Is there someplace that tells how much weight to take off to raise shift points a specific amount or percentage? A curve?

Thoughts? Sources?

CJ

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Part of Tyrde-Browne Racing

I am at the same spot. Several years ago i made a new govenor for my 63 Max wedgecable shift 727. it shift about 5800. It is so long ago i cant remember what i did. There used to be a picture of the one I made on the 1962 to 1965 mopar website bit i was just there and cant find it. I may have to sit down and redesign it again. I wish I could find the picture . it would rmind me of how I made it. WHatever I do it has to be done today because I want the trans back in the dragster for the weekend.
Don

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Don

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Joshua

Thanks Don and Josh!

It would be interesting to get the spring rates and weights figured out and posted up here!

CJ

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Part of Tyrde-Browne Racing

Do both shift points happen at the same RPM but to low or high... and throttle pressure adjustment does not get the right RPM?

Or... do the shift points happen at different RPMs?

Usually, I have the second problem, and adjust shift valve springs first, to get the shift points at the same RPM... then work on throttle pressure or govenor pressure, if I need to move both shifts up the RPM range.
DD

Both occur at pretty close to OEM on my tranny. 4000ish. I have the Lokar adjusted for max rotation of the TV lever at WOT.
I have a shim kit for the TV spring, along with a new TV and Kickdown valve and bushing.

The instructions relate to MPH rather than RPM on the shims. 1 shim results in .5psi increase on the Kickdown and 7psi to the TV line pressure increase with the OEM spring used. This is supposed to increase the shift point 3-5 mph. Two shims increase pressure to 14psi. Three shims are not recommended with the OEM spring.

Going with the governor allows me to set my shift points based on rpm. This, however, is contingent on the governor speed selection matching to spring rates in the 1-2, 2-3 and TV rates being correct for the application.

I am wondering how accurate these governors will be when installed in different transmissions. Since my car is shifting right at the OEM spec, I take it that the 5000 rpm governor will shift at 5000 rpm at both transitions, breakaway to second, and second to third.

I guess I can be a guinee pig and give it a try. If it's still too low, I can bump up to the 5200 rpm governor, and decrease the adjustment slightly to the TV with my Lokar cable.

Eh?

CJ

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Part of Tyrde-Browne Racing

http://www.sonnax.com/part_finder.php?m ... w_only_sc=

Some interesting stuff...

CJ

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Part of Tyrde-Browne Racing

What's RPM is the stock governor rated for?

Say it's 4000.....

If you get a 5000 rpm governor, and your shift points were 3000 (1-2), and 4000(2-3). I'd think the 5000 governor would change it to 3750 and 5000.

If you played with the shift springs before getting the governor, and got them both to 4500, then tried a 5000 governor. I'd think your shift points would go to 5625 each.............(5000/4000)*(existing shift rpm)

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

How thick are the shift shims?


If you take some measurements, you can take the quess work out of adding shims to the springs..........

You need to measure the following:
1. Free spring length
2. Spring rate
3. Installed length
4. Length of spring when shift occurs (when to piston uncovers the port in the valve body)

Say you get the following:
1. 2" free length
2. 10lbs/in rate
3. Installed length 1.5"
4. Length of spring when shift occurs 1"

So the spring has been compressed 1" with (10lb/in * 1in)= 10lbs of force.

Say this happened at 4000 rpm and you want 5000 rpm.....

So you'd want it to take 5000/4000 * 10lb = 12.5lbs of force to open up the shift port.

12.5lbs / (10lbs/in) = 1.25" of spring compression needed

1.25"(wanted) - 1"(have) = .25" more preload.

You need a .25" shim..........

Or you can play with different spring rates.......... (you figure it out.. )

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

http://www.1962to1965mopar.ornocar.com/ ... 3tech.html

Here is the pic of the one I made. I made it from a picture of the old MP weight kit. It works but I dont remember the weight it was so long ago. All i can tell you is it works well enough I have never wanted to change it and rarely if ever now use the push buttons. Something in the far recesss of my mind is telling me the wieght had to be heavier rather than lighter to raise the shift point. More centrifical force kept it in longer until presssure could finally overcome it but I may be dreaming . I made it probably about 1999 so the memory is far from fresh. There is also the dual pickup filter spacer that someone was talking about in a nearby thread. Anyway i have to figure this out again as I like the auto shift feature on my dragster.
Don

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Don

From the photos it looks like you were playing with the inner weight. Is that correct?

The spring rates I was playing with were in the valve body just for clarification. I went ahead and dropped the valve body and installed two shims on my Throttle Valve to increase the OEM spring tension.

I don't have what is needed to check spring rate here, but should build a tool for such work. Wouldn't take much.

I'll measure the extra shim and post the size. The OD of the shaft it fits on is .255" I measured the new valve and my valve to make sure they were the same. Since the valve was working to OEM spec with OEM adjustments, I just reused my existing parts.

Since both shifts are pretty close to the same engine speed, hopefully this will get me in the ball park with my shifts at the strip. I'll let everybody know how the kit does. It allows for various adjustments to shift points. Lower and higher.
It's a Sonnax kit, part number 22771-HDK3. By the time I paid shipping it was $53.19 I didn't want to spend that much. Oh well. I'll get the dimensions on the shims, and will be able to play some games with the numbers for other adjustments on my many projects!

CJ

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Part of Tyrde-Browne Racing

It is beginning to come back to me now. I am working on it today . I should have it sorted out sometime next week and will give a full report.
I believe if memory serves me correct it was the inner weight and making the large section thicker increased the spring pressure and gave the higher shift points. I wish I had made notes now.
Don

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Don

I use a manual valve body and don't worry about it. It shifts when I move the lever.

Use an RPM activated air shifter for you drag race only guys.

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11.02 @ 120.56
http://www.youtube.com/watch?v=EAxRmoDgsdY
Chassis dyno
http://www.youtube.com/watch?v=wd6hFGzLJMc

Not an option for me. I had two friends with the bottle system. One forgot hook up his trigger wire so it worked on a default mode shifting at according to his telltale tach somewhere between 8000 and 9000 RPM. Not a good thing in a 540 inch engine. The other ran out of CO@ on his liscensing run and drove the whole quarter mile in with only the 1-2 shift. That motor will not be able to do it again since it was a 3 speed. 141mph in second gear is hard on a motor. I now these are two extreme examples and neither had bothered to chip their rev limiter either but it is much easier to install a govenor kit then to install the air shifter . The cost is only 70 to 80 bucks even if you bought it and you never have to worry once it is done. It is permanent. I am looking into now that the internals of a 904 and a 727 governor are the same. If that is so then the kits be they sonnex or whatever for the 727 will work in the slant 6 904 trans as well.
I have however remembered despite my grey hair how i did it and will tend to mine Monday after my day of rest.
My MAX WEDGE car works perefectly everytime at 5850 WOT (since 2000)but drives normal otherwise. I want the same for my rail. I am too old and stiff to move the shifter in the dragster and besides if truth be known I am afraid to take my hand off of the hand brake during a pass.

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Don

Well, the sonnax kit didn't do much!

With shipping the governor is going to run $85.

Good grief. Sure be nice to know it will work. The 5000 rpm governor should do the trick if so.

That mod was a lot of work for 200 rpm!

CJ