Question for experienced 200r4 builders

fastblackracing

Well-Known Member
Joined
Apr 7, 2009
New engine combo will make usable power to to 7200-7500 rpm.

I have never had had one that I had to operate at over 6400.

Are there any special concerns doing this...pump cavitation, rotating members?
clutch pack centrifugally trying to apply itself?

Thanks for your input
 
Would like to know myself, I've been turning mine to 6850 -7000, Extreme Automatics stage 3

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I just bumped my shift points down. Haven't tested it yet but looking at 6500 or so

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Ive been wondering the same, the current combo for the LZ9 is capable of winding up over 7K, not like I will intentionally wind it up that far though.
 
New engine combo will make usable power to to 7200-7500 rpm.

I have never had had one that I had to operate at over 6400.

Are there any special concerns doing this...pump cavitation, rotating members?
clutch pack centrifugally trying to apply itself?

Thanks for your input
The GM 2004R uses what is known as a variable displacement pump, or what I like to refer to as a supply and demand system,which varies pump displacement based on the hydraulic systems operating requirements beyond the pump outlet. This is of course, beyond the influence of the pressure regulator valve in the system. Every revolution of the pump moves a certain volume of oil depending on the position of the slide. During upshifts, the oil volume demands of the oncoming friction element increase as that circuit is charged. When this is sensed by the oil pump, the slide responds by positioning itself in a manner that increases the amount of oil volume per revolution to satisfy the demands. This results in reductions in efficiency losses encountered when a fixed displacement oil pump and similar pressure regulation valve and spring system is in use. Although all unused oil is recirculated to the sump with both systems, less is moved under low demand operation due the ability to control volume or output per revolution within a variable displacement system. This is where the improvement in efficiency actually occurs. Now with that being stated, the higher the oil pump spins, the less time the system has to respond with increased volume by the re-positioning of the slide during a high rpm shift when the oncoming friction element is taking a "gulp" of output oil. If the pump slide springs are not matched to the projected operational rpm of the oil pump, the size of the boost valve diameter in use, oil filter and pick up and the list goes on the greater the pressure drop that will occur during high rpm upshifts ,and this is definitely a cause of concern due to the reduction in friction element capacity incurred as the pressure drop takes place. Also it causes the slide to bounce between its stops which occurs during changes in demand cycling of the slide and this often results in sudden slide fractures/failures. Properly calibrated springs keep pump volume high during desperate times reducing slide cycling, and allows the excess oil volume to be handled by the pressure regulators version of "return to sump" evacuation. All this means the slide goes nuts with stock parts beyond 5000 rpm. Install a pressure gage and see for yourself. There are huge difference with just nothing more than a filter change.
 
The GM 2004R uses what is known as a variable displacement pump, or what I like to refer to as a supply and demand system,which varies pump displacement based on the hydraulic systems operating requirements beyond the pump outlet. This is of course, beyond the influence of the pressure regulator valve in the system. Every revolution of the pump moves a certain volume of oil depending on the position of the slide. During upshifts, the oil volume demands of the oncoming friction element increase as that circuit is charged. When this is sensed by the oil pump, the slide responds by positioning itself in a manner that increases the amount of oil volume per revolution to satisfy the demands. This results in reductions in efficiency losses encountered when a fixed displacement oil pump and similar pressure regulation valve and spring system is in use. Although all unused oil is recirculated to the sump with both systems, less is moved under low demand operation due the ability to control volume or output per revolution within a variable displacement system. This is where the improvement in efficiency actually occurs. Now with that being stated, the higher the oil pump spins, the less time the system has to respond with increased volume by the re-positioning of the slide during a high rpm shift when the oncoming friction element is taking a "gulp" of output oil. If the pump slide springs are not matched to the projected operational rpm of the oil pump, the size of the boost valve diameter in use, oil filter and pick up and the list goes on the greater the pressure drop that will occur during high rpm upshifts ,and this is definitely a cause of concern due to the reduction in friction element capacity incurred as the pressure drop takes place. Also it causes the slide to bounce between its stops which occurs during changes in demand cycling of the slide and this often results in sudden slide fractures/failures. Properly calibrated springs keep pump volume high during desperate times reducing slide cycling, and allows the excess oil volume to be handled by the pressure regulators version of "return to sump" evacuation. All this means the slide goes nuts with stock parts beyond 5000 rpm. Install a pressure gage and see for yourself. There are huge difference with just nothing more than a filter change.

Chris thanks for taking time to answer my question with such a great detailed post.....this is exactly the info that
I was looking for and your explanation helps me to understand.

The trans was currently being used successfuly in a high 9 second build that Vince did for me and the new combo
will be a completley different strategy and set-up looking for 9.0/150mph. i should probly just make the switch to a 400
But I want to explore the possibility and what is needed to possibly make the 200 work.

I have seen the wild pressure fluctuation that you described on a TR as soon as the power came on the pressure gauge would cycle rapidly and never got the bottom of that issue as the guy sold the car before it got fixed.

I have your 200 book and a bunch of your parts in my 2 200r4 trannies.
Thanks for supporting the buick sector and for sharing your knowledge.

Would you have the pieces available to modify the pump and regulation system to allow Hi rpm operation?
I can call next week. Thanks again.
 
I have slide springs which match the .555" boost valve and most pressure regulator springs, however if you are using the .500" boost valve the use of the slide spring that comes in the TRANSGO hi rev pump kit ($12.00) available everywhere will get the job done. You can use this kit with the .555" boost valveby installing the OEM inner spring (if present) from the 2004R slide inside of the TRANSGO outer spring and it will yield similar results.
 
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