n xntrx volvo said:
philip- i'd love to open that valve body open to see what was done and find a way to replicate it for other people. i hear the nose of the conv is weak, but have yet to see proof. the higher stall of the 72 guts should be sufficiant. i'd worry about going any higher on stall due to heat. that said, if i could dig it up, i'd be on it, if just for the learning experience. any pictures of the improved rear bush? also, shouldn't a 93 be a aw71L?
I don't have any pictures of the improved tailshaft bushing location, but I have seen it because I have removed the tailshaft cone in both my 89 AW71 and my 93 AW71. The bushing is moved out to the end of the cone instead of at the beginning of the cone relative to the trans body. This may allow the cone to provide more structural support for the shaft. The mechanics I use say they have not replaced nearly as many bushings on the later trans. I think this change occurred around 92 or 93, but was short lived because the AW71 was used only on the 940 Turbo at that point and that model was discontinued in the US a couple of years later.
The converters are definitely very different for the lock up and non lockup trans. You will have to decide which way to go. Theoretically a lockup is weaker, but some domestic ones have held decent power stock and been modified for more. I think the Buick GN is one example.
I think you could go higher stall than the MVP if you used synthetic fluid and a large heat exchanger -- possibly one with an electric fan. People measure stall differently, but the best method is the zero boost method. Run the engine up to 0 vaccum and 0 boost while holding the brake until, if applicable, the wheels spin. That will be the true stall. The same converter can yield different stall speeds on different motors, depending on the torque the motor produces.
On the AW71, the governor inside the tail shaft housing does not control shift point rpm. I don't know why, but when I was at Level 10, they added 5 ounces with no effect. The change was internal to the valve body. They said something about the rpm shift point at full throttle being controlled by the "ramp." Again, I don't know what that means.
If I can get the trans out of my car and sell it in the next couple of months and it ends up out west, maybe you can get pictures or have a look.
Philip Bradley