Weight and the converter

[Joe DeMarzo]

Does the weight of a car change the stall of the converter? For example if a converter stallls at 4800 in a 3400 lbs car and you remove 200lbs does it change or stay the same?

[63corvette]

The stall of the converter has to do with the horsepower supplied by the engine to the converter and nothing to do with the weight of the car until the car is launched when the converter starts to do its work.
My 2 Cents
Rick Cates

[Billy Nees]

Originally Posted by 63corvette

The stall of the converter has to do with the horsepower supplied by the engine to the converter and nothing to do with the weight of the car until the car is launched when the converter starts to do its work.
My 2 Cents
Rick Cates

Yes, but even though the flash rpm would stay the same, once the car is moving the converter would "act" tighter in the lighter car.

[Ed Wright]

Originally Posted by Billy Nees

Yes, but even though the flash rpm would stay the same, once the car is moving the converter would "act" tighter in the lighter car.

Sho 'nuff!

[Bob Bender]

Originally Posted by billy nees

yes, but even though the flash rpm would stay the same, once the car is moving the converter would "act" tighter in the lighter car.

x2

[Adger Smith]

Billy, Well said!
It will also change the way it works if you change gear ratios. A deeper low gear will make it act like it is tighter.

[Todd Boyer]

Originally Posted by Billy Nees

Yes, but even though the flash rpm would stay the same, once the car is moving the converter would "act" tighter in the lighter car.

Is this because the weight of the car affects the 'force' the converter 'sees'? Or that if the car is heavier, the converter is 'forced' to work harder and will therefore be looser?

[Billy Nees]

Originally Posted by Todd Boyer

Is this because the weight of the car affects the 'force' the converter 'sees'? Or that if the car is heavier, the converter is 'forced' to work harder and will therefore be looser?

The converter would be loaded for a slightly longer period of time in the heavier car. (200 lbs heavier, same car)

[Mark Yacavone]

Originally Posted by Todd Boyer

Is this because the weight of the car affects the 'force' the converter 'sees'? Or that if the car is heavier, the converter is 'forced' to work harder and will therefore be looser?

If I understand what you're asking, the answer is > both.
A good running Powerglide car does so, in spite of having such a high 1st gear ratio, because the converter is forced to "work harder".

As another example pertaining to weight; A street and strip car with a high stall converter,cruising along on the freeway, comes to a hill or rise in the road.
The effect of the hill is that the car thinks it's "heavier" and the RPMs will rise, while maintaining the same MPH.
You've got to remember,unless it's got a lock up clutch it it, it is a fluid coupling

[Chris Hill]

Originally Posted by Mark Yacavone

You've got to remember,unless it's got a lock up clutch it it, it is a fluid coupling

This is something that has always made me wonder. What are the actual physics involved to cause a converter's stall?

At least in our cars, the engine goes past the torque peak then settles down at a lower torque value for flash/stall. And keeping everything equal with gearing and weight, in good air it will flash at a higher rpm with increased torque.