Drag Racing Tech - Transbrake and two step

hey guys, I just finished my swap from a M6 to the TH400. I had the two step wired into my clutch switch and it deactivated when i released the clutch. How could I get it to work with the transbrake? Any suggestions? What kind of button is everyone using for the transbrake?

hey guys, I just finished my swap from a M6 to the TH400. I had the two step wired into my clutch switch and it deactivated when i released the clutch. How could I get it to work with the transbrake? Any suggestions? What kind of button is everyone using for the transbrake?

I don't know the answer to your question and forgive me for the question i'm about to ask. Something i've always wondered, why would you want a two step with a transbreak? I can understand if you have a turbo and are looking for instant spool but why would any other combination need a two step when using an auto with a break? Thanks.

I use one of those big red trans brake buttons. :) 12 volts to the transbrake button. Then Y off to the trans brake and 2 step with a relay activating the 2 step. I believe its the white and grey wires that negativly activate the 2 step. Just run those thru a relay that is activated by the transbrake button. Thats the way I remember it. It's been awhile. I now have an aftermarket EFI with the 2 step built in.

I bracket race with an NA motor and I use my 2 step for consistancy. I can set the launch rpm and when the lights start to come down I mash the pedal to the floor. I don't need to watch the tach to keep a constant rpm. Besides that its a blast :drive:

i run a digital-6, i just run 12v to the switch and then spliced from the switch to the digital-6 2 step and the trans brake. i also have the nitrous system wired into the system so when on the trans brake and 2 step, the nitrous systems shuts down so i know for a fact that the nitrous system won't come on at the line on the brake or 2 step. just a little insurence and is vary easy to wire. let me know if you want the diagram. set-up like this is vary good for breaking parts because it hits HARD! :burn:

I use one of those big red trans brake buttons. :) 12 volts to the transbrake button. Then Y off to the trans brake and 2 step with a relay activating the 2 step. I believe its the white and grey wires that negativly activate the 2 step. Just run those thru a relay that is activated by the transbrake button. Thats the way I remember it. It's been awhile. I now have an aftermarket EFI with the 2 step built in.

I bracket race with an NA motor and I use my 2 step for consistancy. I can set the launch rpm and when the lights start to come down I mash the pedal to the floor. I don't need to watch the tach to keep a constant rpm. Besides that its a blast :drive:

That is a good idea. Do you hold the transbrake in your hand or have it mounted somewhere?

i run a digital-6, i just run 12v to the switch and then spliced from the switch to the digital-6 2 step and the trans brake. i also have the nitrous system wired into the system so when on the trans brake and 2 step, the nitrous systems shuts down so i know for a fact that the nitrous system won't come on at the line on the brake or 2 step. just a little insurence and is vary easy to wire. let me know if you want the diagram. set-up like this is vary good for breaking parts because it hits HARD! :burn:

It sounds good, but I don't think you can run the digital-6 on the LS1 with individual coils. Correct me if I am wrong.

I don't know the answer to your question and forgive me for the question i'm about to ask. Something i've always wondered, why would you want a two step with a transbreak? I can understand if you have a turbo and are looking for instant spool but why would any other combination need a two step when using an auto with a break? Thanks.


Like stated below, I do not want to have to watch the tach to get my RPMs in the right place.

OK, i'm new to this automatic game so i'm learning here. I'm waiting on my stuff but one of those items is a th400 with a break (used to have a six speed). I was under the impression that you just hit the button for the break, floor it and then your motor goes up to whatever rpm your true stall point is of your converter, and then you hit the button once again and it takes off. Is that not the case?

OK, i'm new to this automatic game so i'm learning here. I'm waiting on my stuff but one of those items is a th400 with a break (used to have a six speed). I was under the impression that you just hit the button for the break, floor it and then your motor goes up to whatever rpm your true stall point is of your converter, and then you hit the button once again and it takes off. Is that not the case?

you need to hold the button, then when released, the brake is also release. the button needs to be a momentary switch. you could use an on/off but you may run into delay problems. also keep this in mind, every second that you are on the trans break, the trans temp goes up 50 degrees, give or take a few degrees, do the math.

It sounds good, but I don't think you can run the digital-6 on the LS1 with individual coils. Correct me if I am wrong.

sorry, you can't, i still run an LT1, and yes, i hold the button with my right hand while holding the shifter, then it is dropped out of the way when released. also don't not use a shifter handle with the button on it, it would be really bad if that button was hit during a run

OK, i'm new to this automatic game so i'm learning here. I'm waiting on my stuff but one of those items is a th400 with a break (used to have a six speed). I was under the impression that you just hit the button for the break, floor it and then your motor goes up to whatever rpm your true stall point is of your converter, and then you hit the button once again and it takes off. Is that not the case?


I have heard the same thing however a 2-step has got to be be better for the trans/converter. Instaed of using the 2-step to limit engine Rpm you are using the converter/trans....that's can't be good.

I have heard the same thing however a 2-step has got to be be better for the trans/converter. Instaed of using the 2-step to limit engine Rpm you are using the converter/trans....that's can't be good.

vary true, the 2 step cuts power but is still putting a load on the converter, none the less, it is slightly easier on the trans with the 2 step.

OK, thanks a bunch guys, that's just the information I was looking for:)

I have heard the same thing however a 2-step has got to be be better for the trans/converter. Instaed of using the 2-step to limit engine Rpm you are using the converter/trans....that's can't be good.

