Automatic- O/D on or off

[axax]

I can't decide what's faster and won't be going to the track any time soon.

Any ideas? I feel like O/D off is slower but with higher engine speed, so it just makes a lot of noise and barely takes off...

[M1L1T1A]

over drive OFF for sure man, only time you need to put it back on is if you are running out of gear... but you should be good till 90 or so.

[5.9 R/T]

^^^What he said!
On the long run you'll need O/D, but for something like a drag race you difenitly don't want the O/D on.

Just to give you an idea, here are the time I ran at the track earlier this year without O/D...
14.12
14.17
14.24
14.25
14.27

Than I let it on for one run....
14.46

So it gives you an idea

[irnwkrkev]

It might be a little different with the 545rfe. I think if you put the OD off it locks up the converter sooner. I was making some runs with the dynolicious app on my iPhone and when I had OD off I felt the converter in 3rd lock up and the truck slowed. I would imagine you shouldn't see 4th in the quater unless you've got low gears and are running pretty quick.

[moparsz]

leave o/d off, you'll be a little faster. and you'll see 4th in the 1/4 even if you run in the 16's

[03DakStampede]

When I was stock it didn't matter one way or the other because i could run the 1/4 in 2 gears crossing the traps at 6k. With my current setup I need 3rd but if I run with od off it will lock the converter in third gear so most of the time I run it with od on so I don't get the converter lock and once I cross the traps and let off the pass the truck will shift into od. For me it doesn't seem to make a whole lot of difference but with the 4.7 and the lack of torque when the converter locks it does slow you down

[irnwkrkev]

^ That's exactly what I noticed with my durango.

[axax]

what I seem to notice with O/D off is that I hit the limiter in 2nd and it doesn't want to shift, I feel like I have more control over the truck and how it shifts by using the pedal with O/D on than off, I'll definitely try different ways of driving it once my truck is in proper condition.

I'm running 42RE trans with the 5.2, best time has been 15.9, O/D on

[ColoDak]

usually I'll launch with the OD off, then when it's about to shift to 3rd I'll turn it back on. Of course my settings are differnet because of the Superchips

[irnwkrkev]

I guess the trans locking in early in third with OD off is only an issue with the 45rfe/545rfe trans (4.7L). It helps when towing with the OD off. There's no way I could reach fouth gear in the quarter mile, especially with 3.55 gears.

[5.9 R/T]

Originally Posted by irnwkrkev

I guess the trans locking in early in third with OD off is only an issue with the 45rfe/545rfe trans (4.7L). It helps when towing with the OD off. There's no way I could reach fouth gear in the quarter mile, especially with 3.55 gears.

Probably, but if you run the 4.56 you will want the o/d off for sure cuz it will try to shift in 4th. IIRC the 3.92 gears did the same...

[Mikes99Dakota]

O/D off made NO difference with my truck even if I kept it on. Some people say differently.

[Dakota RTNX]

i used to run O/D off while racing but then after i got a shift kit and SCT tuner it started shifting too early. now i run with O/D on and it shifts perfect in every gear.

[99Dakota]

O/D off makes no difference to me until like after 70. if i back off quick and let it lock up it pulls faster. wide open without feathering its still faster for me because it bings the rpms back down into the power at lock around 85 and i will pull it to about 100 and turn it back on

[axax]

my tranny has been acting weird recently, I've found since I got my truck back that O/D off is faster until of course I run out of gears