Higher 1-2 Shift Needed

[nightrain]

Last season, I ran a trans brake and finally got the car tuned decent enough to run a very high 10. This winter I'm adding some safety gear (roll bar, trans blanket, C-clip eliminators) to stay legal. While I'm at it, I want to increase the shift rpm at the 1-2 shift. The trans is shifting itself at 4800 rpm (1-2) and I then manually shift at 5900 rpm 2-3. Since it's a manual T-brake, I have no control over the 1-2 shift. I think Bison mentioned a while back to change the valve body to a CZ or KC.

So, if I change the VB to one of those, what rpm can I expect it to shift at?

and what else needs to be changed?

Does it just bolt in after replacing all the stuff I changed in the original VB (shift kit valves, springs, etc.)?

Where do I get a CZ or KC VB?

Lastly, will the T-brake spacer plate for the original VB work with the CZ or KC VB's as well?

Thanks!

 

[Otto J]

Last season, I ran a trans brake and finally got the car tuned decent enough to run a very high 10. This winter I'm adding some safety gear (roll bar, trans blanket, C-clip eliminators) to stay legal. While I'm at it, I want to increase the shift rpm at the 1-2 shift. The trans is shifting itself at 4800 rpm (1-2) and I then manually shift at 5900 rpm 2-3. Since it's a manual T-brake, I have no control over the 1-2 shift. I think Bison mentioned a while back to change the valve body to a CZ or KC.

So, if I change the VB to one of those, what rpm can I expect it to shift at?

and what else needs to be changed?

Does it just bolt in after replacing all the stuff I changed in the original VB (shift kit valves, springs, etc.)?

Where do I get a CZ or KC VB?

Lastly, will the T-brake spacer plate for the original VB work with the CZ or KC VB's as well?

Thanks!

With the KC VB and a stock GN govenor I get a 5800-5900 1-2 shift now.
it uses the same spacer plate,and will require the same mods to the valve body as your stock BR unit.
Some KC valve bodies have a spring in the MTV upshift valve,if so remove it also.
CK Performance should have one and will do the mods before he ships it.

 

[87GN_70GS]

Another option is to play with the spring in the 1-2 shift valve. By either replacing it with a firmer spring, or shimming it, you will increase the gov pressure (speed, rpm) at which it causes the 1-2 shift. This will be a trial and error type deal. Of course it will also raise part-throttle 1-2 shifts.

 

[nightrain]

Thanks, Otto! I'll contact Chris to see what he can do. It's his kit and T-brake in the trans.