ky

what does a stall converter do? i want to get my c4 rebuilt but im worried when i call the tranny shop theyll ask me questions i dont know the answer to. and i dont want to look stupid cause hes my boss's friend. and im hoping to get the hookups on a rebuild. does my tranny have a stall converter or do i need one?

jc92073

Every torque converter has a stall speed, some are low some are high. Most of the aftermarket racing ones are high. Basically you can raise the engine RPM without loading up the engine, great for racing if you want to run the rpm up and let of the brake.
If you hold your foot on the brake in gear and raise the rpm as high as it will go, that is your stall speed.

ky

oh ok. then i want mine low. cause its a DD 280-300hp cruiser.

so then, that means i must have a higher stall converter on my converter right now cause i tried to do brake stands but the engine would just rev up without breakin the tires free. or its just that my engine was completely crapped out and old and super tired and didnt have enough power to do it lol.

jc92073

The condition of the engine and tranmission could confuse the matter. Most stock t-c have less then 1700 stall speed. If you tranmission is slipping, it might notshow the true stall speed of the converter. Also, the converter might say 1900 rpm stall, but if you have a 200 hp engine and a 500 hp engine the stall speed will not be the same, the 500 hp engine will be able to get to a high rpm because the of the extra power.

You might want to go with a 1900-2100 stall converter, will drive well, plus you can have a little fun once in a while.

falconfixer

You can't use the 'power brake burn out test' to determine the correct stall converter. You may not have enough hp to overcome the brakes...

Sounds (to me) like you want to stay STOCK for the stall converter.

ky

yeah im staying stock for the converter. i just had to figure out what cam i am going with first.

67mustang302

Higher stalls can also lead to main thrust bearing wear in the engine if you drive it at low rpm a lot, since the converter is moving fluid and pushing the housing towards the engine, causing the crank to ride the thrust bearing. A lockup converter running at/above the stall speed locks up,preventing that from happening. That's why it's reccomended to not drive with o/d on in the city in automatic cars. So converter speed for a street driven car is also a matter of what rpm you cruise at. Bigger cam/intake/head combos want higher stall speeds, otherwise the car is a dog off the line since the converter isn't slipping at a high enough rpm to make decent power.

jc92073

This link goes into more detail about stall speed. Geared towards racing though.....

http://nhra.com/dragster/1999/issue0...echnology.html