about torque converter stall

[Nacho-RT74]

I have known about the way to get the torque converter stall is fully pressed brakes and that open throtlles untill engine doesn't rev up more.

what about if you are going down a hill, on 1st gear and check how much RPMs tach shows when car is being hold down by the tranny?

[Musicman]

I just start from a dead stop on a level grade... put it in gear, mash the pedal and take note of where the tach is at when the car takes off.

[grdprx]

Another silly question from a novice.  What exactally is torque converter stall?   Is it as basic as it sounds?  I don't know how it relates to a build...

[FLG]

The stall speed is the RPM in which the power from the engine starts to get transferred to the wheels. Each build will work better with a specific torque converter stall. You want to be in the RPM range where your going to be making most of your power. Do a google search and there are plenty of very in debt articles.

[Nacho-RT74]

I just start from a dead stop on a level grade... put it in gear, mash the pedal and take note of where the tach is at when the car takes off.

wouldn't be that the "flash stall" ?

[Nacho-RT74]

Another silly question from a novice.  What exactally is torque converter stall?   Is it as basic as it sounds?  I don't know how it relates to a build...

stall speed is the RPMs where the tranny engages completelly without slippage ( or minimun slippage allowed as converter specs or built ) with engine through the torque converter.

Stall speed doesn't mean car will begin to move at that speed, is just the "full" engage.

Is like on a manual tranny, the clutch engages tranny and engine without stop or "stall" the engine. To make that  you press gas pedal and release slowly the clutch pedal untill engine is able to move the car without "stall".

so the torque converter is the clutch on an auto tranny, but through hidraulic coupling

[FLG]

Nacho i remember talking to you at carlisle...dont worry your not going to break anything give it a shot.   

[grdprx]

Right on, thanks Nacho.   Sorry for jacking your thread.   

[Nacho-RT74]

No prob... maybe somebody will be able to chime in with a better and accurate explanation... I just posted what is my understanding on the stall and related stuff

anyway my question is still on the air.

[firefighter3931]

To properly check flash stall you need to put the transmission into 3rd gear at 10 mph and mash the throttle. Look at the tach and see where it engages and you'll have your stall speed.

* converter stall speed is directly correlated to engine torque....the more torque, the higher the stall speed. A 440 will stall higher than a 383 using the same converter.



Ron

[Nacho-RT74]

yeah but I was wondering about the regular stall itself not the flash stall. I was thinking that use the regular method was more less the same that going down on a mid/hard slope hill and holding the car with tranny on 1st gear will give me the stall.

I got around 1800-1900 RPMs in that way.

( I don't feel safe making the regular method )

[John_Kunkel]

Any way of measuring stall speed that doesn't involve WOT isn't going to be accurate, the amount of rpm needed to hold a car immobile on a steep incline will be more related to the angle of incline, car's weight, gear ratio, etc.

[Nacho-RT74]

Any way of measuring stall speed that doesn't involve WOT isn't going to be accurate, the amount of rpm needed to hold a car immobile on a steep incline will be more related to the angle of incline, car's weight, gear ratio, etc.

oh ok sounds logical

[firefighter3931]

Any way of measuring stall speed that doesn't involve WOT isn't going to be accurate, the amount of rpm needed to hold a car immobile on a steep incline will be more related to the angle of incline, car's weight, gear ratio, etc.

I think i mentioned this a few posts up....Natcho, are you paying attention. 



Ron

[Nacho-RT74]

yeah I'm paying attention LOL... but didn't get that on your post.

damn I don't feel comfortably making teh regular test... I feel like I will break something

[John_Kunkel]

The 3rd gear mash test is only reliable with a manual VB, if the trans is quick to react it will kickdown before the tach stabilizes at the flash stall speed.

[Musicman]

I just start from a dead stop on a level grade... put it in gear, mash the pedal and take note of where the tach is at when the car takes off.

I forgot to mention... if the tires spin the test is invalid, the numbers will be high, the tires need to stick. Everything needs to be up to temperature as well... and Yes your right, this is a test for Flash, but it's close enough in my book.

[firefighter3931]

The 3rd gear mash test is only reliable with a manual VB, if the trans is quick to react it will kickdown before the tach stabilizes at the flash stall speed.

True John 

You could allways disable the kickdown linkage to perform the flash stall test. 



Ron

[Nacho-RT74]

You could allways disable the kickdown linkage to perform the flash stall test. 

I was scrolling down and thought on that before read your post at the end, so you stolen my words

[John_Kunkel]

With the KD linkage disconnected the clutches might slip due to reduced line pressure.  It's always something.