Im planning on getting a high stall converter 3200 to 3800, but I had a question about street use also.....

now my knowledge about stall converters is about this much... is that a stall converter doesnt engage untill the engine's rpm reachers 3200 (or 3800 if you go with a 3800 stall) ...

but not necesarily do I want the car launching at 3200 when im on the street. Can someone explain this to me better for using it for street purpose.

 

that's at full throttle. At a certain % throttle, it launches at a lower rpm.

 

So how excatly would u launch an A4 w/ 3800 stall at a drag strip? Idle then full throttle?

 

The best way to do it at the track is off idle. Unless you have ET Streets in which you can run the RPMS up at the line. You will not notice a ton of difference over stock in your day to day driving. I went from stock to a Percision Industries 3600 Vig. converter. It took me about a day to get used to the difference. It is kind of like having nitrous on your car. You can use it only when needed by putting your foot to the floor. If you drive away from a light like a normal person would. It just takes a little more gas to get it moving. More or less feels like it is slipping a little coming away from a light with little throttle. Put the pedal to the floor and off you go, totttttttttttttaaaaaaaaaaaaaallllllly different feel over stock.

All I can say is go to the 3800 stall if you are going to have drag radials on the car or ET Streets. If stock tires, I wouldn't go any hire than 3200-3400 stall.

Hope you enjoy the ride. Let me know what you think when you get it done.

Good Luck,

 

The stall speed of a torque converter does not mean that it will take that many RPM's to get the car moving. The rated stall speed of a converter can only be seen with a trans brake. Brake-stalling the converter will show a lower RPM than what the converter is rated for. A higher stall speed will allow the converter to flash higher and keep the engine further up in the powerband on shifts. With my 3.73:1 gears and 3,800 stall speed TCI converter, I drop to right at 5,200 RPM on the shifts. So, it's not just the harder hit off of the line that will help with a higher stall; it's also the higher shift extensions.

How tight or loose a converter will feel will depend on what gears you're running. A 3,500 stall with 2.73:1 gears will feel MUCH looser than if it is in a car with 3.73:1 gears. The steeper gear helps to get the car moving, so the converter does not have to do as much work to get the car rolling or maintain speed. Your part-throttle RPM's will be increased with a higher stall speed, but it won't be increased to the stall speed rating. For instance, with my 3800 stall and 3.73:1 gears, my RPM's will hover around 2,500 RPM under "normal" driving conditions. Once the converter locks up, the stall speed is irrelevant because the converter has locked up to the crankshaft.

Torque converters can become pretty in-depth fairly quick, but don't think that you'll be seeing the # of RPM's that the converter is rated for when driving around town. You will have an increase in RPM's, but it will depend on how high of a stall speed you go with. Feel free to give us a call or e-mail me at trevor@texas-speed.com if you have any other questions. I'll be glad to help you out.

Thanks!

Trevor
Texas Speed & Performance