Setting 200R4 WOT Shift Point
Thread Starter
Drifting
Joined: Sep 2004
Posts: 1,625
Likes: 4
From: Miami FL
Setting 200R4 WOT Shift Point
I would like a second opinion to make sure all is good before I officially pull the trigger on a 200R4 swap. To set the WOT shift point is done by modifying the governer weights and springs. Understood. How difficult is it to dial it in so that it ****s at 6,500rpms? Also will it shift at 6,500rpms in every gear? 1-2 & 2-3 & 3-4? I ask because it is not electronically controlled and understand line pressure may affect shift points and this changes depending on what gear I in?
Also how are part throttle shift points determined? Will having a 6,500 WOT shift point make normal driving part throttle ****s not enjoyable?
Btw. Manually holding the shifter to 6,500rpms is not an option for me otherwise I will stick with the 6 speed. I want an automatic that I don't have to touch anything with it shifting each time at same shift point and locking torque converter automatically and unlocking when hit the brakes, downhift instantly into right gear and then ride put that gear to 6,500rpms with the gas pedal floored.
Also how are part throttle shift points determined? Will having a 6,500 WOT shift point make normal driving part throttle ****s not enjoyable?
Btw. Manually holding the shifter to 6,500rpms is not an option for me otherwise I will stick with the 6 speed. I want an automatic that I don't have to touch anything with it shifting each time at same shift point and locking torque converter automatically and unlocking when hit the brakes, downhift instantly into right gear and then ride put that gear to 6,500rpms with the gas pedal floored.
Le Mans Master
Joined: Oct 2006
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From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
The simple answer is that at WOT the TV system boosts pressure and the shifts will happen later. Changing the weights/springs on the governor will change all the shift points too.
Overall, line pressure is controlled by TV, and is routed to the governor along with the shift valves and lube circuits. Line pressure is on one side of the shift valve and governor pressure is on the other- when the governor pressure overcomes line pressure the shift valve moves and the next gear happens.
Pretty basic stuff, but them's the basics.
Tailoring the governor weights/springs on a 2004R is kinda tough- the governor is in that rearmost "hump" on the pan- drop the pan to get at it.
Overall, line pressure is controlled by TV, and is routed to the governor along with the shift valves and lube circuits. Line pressure is on one side of the shift valve and governor pressure is on the other- when the governor pressure overcomes line pressure the shift valve moves and the next gear happens.
Pretty basic stuff, but them's the basics.
Tailoring the governor weights/springs on a 2004R is kinda tough- the governor is in that rearmost "hump" on the pan- drop the pan to get at it.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
I'm just not so sure that I'd feel at all comfortable sitting on top of a 200R4 that is being revved to 6500rpm. 
I don't believe that it was ever designed for that rotational speed. Certainly, the converter would need to be replaced with a unit capable of those rpm's. You might want to do some research on the limits of use on a stock 200R4.
I don't believe that it was ever designed for that rotational speed. Certainly, the converter would need to be replaced with a unit capable of those rpm's. You might want to do some research on the limits of use on a stock 200R4.
Thread Starter
Drifting
Joined: Sep 2004
Posts: 1,625
Likes: 4
From: Miami FL
It would be a Level 3 unit from Bowtie Overdrives with all the beefed up components including sfi bell housing to handle 550 crank HP and lots of abuse. Not cutting any corners on quality. Just need to know if it can be done the way I want to use it. Now the part about spinning it to 6,500rpms on the trans internals itself is interesting. I have googled and found lots of installs but nothing specific to how I am trying to use this trans.
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
7T1 has a really good point!! I've built a few 2004R's when I was playing like a dealer tech and most of them were in Granny's car. I really doubt Granny was turning her Caddy to 6500. (Little Old Lady from Pasadena???)
But GM did put that trans behind the 3.8 in the Buick Turbo GN too and I know some guys are pulling some pretty big HP numbers too. I do know it had a different valve body and some HD clutches. Memory kinda sucks, but I suspect they did them like GM did the 700's- different amounts of clutches in different locations depending on application.
But GM did put that trans behind the 3.8 in the Buick Turbo GN too and I know some guys are pulling some pretty big HP numbers too. I do know it had a different valve body and some HD clutches. Memory kinda sucks, but I suspect they did them like GM did the 700's- different amounts of clutches in different locations depending on application.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
That's what I would expect; that GM had certain components within that tranny which they beefed up and use in those applications where performance was expected. GM never put more expensive parts in all production units of a particular model, just so those performance vehicles would be safe....they always upgraded only those that required it. The real concern is the larger, heavier rotating components in the tranny: certainly the converter is critical with all the mass of oil in it and its thin walled construction; then the clutch housings and planetary carriers....anything heavy that rotated. The stress on those parts increases exponentially with rotational speed.
