TrailBeast
AKA Mopars4us on Youtube
Putting an A500 OD in my Dart and did a ton of research on how to make 4th(OD) and converter lockup work like I want them to.
The A500OD uses an electric solenoid to apply 4th(OD) and another to apply the torque converter clutch.
I tried to order a kit at about 85 bucks made just for this, but it had a couple of flaws in my opinion.
One is that the switches are at a set pressure, meaning you can order them to shift 4th at a certain speed and converter lockup at a certain speed after 4th.
The other was that nothing about them is adjustable (meaning their switching based on psi is set at the factory)
What if I wanted 4th a little later or earlier to better match 1,2 and 3rd gears and their respective rpm's? (Too bad, they can't be adjusted)
The same problem with converter lockup.
The kits come with an adjustable manifold vacuum switch to control when these two are allowed to engage depending on throttle opening amounts.
A little throttle and high vacuum would let the trans shift 4th and converter lockup earlier but only at the fixed settings in mph of the pressure switches, and a lot of throttle and low vacuum can keep them from engaging until later by stopping 12v power to the shift solenoids via the adjustable vac switch. (can be adjusted from 7 to 20 lbs of manifold vacuum)
Under hard acceleration OD and converter lockup will be blocked out until the manifold vacuum comes up again to the adjusted point on the vac switch.
That's nice and a must as far as I am concerned, but that wasn't good enough in my opinion because those two shifts are controlled by the switches on the governor port of the trans and would only engage at the non adjustable settings of the switches.
I decided I'm going to build a fully adjustable system by using 20-60lb adjustable switches for the 4th and converter lockup engagement.
This will allow me to adjust the 4th and/or lockup engagement to between 20 and 60mph separately from each other.
Switch pounds relates directly to mph, so If I set the switch for 4th at 45mph it will only shift from 3rd to 4th at 45mph at the soonest.
More throttle will delay that shift farther up in rpm's by the vac switch sensing a high engine load via engine vacuum and blocking the switch from engaging the solenoid to make the shift until that vacuum drops to the adjustable amount. (Basically just like the TP adjustment does on a standard 3 speed)
If I am in OD with the converter locked up and I step on the gas it will kick down to third until manifold vacuum comes back up from using less throttle.
Obviously I wouldn't want the 4th shift or converter lockup at 20lbs/mph but the switches I want to use are capable of it and can be individually set for between 20 and 60lbs/mph.
More likely I will have something like 4th at light cruise throttle come in at 40mph and converter lock engage at 50mph
This should keep it from hunting back and forth between 4th and lockup here where there are 45mph zones all over the place.
If I want the 1-2 shift at 20mph, the 2-3 at 35mph, the 3-4 at 40 and converter lock at 50 I can do it via the normal TP adustments for 1,2 and 3 and use the adjustable switches to adjust when OD and lockup come in.
If I wanted to delay the 3-4 shift another 5mph I will be able to do that by adjusting the pressure switch for 4th a little higher.
NONE of the kits allow this due to the non adjustable pressure switches they use.
The next step will be to put these switches in the cabin under the dash so these adjustment can be made on the fly.
This only requires that I route transmission governor pressure to the inside of the car where the hydraulic pressure can be converted to electrical switching and be adjusted.
I want knobs in a little compartment that say "OD+or-" for sooner or later and the same with Lockup.
Then a pressure and trans temp gauges would be nice to have also.
Sorry for the book, but in case someone is interested I have figured it all out and found the switches for just a little less than the 85 buck the kits have.
So THERE PATC!
The A500OD uses an electric solenoid to apply 4th(OD) and another to apply the torque converter clutch.
I tried to order a kit at about 85 bucks made just for this, but it had a couple of flaws in my opinion.
One is that the switches are at a set pressure, meaning you can order them to shift 4th at a certain speed and converter lockup at a certain speed after 4th.
The other was that nothing about them is adjustable (meaning their switching based on psi is set at the factory)
What if I wanted 4th a little later or earlier to better match 1,2 and 3rd gears and their respective rpm's? (Too bad, they can't be adjusted)
The same problem with converter lockup.
The kits come with an adjustable manifold vacuum switch to control when these two are allowed to engage depending on throttle opening amounts.
A little throttle and high vacuum would let the trans shift 4th and converter lockup earlier but only at the fixed settings in mph of the pressure switches, and a lot of throttle and low vacuum can keep them from engaging until later by stopping 12v power to the shift solenoids via the adjustable vac switch. (can be adjusted from 7 to 20 lbs of manifold vacuum)
Under hard acceleration OD and converter lockup will be blocked out until the manifold vacuum comes up again to the adjusted point on the vac switch.
That's nice and a must as far as I am concerned, but that wasn't good enough in my opinion because those two shifts are controlled by the switches on the governor port of the trans and would only engage at the non adjustable settings of the switches.
I decided I'm going to build a fully adjustable system by using 20-60lb adjustable switches for the 4th and converter lockup engagement.
This will allow me to adjust the 4th and/or lockup engagement to between 20 and 60mph separately from each other.
Switch pounds relates directly to mph, so If I set the switch for 4th at 45mph it will only shift from 3rd to 4th at 45mph at the soonest.
More throttle will delay that shift farther up in rpm's by the vac switch sensing a high engine load via engine vacuum and blocking the switch from engaging the solenoid to make the shift until that vacuum drops to the adjustable amount. (Basically just like the TP adjustment does on a standard 3 speed)
If I am in OD with the converter locked up and I step on the gas it will kick down to third until manifold vacuum comes back up from using less throttle.
Obviously I wouldn't want the 4th shift or converter lockup at 20lbs/mph but the switches I want to use are capable of it and can be individually set for between 20 and 60lbs/mph.
More likely I will have something like 4th at light cruise throttle come in at 40mph and converter lock engage at 50mph
This should keep it from hunting back and forth between 4th and lockup here where there are 45mph zones all over the place.
If I want the 1-2 shift at 20mph, the 2-3 at 35mph, the 3-4 at 40 and converter lock at 50 I can do it via the normal TP adustments for 1,2 and 3 and use the adjustable switches to adjust when OD and lockup come in.
If I wanted to delay the 3-4 shift another 5mph I will be able to do that by adjusting the pressure switch for 4th a little higher.
NONE of the kits allow this due to the non adjustable pressure switches they use.
The next step will be to put these switches in the cabin under the dash so these adjustment can be made on the fly.
This only requires that I route transmission governor pressure to the inside of the car where the hydraulic pressure can be converted to electrical switching and be adjusted.
I want knobs in a little compartment that say "OD+or-" for sooner or later and the same with Lockup.
Then a pressure and trans temp gauges would be nice to have also.
Sorry for the book, but in case someone is interested I have figured it all out and found the switches for just a little less than the 85 buck the kits have.
So THERE PATC!
Last edited:
