TH400 governor mod

[N360LL]

Does anybody have the article on changing/ trimming the fly weights in the shift governor? I used to have it in the book with the 70 Stage 1 one the cover but I either lent the book our or lost it . Anyway, the article is about trimming the secondary weights to change the shift points. I have one that shifts at @4100 rpm now. I'd like to move it to @5100 rpm. The pictures showed how much to trim in order to get it close. Also, does anyone have a source for the correct style pins to use instead of nails from the hardware store?

[DaWildcat]

Maybe these will help?

http://www.nastyz28.com/forum/showthread.php?t=62163
http://www.dragracingonline.com/tech...vi_9-bm-1.html
http://www.indianachevelles.com/news...ter/page2.html
http://www.chevelles.com/forums/showthread.php?t=67695
http://www.v8buick.com/showthread.php?t=134999

Devon

[N360LL]

Thanks for the help. The picture of the 5k weight is exactly what I needed. I can settle for nails.

[DaWildcat]

I can settle for nails.

Glad to help, and that's what we all use anyway.

Devon

[LARRY70GS]

I have used the B&M kit several times. Makes changing weights and springs easy. It is time consuming testing for sure, but the results are worth it. I recommend modifying a second governor, that way you can always go back to what you had. Once you have removed material from a weight, you can't put it back. There is no absolute recipe for a certain RPM shift, all combinations will react differently. That is why I recommend the B&M kit. Before you start modifying things, make sure your kickdown is connected and functional. Without the kickdown, the trans will shortshift for that reason alone.

[msc66]

Larry,

Will it short shift at WOT or just cruising? My car didn't come with the th-400 so I don't have the wiring to hook it up. Anyone know how to do that?

[DaWildcat]

Mike, what car? The early cars had transmission detent switched on the throttle linkage next to the carb. Later cars had the switch on the gas pedal linkage in the passenger compartment. If you try some searches here for "kickdown" or "detent" you should find what you need.

Devon

[copperheadgs1]

You need to buy a big block engine wiring harness and just plug it in on the trans. Then you need the big block gas pedal bracket and the switch that attaches to it. The under dash wiring should have the connector already there but taped up unused. Bet you did not know that. I think Mike garrison may make the gas pedal bracket or I have some used ones for sale. This is if you want it stock. well worth the effort. The biggest expense is the engine harness about $160

[LARRY70GS]

Larry,

Will it short shift at WOT or just cruising? My car didn't come with the th-400 so I don't have the wiring to hook it up. Anyone know how to do that?

WOT

[N360LL]

I did the mod and now it shifts at 4800 rpm. Much better, but now I'm not sure if I should raise the speed a bit more because I found my dyno sheets and it makes more hp and torque above the 5200 prm factory redline. My dyno sheet goes all the way to 5800 rpm. If a raise the shift point then I can put the engien back in the fat part of the torque curve on the 1-2 shift and the 2-3 shift.

[LARRY70GS]

I did the mod and now it shifts at 4800 rpm. Much better, but now I'm not sure if I should raise the speed a bit more because I found my dyno sheets and it makes more hp and torque above the 5200 prm factory redline. My dyno sheet goes all the way to 5800 rpm. If a raise the shift point then I can put the engien back in the fat part of the torque curve on the 1-2 shift and the 2-3 shift.

The stock Stage 1 shifted at 5200 RPM. Raise it. I have my 1-2 at 5500, and my 2-3 at 5400

[DaWildcat]

Experimentation with shift points at the track is the best way to figure this out, then modify the governor accordingly.

Devon