I have a 65 Chavy Nova which is drag race only.
It has a SBC 435hp Edelbrock EFI set up, A Ford 9 inch locker with 4.11 gears, 12x15 convo pros with M/T's pro tracs that stick like glue.
Lauch is good with no wheel spin.

I have a TH350 that has just been ovehauled with a B&M race kit and I have a Trans Brake Valve body fitted (not sure what make as I bought it Used)
Gear change is now manual but not reverse pattern as I have tested the car and click it down from neutral and it struggles to pull away then click it again is 2nd pulls away not to bad click it down again and you can feel you have hit first as the car slows like engine braking.

I have tried a few test lauches, I press the trans brake button and floor the throttle the tach rises to 3,000rpm ( 10 inch torque converter) I release the button and the car leaps forward as expected excellent.

My question is what is the best way to stage the car?
Do I move to the line and as I hit the second stage light hit the trans brake button floor the throttle and then release it as the lights change( at my track as the second car comes it to stage they hit the lights straight away)

Or do I hold some revs bring it into first stage and hold it on the trans brake button then release the button slightly to allow the car to come into stage and then launch.

I am thinking the second option would be more punishing on the transmision and generate much more heat!

I have a line lock fitted to the front brakes for burnouts and I can use it to hold the car on the line. Before I fitted the the trans brake I held the car on the line with my left foot on the brake and stalled it up to 1800 rpm as it would roll forward with any more revs.

What do you guys do?

Thanks Andy Eagle

 

You should also be using a 2 step so you can adjust the launch rpm. My converter stalls at 5700 on the transbrake but I use a 2 step to only launch at 4500 rpm. Different launch rpms can produce different results depending on track conditions.

I move into the prestage light. When we're both prestaged, I'm slightly up on the throttle. Usually 1500 to 2000 rpm and I inch into the stage light. As soon as the stage light comes on I stop, push the transbrake button and release the foot brake. As soon as both stage lights are on I go to WOT and wait for the lights to come down. Since I also use a delay box I let go of the transbrake button as soon as I see the first yellow then wait for the delay box to launch the car. Without a delay box you wait for the last yellow before releasing the button. The rpms should be up high well before you launch. Although it doesn't seem like it, it takes time to get up to launch rpm and you shouldn't be bringing the rpms up as the lights are coming down.

Yes coming up on the converter or 2 step is hard on the tranny. It builds lots of heat in the tranny oil. I run alcohol and only need a rad out of a turbo firefly but my tranny cooler is almost the same size.

Transbrake launches are hard on the driveline. You already have a 9" but you should start budgeting for 1350 series u-joints and yokes plus a good aftermarket driveshaft.

Carefull with the TH350 or TH400 transbrakes if driving on the street. Most of them only have engine braking when in first gear. This means if you're in D and let off the gas, the car will just coast like it's in neutral. Stopping distances need to be increased because the engine isn't helping slow you down. As for racing, leave it in D after you cross the finish line until you're slow enough to downshift. You shouldn't neutral a TH350 or TH400 after you cross the finish line.

You should get a bit more converter. Something that will stall in the 4500 rpm range. Stall speed isn't an exact advertised speed. It depends on how much torque is put into it. Your converter behind my engine would probably stall around 3600 rpm or higher. Using a transbrake is the only real way to know the converter's stall speed.

Hope this helps.

 

Yes thanks that does help. They use a porta tree at my local track and it has only 3 yellows as soon as you see the first yellow you nail it as the tree counts down so fast by the time your moving the green is on, I have never had a red light as the beam is 1 foot in front of the green.

Because I am a newbie to trans brakes I don't know what a 2 step is can you explain what it is and where I would wire it in?


I have a trans cooler just behind my rad and twin electric fans, one on a manual switch which I use in the stageing lanes and coming up to the line. It keeps the engine temp to around 180 F and it cools the trans too. I do have an extra temp gauge that was used for the transmission by the previous owner but I don't have a sender unit on my TH350 and I need to know where to put it on the TH350

Thanks Andy Eagle

 

A 2 step is an adjustable rev limiter. It's designed to keep the engine at a specific rpm even when you're at WOT.

 

I had a look at your web site lots of interesting tech stuff. I have run 12.76 107mph I think the trans brake should knock at least 3 to 5 tenths off that. So maybe a low twelve or a high 11 if I'm lucky. How much difference do you think it will make?

Thanks Andy Eagle

 

Actually my car only has engine braking in 3rd gear first and second do not have any engine braking. This is good if the car starts getting out of hand in the beginning of the track as the front end won't slam down when you let off. I love my reverse manual t-brake th400 on the street. Works great.

Later
Matt

 

nostang 96z.....

I know this is a terrible thing to ask, but I'm about to go from the t-56 to the th400 or th350 full manual with transbrake, and I was wondering what kind of gas mileage do you get with your setup?

<<<sitting down for this>>>

 

Well I used to get 20mpg with the 6 spd. Now I get 10mpg and that includes racing it. Not that bad...about the same as my gashog truck...lol but a lot more fun.