I have an acquaintance that would like for me to assemble a solid th400 for him. It's gonna be an 1/8mi bracket car.

Most th400's I see in bracket racing use a manual valve body and an rpm-triggered air shifter.

This fella is pretty sure the stock governor can be used to nearly the same result and I just dont see it.

I'm interested to hear some people chime in that use, or have seen used, the stock governor to any sort of success.

If I can get him to see the light, I had planned on pointing him to the CK brake/VB, as that's that last one I used with good results. Opinions on that are welcome as well.

This is gonna be a pretty light NA car. Borderline Powerglide territory imo

 

The governor definitely can be used successfully for repeatable shifts.
@Jake's Performance builds a th400 valve body that is transbrake and uses governer to auto shift as you go down track.
You don't get much more consistency than that!

Modify the governor weights and springs to get desired shift point and it will be pretty repeatable and reliable.

I'm working with Jake on a computer shift th400 valve body that uses solenoids in the pan...but it will be a minute before I get any real traction on that one haha

 

Transmission temperature has a lot to do with consistency. You want to keep it pretty much the same temp to get it to be repeatable.

 

Maroon Monster gave you perfect advice.

Since I know you have been hands-on with your transmissions now...

Take a look at this Governor kit from Superior Transmission.



Superior Transmission part #K018. Hyper-Link: Click Here
Once you have done one of these, you will get a feel for the weights and springs.

You can take photos of the "physical weights" and put them on a "Postal-Scale" to record how heavy they are (and how they change the desired RPM).
In the future you can reference this information that you record; and modify the governors yourself with out purchasing parts (most of the time).

 

In the 1/8" mile...

Depending on power level; you may need a really good amount of gear ratio.
If the power is up there... you will then have traction issues.

Sometimes going to a 2-speed Powerglide can work-out better for traction/ performance/ consistency.
I would ONLY go to a 2-speed THM400 if the HP is way up-there.

 

Doug...

I also forgot to mention that the gears on the governors are bad about wearing... especially if the case bushing is shot.
The end-play (side to side of the case) also should be established.

I do not know what the instructions in that kit go over... or don't go over.

Check the teeth on your gear and the end-play... let me know what you find.

 

okay will do. it looks like we are going with that jake's valvebody maroon mentioned.

With some 80e hard parts I have on the shelf and two core 400's (an early BOP and a later truck model) he's dropping off on the 12th, I should be able to make up a solid unit for him. I think he's looking for mid 5's (with room to grow of course) in the 1/8th on roughly 600hp and a 2500lb car

any suggestion on frictions? In my fixed line pressure CK-style tranbrake 80e's I usually use the green raybestos graphitic waffles in the IM and direct and GPZ in the forward. A wave in the IM and forward. normal steels. Shifts reasonable on the street and doesnt break stuff at the track.

I am keen to try those allison partial waffles you mentioned if this is a good application for them.

 

What type of Intermediate Sprag are you going to build with?

 

my plan was to use the whole 80e direct drum & 34 element sprag IIRC it fits in there nicely. big cubes so hopefully relatively tame rpms

 

Then you can use the frictions and steels that you want, EXCEPT...

For the intermediate clutch:

-Use a 4L80E Borg Warner High Energy friction with a Kolene Turbulator steel.
OR
-Use a THM400 Borg Warner "Waved" tan paper friction (OEM) with a Kolene Turbulator steel.

Both of these Intermediate clutch arrangements (with some type of waved steel cushion plate) will help keep that 34-Element (4L80E) Intermediate Sprag alive (even with decent HP).
Make sure an aluminum intermediate clutch piston and 12 return-springs are also used.

 

It is NOT critical for "Non-Competition" Trans-Brake valve-bodies or usage...

But when using a Trans-Brake here, try and get an early THM400 Direct drum that has BOTH sets of feed passages in the drum itself.
The later THM400 and the 4L80E Direct drums ONLY use ONE set of feed passages.

 

is a graphitic friction too grippy for the intermidiate and the cellulose friction will allow a little slip to keep the sprag alive?

I just sent an 80e unit out that a customer INSISTED on using graphitic in the intermediate, heavy truck making ~ 600hp and he says its perfect....just hoping that sprag isnt a grenade with the pin pulled.

I always use a wave in the fwd and intermediate clutches.

 

Not necessarily...
There are other factors of course.

With the 4L80E (with the accumulator valve-train stock) and a mild 2nd feed orifice in the separator plate; it is most likely fine.

I personally change the 4L80E accumulator valve-train to resemble one of the more aggressive versions of the THM400 accumulator valve-train.
The THM400 had several different accumulator valve-train configurations... and change the 1-2 shift in several ways.

Over all... just make sure that the 1-2 shift does not get too aggressive (this will protect the sprag from unnecessary shock).

You can also help the sprag by supporting the direct drum (with a press-fit sun-gear shaft and/ or roller-bearing center-support).

 

in the CK style brake I use in the 80e the 1-2 accumulator is deleted, but I keep the shift orifice around .080 and it's going good so far. 10.14 at 135 on friday, even though I blew the coupler off the intercooler and went though the traps on only 10 psi

I will set this 400 up with HE frictions in the IM and graphitics in the fwd and direct.

 

That sounds fine.

Are you familiar with the different THM400 Accumulator Valve-Train arrangements?
I do not know what Jake has in his Auto-Shift Trans-Brake Valve-Body...
Let me know if it uses the 1-2 Accumulator ; and which Accumulator Valve-Train is in the Valve-Body.

If needed; I will give you a new arrangement for the Accumulator Valve-Train.

Also, post photos of the Induction tubing/ piping... When designed correctly, there should be no "Blow-Apart" joints.
Let me see what you are using, and possibly give you a recommendation...
I build a stupid amount of Turbo cars, every year now!
In the last 5 years... my customer demand for Turbo engines VS Super-Charger or Nitrous-Oxide engines has more than quadrupled.

I even purchased a substantial amount of equipment to rebuild and re-balance Turbo-Chargers and Centrifugal Super-Chargers in-house.
I had no idea, when I started doing in-house Turbo work...
That I can repair/ rebuild Turbo-Chargers for my customers for substantially less than even the Chinese Knock-Off units cost.

I wish Automatic Transmission work was as profitable!!!

 

oh i just didn't seat a coupler all the way onto the intercooler during a 4 hour motor swap earlier this year