[joshp83]

weights and gear pitch is but body the same

[THERACER]

so a 350 governor will fit and work in a 700r4.
thanks , learned something new.

ROGER

[revspan]

Well, the transmission is working fine at part and mid throttle. Unfortunately, at WOT, it still hangs at the rev limiter(5500RPM).

I think that I may pull that limiter chip and replace it with a 6000rpm chip to see if it may shift after 5500rpm. The engine has been dynoed and power falls off after about 5300, hence the 5500 limit that I had in the ignition system.

As I understand, WOT shifts are controlled via valve body......Is this for sure?......is there anything else that could impact WOT shift RPM?

Looking for a knob to turn

Thanks!!!!

[revspan]

O
Another update. Made a small adjustment on the TV cable...slight loosening. From a dead stop, at WOT, it would rev to 6000....bounce the rev limiter. Then when revving up, it runs right up to 5800, shifts fine and then is on to 3rd, which goes fine too.

So, I am thinking that I can make a small adjustment in the springs and weights to do the final tuning.

One other issue is that I would like to solve is a shift from 1-2, under light throttle, that is too quick. Could this be due to the light weight, and the 4.30 gear? Is there a fix for this? I already have the lightest springs in the governor.....

Any ideas?

[revspan]

Ok...I have now pulled the governor and added weight.

Before and after RPM shift points

1-2 shift. Was 6000 RPM, which is on the rev limiter. Need to let off to shift
2-3 shift. Was 5900 and stayed right at 5900.
3-4 shift. Was 5900, and dropped to 4700.

So.....I am not sure how I can use the governor to move all of the shift points. Seems that the governor is having a big effect on higher gears. If I continue to add weight, I will lose a reasonable shift point in the 3-4 shift.

Also, I "could" simply lift a little during the 1-2 shift, but I plan on a nitrous shot that will rely on a micro switch detecting WOT, so lifting isn't what I would like to do.

Really looking for some ideas here... Thanks in advance.

[revspan]

Well, bit the bullet and dropped a new "corvette" governor in. Wot shifts are now:
1-2. 4000
2-3. 4300
3-4. 3700

So, I still have some variation in shift points, but I am back under the rev limiter.

Tomorrow I will "sneak" up on an rpm that will keep me around 5500rpm

BTW, I did get advice from a local transmission shop owner that said to forget the governor kit, and simply grind mass off of the existing weights. He said tha the kits work for th350s, but are more trouble on the 700r4.

[revspan]

Well, the mystery is solved. I got so frustrated after 18 random tries that I took the time measure the spring pressure of all the springs and spent time studying all of the combinations that I had tried. After all this work, here are the conclusions that anyone doing this MUST take into consideration.
1) springs can impact shift RPM just as well as weights. Don't make the mistake that weights alone determine rpms.
2) springs must be matched to weights. For example, you can have two weights and two springs that will behave MUCH different if you simply switch the springs and keep the weights the same.


In the end, I got my combination right on with a 1-2 shift at 5700 and a 2-3 shift at 5800. I started with 4000 rpm wot shifts and made most of my improvements by changing springs and dropping one of the weights.

Hope this helps someone...

[302 Z28]

Originally Posted by revspan

In the end, I got my combination right on with a 1-2 shift at 5700 and a 2-3 shift at 5800. I started with 4000 rpm wot shifts and made most of my improvements by changing springs and dropping one of the weights.

Hope this helps someone...

Been following your thread, glad you got it ironed out. Could you possible post what springs and weights you wound up using?

Thanks
Vince

[SSedan64]

Unless you're running the same rear gear ratio, His results/combos may not help you.

[302 Z28]

Originally Posted by SSedan64

Unless you're running the same rear gear ratio, His results/combos may not help you.

I'm fully aware of that, just trying to compile a database.

Vince

[THERACER]

i m running the same, what s the setup please ?

thanks, roger

[revspan]

NP...here is the final combination that I used. For the sake of addressing variation in different kits, I will also give some of the values that I measured for comparison.

Regarding springs. I took two measurements. First was at a compressed height of 0.25, second was at a compressed height of 0.35.

I used:
.25" .35"
Green spring 450g 350g
and
Black spring 1050g 850g

FWIW, stock "corvette" springs at 0.25" are 380g and 1400g. The kit has springs range from 290g to 1050g.

I would recommend that anyone tuning their governor find a small scale and measure their springs BEFORE they change them.....otherwise you could, will be flying blind.


Weights:

Stock, which is 0.5oz/14.2g
"B" weight from kit which is 0.45oz/12.75g

FWIW, weights from the kit ranges from 5.6g to 14.2g

Final combination had Green spring with "B" weight, and Black spring with stock weight.

I can't stress enough that you need to keep good notes during tests. It took some work to see the patterns in what needed to be changed to get this right. Now the thing drives like a dream!

So, in the end, I increased pressure of light spring, reduced pressure of the heavy spring to solve the problem of drastic differences in shift points from 1-2 to 2-3 shifts.

again.....if you don't know where you are starting, you are going to get frusterated. I sure was!