OD pressure switch > 518

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draginmopars

draginmopars

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I have a 45psi switch in my 518
to make trans shift into over drive at 45

It shift at 39 mph
I figured out it is due to gear ratio and tire size

Does anyone know where I can find the math to figure what switch to use>

I'm changing gear to 4.56 and a 315 x 60- 15 tires
converter Now, stalls at 3000

I'll have the car running again soon

thinking to drive it at 3500 rpm in drive
see what the Gps mph is , buy a switch for that speed

suppose to be 1 psi =1 mph

Thanks
 
Woods74 said:
I got the math for ya: +1 toggle switch = 0 headaches. Done deal..
Click to expand...

I all ready have 2 toggle switches
1 for LU > on / off

1 three way, that I want to
use a pressure switch for cruising > shift around 3500 in drive
another pressure switch to shift at 6300 in drive > Race Mode

I would get a headache, trying to remember to turn the OD on at exactly the same time,
Every time while racing

004_zpsxf4a74cq.jpg
 
I think the trans pressure is already going to be maxed out way before 6300 requiring a different way to make it automatic.

They do have the vacuum switch for activating the solenoid to command the shift but I think you would have the same problem with it as the vacuum is going to be way low a long time before you want it to shift, and you sure don't want to be lifting your foot in a race to get it to shift.:D
 
TrailBeast said:
I think the trans pressure is already going to be maxed out way before 6300 requiring a different way to make it automatic.

They do have the vacuum switch for activating the solenoid to command the shift but I think you would have the same problem with it as the vacuum is going to be way low a long time before you want it to shift, and you sure don't want to be lifting your foot in a race to get it to shift.:D
Click to expand...

yes, the other switch I found is a 52 psi
I have thought to use the (45 psi) wired into a RPM switch.
So that it could only shift into OD, while in 3 rd

play with the governor weights, to keep the rpm's below that point in 1st and 2nd.> WOT
???????
what do you think
 
draginmopars said:
yes, the other switch I found is a 52 psi
I have thought to use the (45 psi) wired into a RPM switch.
So that it could only shift into OD, while in 3 rd

play with the governor weights, to keep the rpm's below that point in 1st and 2nd.> WOT
???????
what do you think
Click to expand...

I'll have to think about that for awhile, because the governor is going to make that happen in the later gears also I think.

It seems to me if you are only really concerned about racing and can cross the line in third coming up on your max RPM's it would be better.
That way the governor could be played with to delay the shifts you need for racing and 4 & OD can stay off completely.
Is that doable with different tires or gears?

That way you could just leave 4th and OD for street only.

Just thinking.
 
Well, I am totally unqualified to answer this as I have my 518 rebuilt and not installed but...

I bought an adjustable NOS switch from Summit. Allen key adjustable so I would be able to customize when it engages. I think it was a 3060 psi switch or something similar.
 
1973Barracuda said:
Well, I am totally unqualified to answer this as I have my 518 rebuilt and not installed but...

I bought an adjustable NOS switch from Summit. Allen key adjustable so I would be able to customize when it engages. I think it was a 3060 psi switch or something similar.
Click to expand...

That number doesn't make any sense to me because there ia nothing in the car that ever comes even close to that pressure. (well, maybe when a cylinder fires)

The OP has the switch, but it currently has to be manually operated to shift when he wans it to.
I don't think the adjustable vacuum switch (this is what I think you are talking about) would do him any good at those throttle openings and RPM's.

So far I can't think of a good possible solution to control it a WOT when he wants the shift except something that does it using MPH like a cruise control senses speed.
 
Typo.

30-60 psi

I think that was the pressure. Would have to look it up to verify.
 
Not a vacuum switch, pressure.

The switch he has, if I am reading this right, is based on his transmission creating a certain pressure. If it doesn't, his mph is off from what is advertised.

If you call, PATC, whos sells a kit for this, they want to know what pressure your transmission has where the switch goes.
 
1973Barracuda said:
Not a vacuum switch, pressure.

The switch he has, if I am reading this right, is based on his transmission creating a certain pressure. If it doesn't, his mph is off from what is advertised.

If you call, PATC, whos sells a kit for this, they want to know what pressure your transmission has where the switch goes.
Click to expand...

hey at least your making us think. :D
 
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