Turbo 400 experts please step in....

[joespanova]

OK , thanks everyone for your contributions.

[ss3011]

Thinking about this a bit more . The kits you can buy just modify the secondary weights and springs of the governor . Your problem is at slower speeds that may be affected by the Primary governor weights , this is the heavier weight . I would look for a different governor that has a Lighter primary weight . Suggest you find one with a big hole drilled through the primary weight and swap it on to your existing governor . Reuse the secondary weights and springs you already have but swap on a pair of the lighter primary weights . See what the effect is to that change is . Some trans shops have used governors you may be able to purchase cheap , and maybe even the pins . We had many , many different governor weights designed , both primary and secondary . Good luck ! BTW when you adjusted the modulator , did you see any effect ?

[Mark Yacavone]

Also , you can use some T350 governor parts .Weights, springs. The top is different and the plastic gear turns the opposite way.

[joespanova]

Originally Posted by Mark Yacavone

Also , you can use some T350 governor parts .Weights, springs. The top is different and the plastic gear turns the opposite way.

OK , thanks........

[Tom Goldman]

One thing I'm surprised no one has mentioned is that most OE vacuum modulator feed lines have a restriction ,usually a crimped area in the tube to help regulate the speed in which the modulator responds to throttle changes .
Also , if you are using the short , small 2" diameter modulator , There are many different spring calibrations for different applications identified by the color stripes ,usually black ,white ,red , red-red ,red-black are common identifiers .
Each one has a different spring rating ,the external adjustment only addresses the range of that particular spring.

[Greg Reimer 7376]

Seems that the factory had its work cut out for itself fine tuning this trans to fit all the various engine combinations it found itself behind. The basic three speed planetary gearset came behind 250 horse 327's up to 400 horse plus big blocks, plus Pontiac,Buick, Olds and Cadillac, all high torque motors with various characteristics. Vacuum modulators, modulator steel line sizes, and all kinds of valve body springs all went together to make this trans work for everybody. A certain amount of trial and error is to be expected in order to fine tune it to suit a particular user. Of course, most drag cars have a manual valve body so modulators and other spring applications turn into a moot point . The age old axiom is correct here when we find that the best dyno is the drag strip. Sounds like an assortment of modulators and springs and a trip to the track for a test and tune session would be your ultimate best bet. Just don't change anything on the engine's state of tune while you are working on the transmission. Good luck on your project,thanks for introducing a subject that resulted in quite a bit of intelligent discourse.

[joespanova]

Originally Posted by Greg Reimer 7376

Seems that the factory had its work cut out for itself fine tuning this trans to fit all the various engine combinations it found itself behind. The basic three speed planetary gearset came behind 250 horse 327's up to 400 horse plus big blocks, plus Pontiac,Buick, Olds and Cadillac, all high torque motors with various characteristics. Vacuum modulators, modulator steel line sizes, and all kinds of valve body springs all went together to make this trans work for everybody. A certain amount of trial and error is to be expected in order to fine tune it to suit a particular user. Of course, most drag cars have a manual valve body so modulators and other spring applications turn into a moot point . The age old axiom is correct here when we find that the best dyno is the drag strip. Sounds like an assortment of modulators and springs and a trip to the track for a test and tune session would be your ultimate best bet. Just don't change anything on the engine's state of tune while you are working on the transmission. Good luck on your project,thanks for introducing a subject that resulted in quite a bit of intelligent discourse.

Recall , this thread is only about part throttle early shift 1-2. But good points.......

[joespanova]

Originally Posted by Tom Goldman

One thing I'm surprised no one has mentioned is that most OE vacuum modulator feed lines have a restriction ,usually a crimped area in the tube to help regulate the speed in which the modulator responds to throttle changes .
Also , if you are using the short , small 2" diameter modulator , There are many different spring calibrations for different applications identified by the color stripes ,usually black ,white ,red , red-red ,red-black are common identifiers .
Each one has a different spring rating ,the external adjustment only addresses the range of that particular spring.

Exactly , and I have the single red stripe , dual red stripe , black stripe and on and on and on , and I have no way of knowing what's doing what ......in other words , apparently I have to try everything and then MAYBE.......LOL

[joespanova]

Originally Posted by ss3011

Thinking about this a bit more . The kits you can buy just modify the secondary weights and springs of the governor . Your problem is at slower speeds that may be affected by the Primary governor weights , this is the heavier weight . I would look for a different governor that has a Lighter primary weight . Suggest you find one with a big hole drilled through the primary weight and swap it on to your existing governor . Reuse the secondary weights and springs you already have but swap on a pair of the lighter primary weights . See what the effect is to that change is . Some trans shops have used governors you may be able to purchase cheap , and maybe even the pins . We had many , many different governor weights designed , both primary and secondary . Good luck ! BTW when you adjusted the modulator , did you see any effect ?

I took it out for a test drive after running the screw in a little further.no change , at least nothing noticeable . I'll spend time with the governor as you suggest , however I don't want to change the way it acts under full throttle , now. I can see this is going to require a fair amount of trial and error.........in other words a PITA. But , I'll do it none the less.
Perhaps I should just consider a 4L80E and be done with it.