A friend of mine just built a 350 for his ride. Its nice.
He cammed it up a bit with a Crane cam that starts making power at about 3200.
What he forgot to do was buy a converter that has a higher than stock stall.
He has a stock converter in this.


I'm trying to explain to him the reason for the excessive idle bog when shifting from neutral to drive. It just bogs way down, from about 1200 rpm or more to barely 5 or 600 when he shifts into gear.
I told him he needs a higher stall converter.

He wants a reason described to him more technically and I can't articulate the nuts and bolts of it, other than, I can see he needs one.

How would you guys describe it?
In other words, why does this requirement exist when it doesn't exist for a manual trans?

The torque converter need more "slippage" built into it. If there was no slippage at all it would be like dumping the clutch at idle. The engine stalls.

Just explain to him he'll be paying for a rebuild on the tranny with a stall converter soon.

The stall converter (a fluid coupling) is made to slip and lets the rpms come up (spin) faster dependant on the fin angle (angle/pitch changes stall) to let the motor idle and get to its torque band faster to move the car more efficiently. Stock stall is low due to the stock cam used (small), more lift and duration (big) more stall.
If it's dropping that much just putting it in gear it needs a stall.