autopar3000
Well-Known Member
Here's my 2 pence on this. Get ready, this is going to be a long post.
I have a 70 Dart with a 3.23 rear gear, and I'm running a 5.9 and 46rh from a 1994 B350 van with the factory EFI, and the PCM controlling OD and lockup. In 3rd gear with lockup engaged I'm at 2600 rpm, in OD with lockup about 1750.
First, some information on my setup: My TV cable is adjusted so the trans shifts from 1st to 2nd at around 5200 rpm at wot, so probably a bit higher than the B350 would have been set up from the factory. The trucks and vans probably would have been a 4400 - 4600 rpm wot shift into 2nd. The speed sensor on the transmission tells the PCM how fast the car is going and the speed it shows on my speedometer is dead on accurate, so the PCM is getting good data. I have a 2500 stall torque converter, so a bit more loose than stock.
When I am accelerating normally, the car will shift into OD almost right after shifting into 3rd. Then lockup will happen shortly thereafter. Keep in mind my transmission probably holds 2nd gear longer than the PCM is expecting, so by the time the trans gets to 3rd the PCM is ready for OD. On slow acceleration it'll go into 3rd at about 54 km/h and OD at like 60 km/h, and LU at around 65. If I can get the power steering fixed this weekend I'll record a video showing the tach so you can see this is action.
Interestingly, if I'm driving in a more "spirited" way, the PCM seems to recognize this and even if I accelerate normally after a hard acceleration it will seem to shift into OD and LU a bit later.
The trucks my setup came with could have been up to 5500 lbs. Obviously way more than my 3200 lbs Dart. The PCM is willing to let me drive around at 1200 rpm in OD thinking the vehicle is over 5000 lbs, probably because the Magnum engines made great torque and the engineers were tuning for fuel economy. So ultimately I don't think you will have any issues if you shift into OD super early, as long as your engine makes enough torque at that rpm to move the car. And of course the earlier you get into LU the less heat will be generated in your trans, since there isn't the shearing of the trans fuild in the converter.
I have a 70 Dart with a 3.23 rear gear, and I'm running a 5.9 and 46rh from a 1994 B350 van with the factory EFI, and the PCM controlling OD and lockup. In 3rd gear with lockup engaged I'm at 2600 rpm, in OD with lockup about 1750.
First, some information on my setup: My TV cable is adjusted so the trans shifts from 1st to 2nd at around 5200 rpm at wot, so probably a bit higher than the B350 would have been set up from the factory. The trucks and vans probably would have been a 4400 - 4600 rpm wot shift into 2nd. The speed sensor on the transmission tells the PCM how fast the car is going and the speed it shows on my speedometer is dead on accurate, so the PCM is getting good data. I have a 2500 stall torque converter, so a bit more loose than stock.
When I am accelerating normally, the car will shift into OD almost right after shifting into 3rd. Then lockup will happen shortly thereafter. Keep in mind my transmission probably holds 2nd gear longer than the PCM is expecting, so by the time the trans gets to 3rd the PCM is ready for OD. On slow acceleration it'll go into 3rd at about 54 km/h and OD at like 60 km/h, and LU at around 65. If I can get the power steering fixed this weekend I'll record a video showing the tach so you can see this is action.
Interestingly, if I'm driving in a more "spirited" way, the PCM seems to recognize this and even if I accelerate normally after a hard acceleration it will seem to shift into OD and LU a bit later.
The trucks my setup came with could have been up to 5500 lbs. Obviously way more than my 3200 lbs Dart. The PCM is willing to let me drive around at 1200 rpm in OD thinking the vehicle is over 5000 lbs, probably because the Magnum engines made great torque and the engineers were tuning for fuel economy. So ultimately I don't think you will have any issues if you shift into OD super early, as long as your engine makes enough torque at that rpm to move the car. And of course the earlier you get into LU the less heat will be generated in your trans, since there isn't the shearing of the trans fuild in the converter.
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