whats the difference between the two and which is the best for a daily driver??

 

Your 4th gen has a lockup converter, and unless you are optimizing a car for the strip or have a very high-po setup that's what you should get. A lockup converter has the ability to "lock up", which is to say mechanically couple the impeller and the turbine such that there is no "slip" between them. In a 94+ 4th gen the lockup clutch is controled electronically and is activated in 4th gear when certain conditions are met. Basically, when the car is not accelerating for a few seconds (IOW, cruising at a steady speed) it will lock up. It stays locked until a programmed rate of TPS increase relative to speed is exceeded. You can observe this as you drive by paying attention to the tach, engine sound, and how fast the car accelerates relative to throttle position. When the converter unlocks, the engine speeds up a few hundred rpm and the rate of acceleration increases. Conversely, you can see/feel the rpms drop when it locks up.

The lockup feature saves fuel and engine wear by decreasing rpm. Race converters are non-lockup primarily because the sanctioning bodies don't allow them. Consequently, no one makes the lockup parts strong enough to stand up to WOT engagement with a powerful motor. Before they were disallowed from serious competition people did experiment with them and gained 3-5mph through the traps by locking up. There are some lockup converters that are advertised as being up to racing, but I wonder exactly what the hp capacity of these is.

Rich Krause