Are the shift valves larger on a perf valve body?

[bry593]

I noticed that the TV valve plunger is larger on a CZ valve body. This has me wondering if the shift valves are larger too. If this is true, dropping a CZ or BR governor into a non-perf 2004R should move shift points completely out of the RPM range.

Questions:
1. Why is the TV valve plunger larger?
2. How come GM eventually put a spring under the TV valve?
3. Are the shift valves larger in a perf VB? If so, what would happen if a CZ or BR governor was used in conjunction with a non-performance valve body?

By the way, I picked up a copy of "Principles of Operation" and have developed a pretty good idea of the function of each valve and spring, although the section on planetaries hasn't quite stuck yet....

Many thanks,
Bry

 

[WE4]

answers...heheheh

1. Why is the TV valve plunger larger?
Plunger and tv are larger. This is "balance" the tv cirucuit vs modulated pressure. The land on tv valave that controls psi is smaller on cz and brf and 1 or2 others.

2. How come GM eventually put a spring under the TV valve?
Eventually? They always had one on 2004r. 700r4 did not.

3. Are the shift valves larger in a perf VB?
No, they are smaller

If so, what would happen if a CZ or BR governor was used in conjunction with a non-performance valve body?

It will never shift at WOT if you did that.

Bruce
WE4
www.PTSnctb.com

 

[bry593]

just when you think you're starting to figure things out...

Thanks Mike,

I had it just bassackwards of what you said. Definitely not an intuitive thing, the larger valves should shuttle at a lower pressure. Must have something to do with shift spring and TV modulation.

Anyway, this raises two good points for anyone working with a low perf trans.

1. Don't use the BR gov unless you get the BR VB.
2. Progressively lighten your existing gov by drilling holes in the weights, testing at WOT and repeating until desired shift RPM is achieved.

One more question:
1. If only one part was changed on a low performance trans, would the most benefit come from changing from a low performance pressure regulator spring to a BR spring (from 60 to 70psi)? It seems as though this would have the broadest affect on performance, i.e. raise the shifts points, increase clutch and band pressure, as well as increase TV pressure.

Bry

 

[WE4]

Yes you are right

First.....Mike? Mike who?


Second,
we run alot more pressure than that. I like to see 120 or so at idle. Also we run 250-260 at wot tv

But that is me.

Bruce
WE4
www.PTSnctb.com

 

[Clay Thompson]

Valve bodies--CZ versus BR

Are the CZ and BR valve bodies themselves identical so far as the size of the "holes" in the casting?

What other letter code 200 4Rs have the "good" valve bodies?

Mike, excuse me Bruce, PTS has a .50 boost valve and a .40 on its website http://www.ptsnctb.com/ that provides more boost pressure and, as I understand it, these go in the front pump.

Two questions;

What does the .40 boost valve do?

Would any code 200 4R benefit from the use of these valves without any other modifications?

 

[blackplague]

GUILTY OF BEING A MIKE!!

CLAY,
THE .400 REVERSE BOOST VALVE INCREASES THE PRESSURE IN REVERSE {QUICKENS THE REVERSE ENGAGEMENT} AND DURING A L1-L2 MANUAL SHIFT. ANY 200-4R OR 700-R4 WILL BENEFIT FROM A .500 TV BOOST AND .400 REVERSE BOOST VALVES.

I THINK THAT MOST,"SHIFT KITS" COME WITH THE 80 PSI GREEN SPRING FOR THE PRESSURE REGULATOR VALVE {I COULD BE WRONG THOUGH}.

DAMN, I just noticed that i had my caps lock button on. Sorry for shouting, i didn't feel like retyping.

 

[bry593]

just when you think you're starting to remember who's who....

You guys are killing me....

I knew who I was writing to, it just came out Mike... That's all. By the way Bruce, it could have been worse..... I could have called you Greg....

Bry

 

[WE4]

LOLOL

Mike, Greg, or Bruce , all is ok. What a bitch to have all that talent eh?

Now, if you would have called me Sally, That might be upsetting..LOLOL

And the boost valve question was answered very well.
It boosts pressure in manual 1-2 and reverse.

Good Luck.
Bruce
WE4
www.PTSnctb.com

 

[MeanBuicks]

Re: just when you think you're starting to remember who's who....

Originally posted by bry593
By the way Bruce, it could have been worse..... I could have called you Greg....

Now THAT would have been a compliment!

 

[Clay Thompson]

CZF vs BRF vs other similar VBs

Thanks for answering part of my inquiry but a slip of a name got the rest of the question off topic regarding valve bore sizes in various valve bodies.

Last night I compared BR, CR, CZ and OG valve bodies and all the casting holes are bored the same diameter--a KC has one casting hole at the rear that is larger so it can never be a BRF. Does anyone know what other VBs have the small bore diameters associated with high performance?

I have not disassembled the valve bodies yet--awaiting expert guidance--but would like to know what internal characteristics to look for and how to turn an OG into a BR. The endless quest to turn lead into gold!

PTS has pump modifications to improve performance. Bruce, do you also have VB parts to improve performance? The PTS website does not really explain parts applications. Do other companies have 200 4R VB upgrage/tuning parts? I've been searching the web and all the car sites for information--TurboBuick is hands down the best source of 200 4R technical information. I have cataloges ordered from every source that deals with transmissions and may find additional information from those and I've searched this site.

Regarding this site, there is supposed to be some detailed explaination regarding pump modifications that just is not here. Did it get gobbled up in the server failure? If yes, is there a hard copy available?

 

[WE4]

Yes Clay....You are correct

It did get lost in the crash. However the good news is I have rewritten and it will be up early March . Look for it as an update to the strengthening the 2004r post. I have been writing a little bit every night so I should have it ready soon. As for the bore sizes , they (the HP ones lets say) are smaller in land diameter. The outer bore is the same but the shift valve is a little different. Plus the exhaust circuits are a tad different too