16 replies to this topic

[Tout]

A little bored this morning so I was hopping sites, noticed the LX guy's leaning toward trans brakes, I personally don't see the need or want to deal with the heat issues in the trans. What do you guy's think?
Tout

[Williams RT]

They are great for launching a car hard. If you have the power, suspension and tires to handel it I would do it in a heartbeat.

[Jay6spdRT]

Tout's definitely got the power. Tout, ask Mike or John about them. Not sure if they run em or not. IF the car would make better times with one, those guys would definitely have them, that I guarantee you.

[ScapeGoat]

I would use one if I switch out trans. The NAG1 trans brake has issues. Its not a true trans brake. A real trans brake holds first and reverse at the same time until release. You cant reverse the carrier in the NAG1 to do this. But trans brakes are for Centris, Turbos, and Nitrous cars so you can launch into your powerband. Touts car with a 440 and KB makes its power down low. It would just break parts or traction.

[Tout]

I think John had one and tossed it when he had the trans rebuilt.
Tout

[Williams RT]

It would be a lot better with a stutter box if you use one. I did not know they even made one for these transmissions?

[ScapeGoat]

Johns never worked right. To make it work you have to use an MSD rev limiter to set your launch RPM. Problem was it would also kill the timing all the time. Could have been installation error (not John) or something else. All I know is it killed the car on the dyno. He lost over 100hp until it was disconnected.

[Tout]

I think Jim's car has one in the TH400.

[ScapeGoat]

I think they did, but I doubt he will need it.

[Tout]

Johns never worked right. To make it work you have to use an MSD rev limiter to set your launch RPM. Problem was it would also kill the timing all the time. Could have been installation error (not John) or something else. All I know is it killed the car on the dyno. He lost over 100hp until it was disconnected.

Mike
They also talk about a two stage rev limiter in this conversation

[NO COMPROMISE]

I do have a trans brake but is not being used. Tim thought with all the torque we would just start breaking stuff. I agree a turbo or nitrous car would be a better application.

[lakersfan7272]

Jim how's the car coming along?

[ScapeGoat]

I do have a trans brake but is not being used. Tim thought with all the torque we would just start breaking stuff. I agree a turbo or nitrous car would be a better application.

Tim and I are agreeing way too much lately! Something has to give

looks like good weather up in Chi town today, maybe we will see some news out of Jim & Johns cars today

[iron6]

I do have a trans brake but is not being used. Tim thought with all the torque we would just start breaking stuff. I agree a turbo or nitrous car would be a better application.

Tranz brakes are cool and help with reaction times, launch and costly. My experience with a NA 472 stroker with a 727 trans and Turbo-Action valvebody with the tranz brake and also a 5400 RPM Turbo action converter. The MSD is connected to a two step that plugs to the valvebody that causes a solenoid to lock the tran between first and reverse. A two step can have a selector that allows you to select launch rpm usually between 2000-5800 rpm or plug a two prong chip into the MSD for desired launch. Once you're staged hold the brake and push the button for the tranz brake let off the brake. Push the gas peddle to the floor and the car will rev to the desired RPM. The MSD will kick spark in and out to the desire launch rpm. Sometimes it will distract the other driver. Car sounds like it may blow. When you let the button go hold on because you'll come out of the hole like a rocket. Strongly recommend a neck brace. It is a violent launch and you may brake your weakest part. The key is to shock the suspension and tires into hooking. I launched my 472 at 5000 rpm. 60 ft was 1.47 to 1.50 What’s nice is your reaction time get better with practice. I hope this helps. I'm not sure how this would work on our computer driven cars or NAG1. GSO probably knows that answer.
Iron6

[Tout]

Tim and I are agreeing way too much lately! Something has to give

looks like good weather up in Chi town today, maybe we will see some news out of Jim & Johns cars today

Going to be hot and windy, but we should see something, hope they get a few passes in before the afternoon rain showers, pretty chilly in Philly this morning and it's a very light misty fog/rain here.
Tout

[NO COMPROMISE]

Iron6 gives a good description. At drag school we were launching at 3600 RPM and putting down 1.2X 60 foot times. Great FUN! Will be great if they get in some track time up in Illinois today.

[ScapeGoat]

Here are the problems

1. Our trans are computer controlled. This isnt a 727 or 400. The TCM is very tricky. Hence the reason you cant modify it while tuning. And the ECU doesnt seem to like the MSD rev limiters. But it can be done, just takes time and patience to make it work. So its not just buying a valve body and you are done. We arent dealing with 70s model trans. And I will double check this, but I think it is impossible with the NAG to hold 1st gear and reverse at the same time.

2. 1000+ lbs! Its not the same. You cant talk about what you can do with an old model car. Shocking a drivetrain at 3200lbs compared to 4200+ lbs is nothing alike

3. Tire sizes. Now you can covert to 15" rims and use the sidewalls to absorb the shock but 17" tires dont give you the give. So you will either grab and break parts or break traction

And Ive pulled a 1.46 60 leaving at just 1500rpm