How EXACTLY does a trans-brake work on a TH400?
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From: CA
How EXACTLY does a trans-brake work on a TH400? I know its like dumping the clutch in a manual, but What is the whole concept behind it? What are the benefits? I guess I am asking how it works at the track? Would it interfere with nitrous? Do you stall up, then mash on the gas and disengage the t-brake at the same time?
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From: Ohio
It puts the drivetrain under load without the car moving...so just like pushing in the clutch. The car does not move until you release the micro switch then off you go hopefully with the front tires off the ground... 
Not a technical based answer just the facts!
Not a technical based answer just the facts! 
It locks 1st and reverse together, thereby allowing the converter to flash to it's actual stall speed (about the only way to find out the true stall of a converter). When you hit the activation button on the transbrake, it locks the two together, you mash the throttle to 100% and on your light (be it the second yellow, third yellow or the green), release the button! Instant hard launches! No, it doesn't interfere with nitrous or any other feature.
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From: CA
Originally Posted by 12secSS
It locks 1st and reverse together, thereby allowing the converter to flash to it's actual stall speed (about the only way to find out the true stall of a converter). When you hit the activation button on the transbrake, it locks the two together, you mash the throttle to 100% and on your light (be it the second yellow, third yellow or the green), release the button! Instant hard launches! No, it doesn't interfere with nitrous or any other feature.
So if I am 100% on the throttle, but it will only stall up to, for example a 4000 stall, 4000RPM - even though I am already at 100% throttle.
How would this work if I have a window switch for the spray? It sprays at WOT with the 3K pills?
Yup, your engine will not rev higher than 4000 rpms. The converter cannot slip any higher than the stall speed, so the rpms are held down, kind of like a rev-limiter. Chances are you will be spraying while sitting at the line, but it will only be for a couple of seconds ... activate the transbrake when you see the first yellow come one, or when you see both cars are fully staged.
Edit: Or you can hold your throttle to say 85-90% throttle to avoid actuating the nitrous.
Edit: Or you can hold your throttle to say 85-90% throttle to avoid actuating the nitrous.
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The Bull
Joined: Jun 2002
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From: Grand Rapids, MI
Or, you wire a relay into your transbrake to activate the solenoids only when the button is not pressed. If you spray while you are on the brake you will apply more power to the motor. As a result of the additional torque your stall speed will climb and your window switch will activate further. This is also the reason that boosted cars need to control their boost on the brake. Otherwise some cars can creep well above the proper stall/launch speed. If you are not careful with this you can cause some pretty serious damage. 
The safest and easiest way to apply nitrous to a trans brake is to wire it up correctly in the first place.
The safest and easiest way to apply nitrous to a trans brake is to wire it up correctly in the first place.
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wire up a relay for the break and nitrous so when the t break is in and the kit is on and you are at full throttle it will not spray till you release the t break! thats how its wired on my car.
Be VERY CAREFUL how long you engage a transbrake for it causes the trans temps to skyrocket HUNDREDS of degrees in seconds.
Basically the transbrake engages the car in both 1st and R byvalving the pump to both of these gears. The TC is slipping TOTALLY at that point so that is where the tremendous heat build up comes from. Some people set a 2-step to the nitrous so when the transbrake is released the 2-step will release and spray the nitrous but I dont think it would be a problem spraying on the transbrake other than wasting nitrous.
Put the car in 1st. Wait until the first yellow, engage the transbrake and floor the gas. Last yellow release the brake and hold on its gonna get interesting.
Basically the transbrake engages the car in both 1st and R byvalving the pump to both of these gears. The TC is slipping TOTALLY at that point so that is where the tremendous heat build up comes from. Some people set a 2-step to the nitrous so when the transbrake is released the 2-step will release and spray the nitrous but I dont think it would be a problem spraying on the transbrake other than wasting nitrous.
Put the car in 1st. Wait until the first yellow, engage the transbrake and floor the gas. Last yellow release the brake and hold on its gonna get interesting.
The Bull
Joined: Jun 2002
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From: Grand Rapids, MI
A trans brake loads the engine against the transmission only. The transmission is essentially put into a mode very similar to Park. Basically with 1st and reverse locked to each other, the fluid will circulate properly. But the forces will be applied equally to both gears so that you don't get any movement. This is why oil temps rise rapidly on the brake as well. That loading causes a lot of heat in the converter. If you are on the brake too long or heat rises too much you can also damage things. Whether you balloon the converter or break the trans fluid down to a point that it looses a lot of it's lubrication properties. That's why you'll see a lot of the faster cars or more competitive racers change their transmission fluids frequently. Just a preventative measure.
The abuse only comes when you release the button. Sort of causes whiplash your first time.
The abuse only comes when you release the button. Sort of causes whiplash your first time.
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From: CA
Man I cant wait - thanks for all of the replys guys.
So tach up to just before the rev limiter (mine is currently 6800 RPM) or is that too high to rev up to on the t-brake? Is spraying out of the whole any harder on the motor - stock bottem end
So tach up to just before the rev limiter (mine is currently 6800 RPM) or is that too high to rev up to on the t-brake? Is spraying out of the whole any harder on the motor - stock bottem end
The Bull
Joined: Jun 2002
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From: Grand Rapids, MI
You won't be able to tach up that high. If you have a 4000 stall converter it will only climb to 4000 and stay there. No rev limiter or anything. It will just magically hold that RPM until you let go of the button. After you let go it will flash a little higher. That's more noticable on spray.
On the nitrous question.
I have a Harlan 2-step hooked up to transbrake and also the nitrous system. The 2-step is set just below the stall. It prevents the nitrous from activating. Once the T/R is pushed in, it also sets the 2-step cutting off the nitrous until the transbrake is release. I would NOT spray out of the hole unless I had some type of automatic activation/deactivation. I would assume you could also use a timer of some type.
David
I have a Harlan 2-step hooked up to transbrake and also the nitrous system. The 2-step is set just below the stall. It prevents the nitrous from activating. Once the T/R is pushed in, it also sets the 2-step cutting off the nitrous until the transbrake is release. I would NOT spray out of the hole unless I had some type of automatic activation/deactivation. I would assume you could also use a timer of some type.
David
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From: Lewisville, Texas
I've got a Harlan 2 step on mine. My converter stalls at 4000RPM and I have the 2 step set at 3800 RPM. I do my burn out, stage, wait until I see the 1st yellow light, hit the brake button on the steering wheel, when I see the 3rd yellow I let off the brake button and hold on. Wheels up !!!
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From: CA
[QUOTE=DERTY]Or, you wire a relay into your transbrake to activate the solenoids only when the button is not pressed. QUOTE]
this seems the way to do it correctly then . . . with out this 2-step. What is a harlan two-step anyway, first I have heard of them
this seems the way to do it correctly then . . . with out this 2-step. What is a harlan two-step anyway, first I have heard of them
Great thread. I am currently in the process of installing a TH400 with a Protorque 3800 sc. and a transbrake. was curious to how to launch the car as I have never used a transbrake or a higher then stock stall converter. mey car was previously a 6 speed. hopefully my **** dont break.