Overdrive Options
So, let me get this straight, the a500/a518/42rh/46rh are driving the OD all the time even though not in OD therefore pulling HP, yes? I just don't see it. Why would Mopar build a trans meant to help improve mpg yet rob as much as 100hp? That would mean it wouldn't be good for mileage over a normal 904/727 even with the OD! I would really like to hear from a Mopar trans tech on how the OD trans works to see if this is actually what is happening.
Yes the OD is being driven all the time.... Whether it is engaged or not.
It is an add on to the rear of a 904 or 727 (500/518 respectively). It is NOT a 4th gear inside the main case of the transmission. You ask "why would MOPAR build a trans...?". Because while it is very true that the acceleration would be greatly affected, once it is spun up to highway speed.... Now your parasitic drag has been neutralized, or at least minimized. So the .69 will still give you a better cruise performance and mileage.
I hope a trans tech speaks up here, but I can tell you what the difference feels like and it is dramatic!!!!
Look, I don't want to bash anyone's hopes, dreams, and expectations.....
However, I would like people to know, and not be disappointed when their project doesn't work the way they expect it to. This OD from MOPAR I think was an initial attempt at getting better gas mileage.... They have come up with better technology since then.
While my car with the 518 impressed everyone that I ever took for a ride, it is now unbelievable!!! The horsepower that has been freed up, makes this car run amazing..... First and second gear are like being on ice....
I wanted to retain the OD, AND DIDN'T WANT TO BELIVE THAT WAS THE PROBLEM!!!! Now I have a new problem..... I gotta buy some sticky tires!!!
Now that's a good problem to have, if you ask me!!! Todd
