mike13

iTrader: (27)

1999 firhawk
T76 turbo
circle D 3200 stall
3.73's

I was doing some datalogging today and comparing engine rpm/ mph/ tire size/

2nd gear pull to redline showed convertor slippage of approx 800rpm @ redline is this normal? This was a pull to redline and let off.

Would the percentage of slippage decrease in 3rd and 4th if I continued accelerating in a 1/4 mile drag type run?

DREAMZ28

iTrader: (1)

I would think the slippage would increase through 3rd and 4th because of the higher load, but dont take my word for it I'm still learning things.

mike13

iTrader: (27)

I thought that too but I'm questioning if maybe there would be less slippage on the top of 3rd and 4th since the rate of acceleration would be less? I don't know, torque convertors are like black magic to me.

DREAMZ28

iTrader: (1)

Same here.

Guess we just gotta wait until the forum experts drop in and shed knowledge..

JonCR96Z

iTrader: (33)

Are you using an accurate tire size, as measured by the roll out.

cablebandit

iTrader: (37)

lock the converter and then you can see exactly how much it is slipping.

mike13

iTrader: (27)

I don't think my lock up clutch would hold,

TC76/ 3200 stall not good for standard lock up clutches.

Yes tire size/ roll out is correct.

TXCAMSS

iTrader: (60)

If you are data logging using HPT or EFI live, you need to log transmission input speed and engine rpms. You can import that data log to an excel file and calculate the efficiency throughout the run. If you don't have much gear in the rear you may be at a lower rpm in 3rd gear and seeing the most slip possible. Most measure the efficiency at the top of 2nd gear unless your gearing is optimum and at redline going through the finish line. I hope this makes sence.

If that is a 2 or 3C it is a very efficient converter.

JonCR96Z

iTrader: (33)

For his car trans input speed is just calculated not actually measured. I've setup some PIDs for my stall using trans input speed, but there is no way that the info was correct