VP trans

Is there any way that you can find out both stall speeds in a VP converter with out having any numbers from it?

Thanks Basil

 

There is some useful info in this thread:
http://www.v8buick.com/showthread.php?t=143723

At least it tells you how to measure it properly.
Stall speed will also depend on how much power the engine is making. The same converter will stall higher on a 455 than it would on a V6.

The only way to know for sure it to try it.

 

you test stall speed with the car parked, brakes applied, and wheel chocks. i dont know if the swich pitch trannys are different but this is how you test a normal tranny. you have to mash the gas and the point where the car just begins to break traction is about the stall speed. it works better with a digital tach because they have a faster reaction time.
randy:beers2:

 

couple things i forgot are, only perform the test for a second or 2 because there is an extreme ammount of heat produced when you do this test. also, make sure you let the car run for a few minutes after the test to make sure the fluid has enough time to cool. it may be a good idea to drive the car a bit too.
randy:beers2:

 

Two different stall speeds are discussed here..

Larry's method is referring to "flash stall" which is the commonly used number to rate converters.


Randy is talking about Brake stall- in his description your really testing the brakes and tires more than the converter.. but it is a good way to get an idea.

To accurately test a converter can be done two ways.. In the first way, you have to have a very good race car chassis setup with a track with excellent traction.. and a tach recorder, so you can watch what the tach flashes to about a tenth of a second or 2 after the mash of the throttle- this tells you the effective stall with your combination and traction conditions.

The most accurate way is locked output shaft testing- this is done either on a trans dyno where the output shaft the the trans is mechanically locked to the stand, or most commonly done in drag race cars, by the use of a hydraulic transmission brake. You simply turn up your starting line rev limiter, and apply the transbrake, and nail the throttle.

As was mentioned, you only want to do this for a couple seconds.

Of course engine torque plays a big part in what a given converter will stall.

The more powerful the engine, the higher the stall speed, in a given converter.

JW

 

yes it all depends on how your brakes are. if they are weak then the test wont be accurate. correct me if im wrong but the piont of where the engine rpm wont go any higher is the stall speed. i cant remember exactly because i dont do stall speed tests enough to remember.
randy:beers2:

 

Sorry it took so long for me to jump back in here. It is not stock, I was more wondering if I could find a rough stall speed befor I put it in the car. I have flashed them and foot breaked them so I know how that all works.

Thanks for all the help.

It is for the 400 by the way

Thanks Basil

 

How should I measure it, Across or around the outside? Thanks Basil

 

I look at the converter and it is 13" and is a VP one. I was told that it was gone through and was no longer stock stall but I have no way of knowing. I noticed that it had 4400-VP on the front of the it, I dont know if thats the stall speed or if its anything at all.


Thanks Basil.

 

I thought you might say that. We are thinking about just getting a new one.
Thanks for all your help, Really.

Thanks Basil