200 4r Clearity

[calwldlife]

Hi
Read alot here :smile:

If I understand the info
GN version have bigger intermediate servo/cover
valve body bigger holes/more holes
govenor weights lighter to spin more rpm for shift points.

Now
I have an OG 200 4r.
Bought TCI Pro Super Kit with Trans scat valve kit
GN inner servo (GM)
intermidiate servo cover BowTie (after market)
The big TV boost valve
10 vane pump

I see alot of ads selling GN and Monte valve bodies.
I also see GN govenors.

So whats the deal, isn't the valve body the same execpt for the
plate?
Does the govenor only supply wide open shift rpms?
Is there any other differences in the intermidiate servo
besides the inner servo and the cover?

Will my OG be a GNational after the rebuild?

The trans scat shift kit has 2 choices:
race and towing. Any opinions on which is better for tranny life
comfort of driving, ease of TV set up?
Help me help myself

Thanks
Rick

 

[mikestertwo]

The difference is mainly the calibration of the valvebody, the spacer plate, the governor, and the intermediate servo. The governor controls shift points at all speeds along with the adjustment of the TV cable. Will you have a GN trans after the rebuild, NO! The shift points vs. throttle position will be different. Will it be as strong, of course. The internal rotating parts are the same. Is this trans going in a GN/turbo car?

 

[Firechicken]

As Mike says, the valvebody, governor and servo are the pieces which make the GN's 2004r different from the rest.

I highly recommend buying CK's rebuild guide. It is hands down the best one out there and if you follow his procedures you will have a great tranny.

 

[bison]

You need to start with a high performance vb and the governor that came with the high perf vb. An OG is unacceptable for a performance application. There are many internal differences with the valves and springs as well as the hole sizing and throttle valve diameter. Shift timing and quality will be sub-par with the OG and it will not be easy to make it function like a high perf with the valves and springs it has in it. Chris at CK could set you up with a BRF vb and recalibration kit fairly cheap.

 

[calwldlife]

Thanks for responding.
I am putting this trans behind a 396 bb cheby.
no crazy HP or rpms.
350-400 hp , 5000 rpms

I understand (I think ) that the VB, Gov, Servo are different
in the GN.
My confusion is, Why is the VB, Gov so sought after.
Is it the shift rpms?, Is 6000rpm's the reason?
I want a tranny to shift in the low 5k rpm's.

How would a GN VB, gov bennefit me?
I know enough to be dangerous

Also the axle ratio will be @ 3 to 1, so wouldn't an OG
be correct?

I understand engines, would the VB be say the cam in a motor?
Would the Gov be the rev limiter?

I want what every body wants:
good performance with dependability.

I ain't to old to learn.....................
Rick

 

[bison]

Thanks for responding.
I am putting this trans behind a 396 bb cheby.
no crazy HP or rpms.
350-400 hp , 5000 rpms

I understand (I think ) that the VB, Gov, Servo are different
in the GN.
My confusion is, Why is the VB, Gov so sought after.
Is it the shift rpms?, Is 6000rpm's the reason?
I want a tranny to shift in the low 5k rpm's.

How would a GN VB, gov bennefit me?
I know enough to be dangerous

Also the axle ratio will be @ 3 to 1, so wouldn't an OG
be correct?

I understand engines, would the VB be say the cam in a motor?
Would the Gov be the rev limiter?

I want what every body wants:
good performance with dependability.

I ain't to old to learn.....................
Rick

There are too many reasons to list as to why the valving and calibration of the OG make it a bad choice for high performance. Changing any one part of the system will make more problems elsewhere. If you want good shifting at 5000 rpm go with a BRF. If you want it to shift a little later (5500rpm) at WOT go with a CZ or KZ. Use the corresponding governors and seperator plates that came with the vb's. You will need to change the nylon gear that is on the governor and the driven gear or your speedo will be incorrect.

 

[77 cruiser]

But it can be done if you are willing to pull the pan several times, play with the gov. & also drop the VB a few times to do some tweaks.

 

[bison]

But it can be done if you are willing to pull the pan several times, play with the gov. & also drop the VB a few times to do some tweaks.

I personally dont know anyone that successfully made a non high performance vb work like a high performance one without swapping all the springs and valves out. You are altering the valving and governor circuit at the same time which will cause all kinds of shifting problems at all throttle angles. A hodge podge of vb components thrown together will cause more problems than its worth. Its much cheaper and easier to start off with the correct parts for the job and alter the calibration a little form there.

 

[calwldlife]

OK,
I found some VB pics and see the valves and springs.
Yes changing all of them, without knowing to what or which
is problematic.

Is it the timing of the load/unload of band/clutch that the GFR
VB does that make it better?

Is it the apply pressures?

What does the gfr do so much better that I should seek one out?

Thanks for your opinions and knowledge

I am close to understanding, help me get there

 

[mikestertwo]

There are too many reasons to list as to why the valving and calibration of the OG make it a bad choice for high performance.

As bison said, there are a lot of reasons. Valve diameters, spring rates and tensions, governor curves, spacer plate hole diameters and position, etc. all contribute to how the transmission shifts. Trying to make a non high performance valve body react like a performance one is very difficult. You will probably have to change just about every valve and spring in the valve body to make it perform correctly. Your better off just starting off with a valve body intended for performance use like a BRF, OZ, or CZ with the matching governor and spacer plate.

 

[Ttype6]

OK,What does the bfr do so much better that I should seek one out?

Hey,how about an answer to your question? The BRF valve body has one thing diferent from all other 200-4r valve bodies.The difference is the diameter of the 2-3 shift valve. Since it rides in a bore drilled into the valve body casting you would have to bore that hole in your valve body to a larger diameter. The reason the valve is bigger in the BRF is because the factory determined that the 200-4r installed behind the turbo V6 motor would shift into 3rd gear at too high an rpm,or not at all with the smaller valve in you valve body.Everythig else important can be changed because other valves of different size ride inside coresponding bushings that easily slide in and out of there bores. Since you aren't using the turbo V6 motor,this isn't an issue to you,so you don't need a BRF valve body. You should,however,start out with the Montecarlo SS valve body because It's already what you need,as it already shifts at 5,500 rpm with the appropriate governor.You don't want to shift your 396 at 5,000 rpm.because it makes maximum power at 5,500. There is,however,no reason why you shouldn't try what you have first to see how it shifts. It will shift too early,but you can fix that by manually shifting it. If you like the shift quality,buy a monty SS governor to get closer to the shift rpm. you desire.