit to about 1-1.5 seconds out.

I don't know if it would make a difference in what to adjust but I'm coming up on the converter to about 2300 rpm, so the initial hit isn't from closed throttle, it is from about 1.65v TP.

Do I reduce Manifold Volume or TSEIF or both in CBAZA to add pump shot?

Since the car is a track only car, would there be any down side to adjusting 320A so I once I come up on the converter I am in open loop?
My thinking is, if the fuel is already there, it won't need as much enrichment and may be a little more consistent.

When looking at data, my RPM data is not very smooth. 2nd and 3rd gear WOT pulls show a repeated 200 rpm drop or increase between data points while accelerating. I did replace the original distributer that had worn bushings with a Spectra FD22, but I did not see any difference.

Is this just the nature of the beast, or should the RPM trace be consistent and smooth?

I'm not sure what you are looking for in a converter as far as stall, but I purchased one off of EBAY a few years ago that I was happy with for a little extra stall on the street, and was till going strong with over 200 quarter mile passes on it.


2200-2600 stall for AODE / 4R70 (Remanufactured)
$165 with free shipping

Seller was "torque-converter", and I just checked and he still has the same converter listed

Just so you know... the answer to the registration question isn't acceptable if capitalized.

The new forum looks nice and clean, nice job!

-Mike