The Stovebolt Site Forums The Shop Area Driveline Stall speed.

Why and how is it important?

Street vs racing.
(All responses must be six words or less like the question, I'm assuming.)

"The velocity below which an aircraft will descend, or 'stall', regardless of its angle of attack."

Sorry about exceeding the word limit.

Uh, oh: I think I am off base with my reply, above (see below):

"In other words, stall speed is the engine RPM at which the torque converter transfers the power of the engine to the transmission. In the real world, the torque converter's stall speed roughly equates to the clutch engagement point on a manual transmission."

It still exceeds the word limit - sorry, again.

...vs flying...

Torque converter stall speed is governed by the amount of torque the engine has. The same torque converter behind a Chevrolet Vega 4 cylinder will stall at relative low rpm, take the same Vega converter and put it behind a 454, it will stall at much higher rpm. The vega converter was to go to back in the day just for this purpose. The converters that are sold as "3000 stall speed " will only do that if the engine has the power, don't expect a stock 350 to stall up that high, unless the converter is made with junk parts. My racing converter would stall about 2700 rpm with foot brake in my '67 GTO, same converter in my dad's 1000 lb heavier wagon would stall about 3100 rpm, better brakes, more weight, and higher torque. The really good converters, $800 + , will work at relative low rpm for everyday driving, but still stall up when asked to. The cheap ones, slip most of the time.

The tight converters, where stall speed is low ( 1600 - 1800 rpm ) are much better on fuel mileage, less slip so more of the power being made is being used. The lock-up converter was a way to gain more mileage and mimic the manual transmission clutch, full locked-up with zero slippage.

To many words ?

Just a few.

A really neat setup is the POB switch pitch Turbo 400. I used to race with one, had a switch to change stall speeds. High side was 2400 or little more, low side was about 1800. GM used them in the big heavy cars with low rear axle ratios. They went to the high stall at idle and used the extra rpm to get the cars rolling, once up to speed, the converter would switch. Passing gear would drop a gear and switch the converter for extra power. My race car ran 2 mph faster then with my custom made expensive converter due to the low stall speed!

If my 250 inline six had enough power to spin a turbo 400, I would put one in.

oil on clutch pedal 3mph stall

Clever deception on word number restriction!

Will not move before stall speed?

Where'd Ron go? Come on man!