What's not good about it? The fluid coupling locks up the converter at stall speed. The trans still builds heat regardless of the two step because you're still pumping fluid through converter. You're just not stalling it up on the brake. The trans still locks first and reverse together. The only reason on a NA or N2O setup to need a transbrake with a two step is simply to control launch RPM below stall speed. Besides that, just hold the button down and release when you are ready to go.

I will be wiring my Harlan 2Step in with the TB and N2O, for the reasons stated above. I can dial the launch rpm in, have the foot to the floor and nitrous armed waiting for the buttons release, then BAM off I'll go. I havent even wired up the H2S or Harlan Shift Light either, but realize the few runs I have made with the combo, I need too. Cant wait. Any diagrams for this combo, H2S, HSL, TB and N2O? Thanks

What's not good about it? The fluid coupling locks up the converter at stall speed. The trans still builds heat regardless of the two step because you're still pumping fluid through converter. You're just not stalling it up on the brake. The trans still locks first and reverse together. The only reason on a NA or N2O setup to need a transbrake with a two step is simply to control launch RPM below stall speed. Besides that, just hold the button down and release when you are ready to go.

I guess I forgot to mention this is for my 408 w/F1 Procharger

So, your stall speed will increase as boost goes up. That will continue until the torque increase tops out. Then hold on. We only used the two step on Kevin's car to build boost faster (advantage of it on a turbo application). Otherwise, you may find that it works the best straight off the brake if your converter works good.

Can't a rev limiter perform the same task as the two step on a nitrous-n\a car?

SuperC1, you asking about in the tune? If so, then not in an Auto. E.g. my rev limiter is at 7400rpms, my stall is 4,000rpms. If I hold the tranbrake, and floor the gas, the engine revs up to the stall speed, laying on the converter which generates more heat in the trans. But it wont rev to 7400rpm. When I launch it will shoot up to whatever rpm I shift I at. Besides you can dial your converter in as well, by launching at different rpms for different track conditions etc..Many converters like a small flash rpm, say 500, so I would set the H2Step for 3500 or so. Then brake, floor it, stutter and go.

SuperC1, you asking about in the tune? If so, then not in an Auto. E.g. my rev limiter is at 7400rpms, my stall is 4,000rpms. If I hold the tranbrake, and floor the gas, the engine revs up to the stall speed, laying on the converter which generates more heat in the trans. But it wont rev to 7400rpm. When I launch it will shoot up to whatever rpm I shift I at. Besides you can dial your converter in as well, by launching at different rpms for different track conditions etc..Many converters like a small flash rpm, say 500, so I would set the H2Step for 3500 or so. Then brake, floor it, stutter and go.

No, I'm not talking about the one in the ecu. I'm talking about adding a seperate rev limiter to launch with. In turn what I'm saying is if the h2step is in a since a rev limiter why couldn't you just add a second rev limiter on a momentary switch and have it do the same job as the 2step?

No, I'm not talking about the one in the ecu. I'm talking about adding a seperate rev limiter to launch with. In turn what I'm saying is if the h2step is in a since a rev limiter why couldn't you just add a second rev limiter on a momentary switch and have it do the same job as the 2step?

You could if the 2nd rev limiter only worked on the button somehow. The 2step is essentially 2 rev limiters. One works with the TB activated, one works for down track running or burnout.

I agree with the idea of using a 2step to control the launch rpms. Some conditions will warrant a harder launch than others, so the ability to dial your launch rpm down for less traction would be nice. Otherwise your gonna launch at true stall no matter what.

Derty- for us boosted guys, your saying that a 4000stall will not stop at 4000 unless our tq happens to peak right there? Or in other words the boost will in effect cause the stall speed to be higher? :eek2: If thats the case, I definitely want a 2step.

here.
http://i17.photobucket.com/albums/b67/68maro/complete_basic_wiring.jpg

Derty- for us boosted guys, your saying that a 4000stall will not stop at 4000 unless our tq happens to peak right there? Or in other words the boost will in effect cause the stall speed to be higher? :eek2: If thats the case, I definitely want a 2step.

Yes. Horsepower is a function of torque. As boost increases torque increases until you either stop the boost from increasing (which is what we do in conjunction with a two step). As the engine torque keeps going up the stall speed will change. It's not going to rocket to infinity, but you are going to see that on a 4000 stall converter that it will continue to climb. Eventually it will plateau.

The addition of a two step to a turbo car does some additional magic that helps the boost come up a little faster by creating a detonation scenario in the exhaust. That detonation increases exhaust pressure forcing the turbine speed to increase.

There are a few people using transmissions with the Easy Stage option from Rossler. In that case Easy Stage locks the oil in the converter preventing new oil from going in and lowers the line pressure effectively. By lowering the line pressure they're allowing the stall speed of the converter to come up much faster. I'm not a fan of that approach not because it helps the stall come up faster but because that oil trapped in the converter is getting real hot and is not being replaced. So, as soon as the trans button is let go that super hot oil goes right down your trans, through all the clutches, etc. and into the pan where nothing but significantly colder oil awaits it. If your trans holds up that's fine, but when it fails your super fucked.

Derty-
That explains is well enough. Being that my car is supercharged instead of turbo, the scenario would be slightly different in that I will not need something to limit boost. The 2step will do that by controlling rpm's.
Thanks for the explanation, Im going to pick up my TH400 today and will be stopping by the speed shop to get a 2step box while Im out.