Torque Convertors: I know nothing about them. I do not understand what "stall speed" is, "lock up", or any of that. In what instance would I need a torque convertor with a 2500 stall speed? I know the number is RPM, but other than that...I am a complete torque convertor idiot. Can someone take the time to type me an explanation, or refer me to a link so I can teach myself? ou:
Try these. http://auto.howstuffworks.com/torque-converter.htm http://www.tciauto.com/tech_info/torque_converters_explained.htm http://www.carcarecouncil.org/Auto_Transmission/torque_converter.shtml
Thanks Larry! I read through all thjat stuff, whjich cleared up a LOT. But what I still don't understand is...if a convertor has for example a "2500 stall speed" does that mean the car will not launch until 2500 rpm ? That cant be right can it ?
No not at all. When a torque converter is below stall speed, it multiplies torque. The engine half of the converter can turn quicker than the output to the transmission. This multiplies torque. Think of a 10 speed bicycle. In 1st gear, you pedaling really fast, but the wheels move slower, and you develop more torque to get you up a steep hill. The gearing gives you greater mechanical advantage. The speed of the 2 halves of the converter catch up to one another at stall speed, and torque is transmitted one to one, not multiplied. A 2500 stall converter will allow an engine to flash up to 2500 RPM or more as the throttle is opened suddenly from a dead stop. This is important when you have a cammed engine. The bigger the cam, the more the power range of the engine is bumped up the RPM scale. If your cam comes on at 2500, but the converter restricts the RPM's from a dead stop, the car will accelerate very poorly from a stop. The downsides to higher stall converters is that they slip more than is necessary once the car is moving, and they make more heat, which kills gas mileage/efficiency. But they enable the car to leave the line "on the cam" A car will move with a 2500 converter well before 2500 RPM.
ok I follow you now. So if a cam made peak power between say 2000 and 5500 rpm a 2500 rpm stall convertor would probably be a good choice then right? Even with running a 3.73 rear axle ratio ?
Know what Larry? You are cool Mofo. I see you sharing info all the time on these boards, and you just helped me understand something major in a relatively short time. I completely get the concept now. Thank you for your help, patience, and knowledge. :TU:
