I ran one of the switch-pitch converters in the turbo 400 for years when I was racing. I used a manual switch hooked to the shift lever. Used to launch in the high side and switch as soon as my foot hit the floor. They were a little slow in switching so right before it would hit second gear the converter was almost locked up. The old car would run about two mph faster with the S-P than a stock 400 converter. GM had two different models, one was a little looser and wouldn't tighten up as much. I don't remeber what cars came with which one, but we tried both. Kept blowing the looser ones apart!
I have heard Dodge is working on a new model for some future truck. They are great for gas milage. The big advantage is you can run a low gear like 2.91 or so and still have power. That was the original idea from GM, they could get big heavy cars with low gears rolling easyer. Most I believe were switched by the acclerator peddle. I just finished some work on a 67 442 Olds that had one. It switched from the peddle linkage, about 3/4's throttle it would go into the loose side. Joe
