200R WOT upshift RPM

[Jvette73]

Its not a G/N trans but it is a 200R. I know you Turbo Buick guys have the best expierence with this trans. I just swapped in the 200R into my 73 Vette. Everything is great and the tranny is awsome. One thing that could be better is the WOT upshift points. Right now, when placed in 4th and allowed to upshift automatically from a full throttle dead stop, the trans will upshift at 4000rpm. I would like it to upshift at 5000rpm. I know this will mean working with the govenor. My question is, can the govenor thats in the trans be modified to shift at a higher rpm or do I need to experiment with different factory govenor units? The TV cable setup has been fine tuned for agressive behavior with a custom kit. It has been verified that it completly depresses the TV into the bore in the pan at WOT. I know I could just shift it manually, but after being modified for the extra detent, the stock vette shifter has a very indecisive feel. Its very easy to throw it past 2nd into 3rd. I would rather have the trans upshift automatically at the desired rpm of 5000. Thanks in advance for the help. My vette is no slouch but I always treat the Turbo Buicks with the utmost respect.

 

[Geerrhead]

Lighten the small weight on the governer.

 

[Jvette73]

Thanks Geerrhead. I suppose I would need to first remove the govenor from the trans before working on it? Ok, drop the pan and remove the cover plate at the back of the trans...then what? Does the gov just fall out? Is it retained somehow? Im pretty handy with tools. What would be your guess as to how long this job should take? Thanks for your help. John

 

[Geerrhead]

Remove 13 mm boltss from the pan.
remove 4 13 mm governer housing bolts
pull governer down, may come out with the cover
weigh the governer
drill hole in small weight
weigh governer
road test
repeat as needed
prolly take 15 minutes each time

 

[Jvette73]

Sounds simple enough. I think I can handle that. What size bit should I try for the first hole? Shifting up at 4k WOT now. Would like to shift up at 5k WOT.

Nother Q for you too. Does the govenor run off the output shaft of the tranny? If so, then the output shaft is controlled mainly by vehicle speed, except in the case of wheel spin. Hence raise the vehicle shift speed...raise the shift rpm is the byproduct. Is this a correct assumption?
I appreciate your time and help. John

 

[77 cruiser]

Start off with 2 - 3/16 holes on the outer edge , trial & error.

Jim

 

[transfixleo]

"Nother Q for you too. Does the govenor run off the output shaft of the tranny? If so, then the output shaft is controlled mainly by vehicle speed, except in the case of wheel spin. Hence raise the vehicle shift speed...raise the shift rpm is the byproduct. Is this a correct assumption?"

You are kind of looking at it backwards. The Governor is telling the tranny how fast the car is going via pressure generated as the output shaft spins. Changing tires or axles will change the MPH that it shifts but the engine RPM will be the same and that is what you are really trying to change. By lightening the Governor weights it takes higher output shaft RPM to get the same pressure out of the governor and thus higher shift points. The tranny you have is going to be harder to get ALL shift points where you want them since the GN type VB actually has different SIZE valves that work in harmony with the governor to get the desired shift points, not just WOT but part throttle where most people drive at. The higher you go to get WOT shift points you may not be happy with the part throttle but for now that is all you can do unless you can come up with a GN or Monte SS tranny.