60 ft blues

[Steve Wood]

I would think your low gear fueling A/F should be 10.9 or so...

[Tim Hensley]

Low gear is 11.0 today no help on 60
But why dose the rpm go flat?
It is increasing in mph but the converter is doing something

[1 RARE T]

Is that not the 1-2 shift follow soon after by the 2-3?

[Steve Wood]

if the car is rich, it will make the engine fall on it's face.  That is why I mentioned it.

Looks like the converter is absorbing the rpm until you take your foot off the brake.  It takes off when the car launches if I am looking in the circle you made.  That would not seem abnormal to me.  Either the converter slips or the car has to move

[Steve Wood]

Did the transmission flare on the shift to second?

[nocooler]

What chips in the car? Do the plugs and wideband agree?
Does it hang at the same spot if you leave easier?
I assume you’ve verified trans fluid level?

[Steve Wood]

I think that is what the Rare One is talking about.  Looks like it slipped thru second and picked up again in third when looking at the mph behaviour

[wmsonta]

Tim, I like your converter. What diameter? LU? Built locally?

[Tim Hensley]

This takes place before 1-2 shift
Running 6.1 chip and plugs do agree with wide band but have not pulled them the last 6 passes.
AF run around 10.8To 11.5 after I made a low gear fuel change
Trans fluid is good 700 filter deep pan
No matter what rpm or boost pretty much the same. Always goes rich right there spraying Alky   Left Alky of one time it left at over12 AF and has the same flat spot.
I don’t know what flaring is but I don’t think so, this happens befor 1-2 shift
Steve your right throttle is WO I release the break RPMs climes then it go flat then climes to thi 1-2 shift falls back to about Sam rpm climes to the 2-3 shift

[Steve Wood]

I was looking at the flat spot in the mile per hour when it hits second, then it seems to ramp up a bit when it hits third. There is a bit of a "bulge" in the rpm rate of acceleration that flattens out around 5000 then picks up again.  Maybe the wheels spun? 

[Steve Wood]

It will also be difficult to avoid a rich spot when the alky starts to spray.  The ecm cannot correct fast enough to hide that in my opinion

[wmsonta]

Ok, here goes.

The flat spot. I am used to see slightly different versions of a flat spot in data logs. Tim, you will be really unhappy if the flat spot goes away. It is the converter going from high torque multiplication ( if LU, probably 2.0+) to its highest efficiency (0.92-0.96, probably). Commonly called stall. You can also see the flat spot after the shifts. The rpm goes low enough to get back into multiplication . With turbo/heavy nitrous cars the stall changes with engine torque.
I worked with a 3800# bbc Camaro. The owner used a brake and releasing the brake activated the nitrous. The stall w/o NO was 3500, with nitrous the stall was 5500. The car was 1.29-1.31 short.

I did not see a rpm flare on the shift. Something I have seen several times. I have never seen one where I wondered about it. If it is logged.
I HTH.

edit-I like the converter.

[reality]

https://www.converter.cc/Yank_SS_Series_Converters_p/ss-buick%20gn.htm


https://www.converter.cc/STR_Chart_s/82.htm


Something with about 2.4 STR. IMO.

[Grumpy]

What setting on the alky ?? single or double nozzle ?

[Tim Hensley]

The converter is a 9.5 from Lonnie at Extreme Automatics’s.
So the flat spot is good?
I’ve been try to get the cars time slip to be like the Wallace slip, it’s close.
Wheel spin is hard to control some times,hopping the new MT PBR will help.
Alky is set at Julio base and between 6-7 , single nozzle.
 Know for the converter I’m pulling it out to possibly make it stall a little higher to help the short time and tighten up the top ( got 10% slip through the traps).I’m open for help here.