ZFG Launch Strategy

I'm seeing a trend in data logs so I want to revisit the launch strategy (not the trans brake) . All new tunes have the launch strategy update. To use it do the following

-pump the brakes
-push brake pedal all the to the floor
-go directly to 100% pedal position

It's important that you don't hesitate getting that pedal to floor, there are processes that need to happen that a driven of pedal position. If you bring it up slow or don't get to 100% on the pedal you have a higher chance of spinning.

That being said the default setting when you get my tune is going to be high, pretty much as much as the brakes will hold. Right at the 3000 rpm in first and 3500 ish in second. If you need it turned down just aks for it in a change request. Also remember those second gear launches are more consistent on crappy surfaces!

https://m.youtube.com/shorts/0Y0PL4...DdblBw5w9gh-Jlb0Rs8MUU6ktj2_NTEPjlTAoUXTDTkrc

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When you say “new” tunes have the new strategy, what start date does that mean?

Everything after April last year.

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How much to update an older tune to include the new launch strategy?

$50

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I'm not sure of today's technology by comparison but in the past, brake launching (what we used to call power braking) wreaked havoc on the converter. In fact, I had blown a front seal on the tranny. I rarely had done it so it wasn't previously abused. Are today's converters and transmissions up to the task of repeated launches in this technique?

Totally different ball game these days. As long as you don't over heat your transmission you're good to go. It's also the only way to launch.

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Ok, thanks for your thoughts on this.
In your opinion, what would it take to overheat the transmission? I would think a prolonged uphill pull with excess weight. Launching is such a short duration it wouldn't seem like that would apply.

Pulling on a hill with the converter locked is not too bad. But an unlocked converter generates lots of heat over time.


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Sorry from a laymen perspective can you explain a little more? So pump the brakes a few times and then push the brake pedal to the floor I get..but the go directly to 100% pedal position lost me. Assume that means the accelerator right? So pump brakes with left foot and then push to the floor. Then accelerator with right all the way to the floor? And that will hold the revs for launch then just let go of the brakes to go right?

I was going to start a new thread but will try here first. Seems something is not working right for me. I tried to use this feature for the first time the other night against my neighbors Durango GT and I couldn't get it to work. Either it would start to spin or if it didn't spin it would fall on it's face when I let off the brakes. I made sure the tranny was up to temp by driving to the location (about a 10-15 minute ride). We lined up the first time and I already had it in Sport (Race) Mode. I turned off the Traction Control. Pulled to the line. When he was ready I pumped the brakes three times as described and immediately pinned the accelerator to the floor. RPM's came up and it started spinning right away! I aborted that run. Second time I did the same thing and it started spinning again but we left pretty much together but he got out on me because I stumbled. I ran him down no problem but that's not what I'm getting from reading these posts and watching the videos. So I let I cool down for about 30 minutes and tried it a third time. This time I didn't hold the brakes as long and as soon as the RPM's started coming up I let off the brake and it lurched forward and then fell on it's face like I hit the brakes again! I tried it a few more time with the Traction Control on and off. I tried hitting the accelerator on the last pump of the brakes and none of it works. Also, everytime it spun the 4-WD Temporarily Disabled warning would pop up. Is it possible my tune didn't come through with this function? I got it back in August. I'm following the instructions exactly!

Send a log sounds it's just set too spicy for your traction.

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I’ll grab a couple tomorrow. We’re getting rain again today.


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Ended up getting one today. Sun came out and dried everything up. Sent it in. I made sure I had the brake pedal as far down as I could push it and the tires still broke lose. I got a code P0234 Turbocharger "A" Overcharge this time so I only grabbed the one log.

Got the tune revision and tried a launch but tires are still breaking loose! I want to make sure of one thing, when you say "pump the brakes", are you suposed to let the pedal come all the way up then press it down again three times or do you just pump it by letting it out about half way and pressing it again? Does it make any difference? I've tried it both ways and the back tires are still breaking loose! I'm guessing it's supposed to hold at specific RPM's until you release the brake pedal so you can wait for the light/flagger.

I’ve used the trans brake function several times and it works great, but obviously with a serious shock load on the entire drive train. Not good for longevity. I’ve done a few quick tries for this “loaded” brake boost launch strategy, but I couldn’t get it to work. Today I took the time to actually get it to work. It is the most awesome launch I’ve ever felt from this car! When I get another opportunity I’ll make a few runs with the dragy to get the data.

Anyway, the point of my post is to clarify the instructions a bit for anyone who hasn’t tried it, or just not getting it.

Heres the deal;
1- Must be in Sport Mode (for my setup at least), first or second gear and foot on the brake.

2- While holding the brake with enough pressure to hold the car in place, push it hard(er) 3 times quickly, don’t fully release it.

3- On that 3rd HARD pump, poke the gas to the floor and hold it there. Don’t hesitate to poke the gas, or it won’t set this great “brake boost” launch mode.

4- The revs will come up to 3k rpms (1st gear) and hold there in the “brake boosting” condition.

5- When ready, release the brake and hang on!

Note that the trans fluid temp comes right up past 200F QUICKLY, so repeated launches will super heat the fluid. It takes quite a bit of steady light cruising to get the temp back down to ~200F.

Interesting and will have to try this!
Are you getting your trans temp readings from a standalone gauge or reading the dash display? I know there's a trans temp gauge that comes up in the Tow mode but hadn't seen one in Sport mode.

Great write up! One thing to add is, turn off Traction Control.


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I use an ELM327 type device in the OBD port and view all the data on my Car Scanner Pro iPhone app. Works great for real-time data display.

Lol yeah, forgot to mention it, but turning off traction AND stability control is a given for ANY actual maximum-performance driving…