School me on a transbrake

I am seriously considering a transbrake.

What are the things to consider?

The transmission has been fairly well built with a good drum.
Street and strip



Info
1968 Road Runner
Procharger
3770 lbs

Which rear end is in it? What size drive shaft and which type and size U joints now

727 I assume?

CAb it’s a Dana 60
3.50” chrom moly drive shaft
Iirc 1350 ujoints and a strange forged yoke. ( I just swapped as I cracked some bearings in the unjoint and twisted the yoke last year)

Yes 727. billet steel drum
Good sprag and parts
Could use a billet output shaft

Converter also has to be considered. Some are built without an anti-balloon plate (such as a Turbo Action "J"), and a transbrake will destroy them in short order.

Brian

I have not race a727 with a trans brake for a long time so I have no real world current experience with one of todays trannies, my last race car had a glide in it and I would launch it at WOT on the tans brake which was between 5400 up to 5800 RPM depending on the track elevation and D.A., shifted between 7000 up to 7300 RPM, which was 2.0 MPH faster at the same ET
On your deal it will depend on what RPM you want to launch the car, testing different ones will help find out what your car likes
It looks like your car should hold up without parts breakage

Things to investigate
- Converter anti ballooning plate
- a bleed hole in the front Drum (facilitates quicker releases)
- Good quick release Brake Button
- Transmission shield
- Sprag (doesn't have to be a bolt in but make sure its in perfect condition)
- Move Vent front Pump cover to tail housing
- Good front yoke
- Rear Planetary set - likes to rip out the spline

Thats my

just my but I'd add a pro rear gear set to that list

I'm sure you meant front.

Your converter will also need a steel stator, ask me how I know. My 8” converter had an aluminum stator and it disintegrated, wiped out the whole converter. It’s caused from heat cycles. Wise I saved pics of it.

Things to investigate
- Converter anti ballooning plate. 👍
- a bleed hole in the front Drum (facilitates quicker releases)I assume this can be done when the brake is installed?
- Good quick release Brake Button do you normally put this on the steering wheel?
- Transmission shield👍
- Sprag (doesn't have to be a bolt in but make sure its in perfect condition)👍
- Move Vent front Pump cover to tail housing. will need to check
- Good front yoke
- Rear Planetary set - likes to rip out the spline. no idea… any more details on this ?

Thats my


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I just bought some new3.73 gears. How long do pro gears last. Please note that this is a street car too

I second what everyone says. The billet drum and ultimate sprag are the biggest concerns so since you already have them, youre in good shape. I will add, put a steel front planetary in the transmission, aluminum stock front planets are know to strip out the splines. The bleed hole to the front drum needs to be done. Some put it in the piston but its recommended to do the drum. Once you do that you need to move the vent to the rear because with fluid escaping the drum through the bleed hole can cause a leak out of the front pump vent. I haven't experienced that personally but I know that is the theory. If you put the bleed hole in the piston opposed to the drum, you may not have to move the vent.

Definitely a steel stator in the converter as the aluminum one will absolutely explode. Being that its a street car as well, your gears are "harder" than a pro gear, so you may want to consider that before installing the trans brake. My richmond pro 4.56 gears have over 200 runs on them. My US 4.30 pro gear both sets lost pinion at 200 runs almost exactly. The richmond seems to be happier knock on wood. Like any race car part, they last until they don't.

As far as a button goes, I have mine on the steering wheel, but know others prefer it mounted elsewhere away from the wheel.

You are going to want to wire in a relay so that when the transbrake is activated, the line lock also activates so the car does not creep. If you don't wire in the relay which activates the line lock when the trans brake is activated, just stage at low of an idle as you can before hitting the button to avoid the least amount of load on the chassis. Once you activate the trans brake, if you are at a high idle, without line lock, the chassis will relax and car will rock forward.

What's the doohickey bolt in the rearend? Some sort of sensor?

In all honesty, unless you're seriously going to race I'd not bother with a brake.

I've had to switch to the harder but more brittle, street gears too as Pro Gears in 3.73 (lower numerically than 4:10) are no longer available for a Dana 60. I have only done a dozen passes on them but I intend to inspect every season. I footbrake BTW (best 60ft is now a 1.29), a good 9" type rear is on the list for the future.
Below is a Dana 4:10 street gear which had around 120 passes before they let go, about 90% of the teeth were like this and the discoloration on the breaks pointed towards an inclination to believe that they may have been cracked for some time.
The issue with the transbrake is the backlash isn't taken up throughout the drive train, like it can be on a footbrake and this adds to the "shock" on the rear gear as the backlash is taken up. The Soft pro gears give a little but the caveat is they wear quicker. How quickly will depend on driving style and how well they were set up, the whine will let you know when they need replacing

I would have to agree w/ this. I have a transbrake in my car, but I'd rather footbrake it. Doesn't make much difference in how it runs. I did it simply for running pro tree classes. I suck on the tree anyway so, lol.

I put a brake in the Belvedere soley to run a delay box. It didn't improve ET's at all. Back in the 90's, they decided to run pro and super pro as one class. It didn't take too long to figure out that I couldn't hang with the delay box crowd. I bought a brake from Joe at TranzAct. It worked great (still does). Bought a cheap delay box and went racing. At first, I let go of the button at the first flash and mashed the pedal on the bottom bulb, or I thought I did. The first thing I broke was the crankshaft. I eventually broke everything in the drive line, one piece at a time, before finally getting a 2 step. I don't know what RPM I was actually leaving at before, but it was sure way higher than the 3000 chip I ended up with. I'll also never forget the big, bold warning/disclaimer at the bottom of the instruction page. SERIOUS INJURY OR DEATH MAY OCCUR. Oh, the good old days.

Yes I did

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I 3rd on all the recommendations. Also with the transbrake, I believe most requires you to hold the button to use reverse
So if may make driving on the street a pain

I wouldn't and don't recommend using any Pro ring and pinion gears on street or street and strip car
They're to brittle and won't live long on the street

It's the other way round, street gears are hard tempered and brittle. Pro gears are soft and wear out quick.

https://www.dragzine.com/news/do-you-need-street-gears-or-pro-gears/

I wired my t-brake to the reverse light wire on the neutral safety switch. Work great.

I like a break. Makes the car a little funner. Wheels up launches and snap your neck in an instant.

My car has a TranzAct vb and it's lighting fast. (Valiant)
Ka-Blue-E has a Bruno drive, it's even faster ! (Co2 trans break)
I can go red in both cars on a pro tree seeing Amber's

Racepak sensor.

Would I benefit from a transbrake?

I currently leave off idle.
I push through my brakes too easily

It is a Procharger car on I have zero boost at idle and I assume I could bring up the rpm’s with a brake

Only one way to find out

Looks like you need a looser converter by looking at your 60ft . , then see what a trans brake would do, your ET is WAY better than what your 60ft shows.

The yellow line is the rpm
The blue line is the throttle

This is how I launch off idle

Any thoughts on the converter ?