i have a th350 and i want to get a trans brake setup but i am 100% lost.... any advice tips would be helpful... thanks!...

 

TH350 transbrakes are expensive.

Cheapest
Powerglide
TH400
TH350
700R4
Expensive

What do you want to know. Installing a transbrake is more than just changing the valve body. They all require a few internal modifications to the tranny.

When the shifter is moved into first gear, the transbrake can be activated. When in first and the transbrake is on, the transbrake moves fluid into the reverse circuit. With the transmission in first and reverse, it's locked and no power comes out the tailshaft. You can now bring the engine up to the converter's stall speed since the engine rpm won't climb any higher than the stall speed. When the transbrake button is release, the fluid is dumped from the reverse circuit and the car launches forward.

Click the link in my sig to watch my drag strip run. As soon as the lights on the tree come down, you can hear my engine pounding away on the 2 step at 4500 rpm. My converter stalls at around 6000 rpm but I don't want to launch that high. When the transbrake releases, the car jumps forward.

 

where can i get one? and is it something i can install myself?

 

No in a 350 it's not really something you can install yourself. That is, it's in the class of things such that if you have to ask, you're not ready to try it at home. A little transmission experience in general would be wise before attempting it.

Like Stephen said, what a transbrake does, is to shift the trans into 2 gears at the same time (usually 1st & reverse in most other transmissions), which locks up the mainshaft. If you've ever had a trans fail in such a way as to do that while driving down the road (shift itself into 2 gears at the same time, that is), you'd know, that the rear wheels will instantly lock up as solid as if they were bolted to the axle housing instead of the axles. Guess how I know that.....

The thing about a 350 is that 1st gear is the low-reverse clutch applied, and nothing else; and reverse is the low-reverse clutch, plus reverse. In other words, 1st and reverse at the same time, is reverse; not 2 different gears at once. So the 350 takes a little more elaborate setup.

If you want one, best to just buy a transmission from somebody regularly in the business of building racing transmissions, already set up the way you want it. Probably costs you less in the long run..... and in this case, the long run isn't very long at all.

 

I run a TCI transbrake in my car.

The powerglide is the easiest to install. Change the low/reverse clutch springs. Drill a small hole in the direct drum. Install the transbrake valve body and related parts.

This all requires a complete disassembly of the tranny.

 

well maybe i'll just stick to power brakeing at the line for now, lol... my dad has a friend who is a tranny and rear end specialist so maybe he will know where i can find a good shop to have them build me the right tranny... i guess my other option would be to go with a rock crusher 4 speed with a really good comp clutch or something.. who knows though this is my first project and i'm still learning, thanks for all the knowlege...

 

also, a trans brake is only available in a manual valvebody, thus you have to shift as if it were a manual trans, only without a clutch.

 

The Turbo Action transbrake I had in my TH400 wasn't a full manual. Put it in D and it would go through the gears as normal. Manually shifting through the gears, it would stay in that gear until you shifted.

It was also a reverse pattern shifter. Instead of PRND21 it was PRN123. It's impossible to go from 3 to N without downshifting through the gears first. I found this annoying in a race car. It was good that you could never overshift into neutral but after crossing the finish line, I neutral my tranny. Not something recommended for TH350 or TH400 trannies anyway. A forward shift valve bosy allows this and I use a ratchet shifter so it only shifts one gear at a time when I hammer the shifter forward.

All the transbrakes are designed to only work in first gear. If you're in any other gear and push the transbrake button, nothing will happen. Some valve bodies like the one in my powerglide need the transbrake button pushed for the car to go into reverse. Simply putting the shifter in reverse does nothing until the button is pushed. I simply wired an extra circuit for the transbrake through the reverse switch on the shifter.