JB4 PRO vs Dragline

Smart phone integration for your JB4 performance tuner to change maps, monitor live engine data, record logs, manage fault codes, update JB4 firmware, and much more! Note the JB4 PRO free app requires the JB4 PRO BT adapter and is not compatible with the JB4 Mobile BT adapter.

Dragline is a precision drag racing timer for iPhone and Apple CarPlay – built for drivers who want real performance data without the bulk of dedicated hardware. Arm the app, launch your car, and Dragline automatically detects your run and times every segment with GPS-blended accuracy. No buttons to press mid-run, no setup required. TIMING Measure 0-30, 30-60, 60-120, and quarter-mile times with high precision. Automatic launch detection starts the timer the moment your car moves – delivering consistent, repeatable results run after run. GPS speed blending and accelerometer fusion give you results comparable to dedicated timing devices. Enable Top Speed tracking to capture your peak speed on every run. TOP SPEED Track your highest speed hit during any session. Top Speed is recorded alongside your segment times, displayed on your profile, and has its own All Time and This Week leaderboard so you can compete on every metric that matters. RACE MODE Challenge your crew to a real-time roll race – no cones, no spotter, no guesswork. Create a room, share a 4-digit code, and get up to 4 drivers synced and ready. Set your start and finish speeds, hold your speed in the window, and the countdown fires automatically when everyone's locked in. Synchronized start across all devices. Results are instant. LEADERBOARD Compete globally on both All Time and This Week leaderboards. Post your best times for each segment individually – your 0-30, 30-60, 60-120, quarter-mile, and top speed are ranked separately so every metric counts. Weekly leaderboards reset every Sunday, giving every driver a fresh shot at the top. Filter by car to see how your specific build stacks up against similar vehicles worldwide. PERSONAL BESTS Your Recap tab tracks your all time and this week bests for every segment. See exactly where you stand, what's already been posted to the leaderboard, and which times are ready to submit. All Time and This Week bests are displayed side by side, so you always have the full picture at a glance. GARAGE Browse builds from drivers around the world. See their car specs, modifications, photos, and best 0-60 times. Post your own build with photos and a full mod list, like and comment on other builds, and show the community what you're working with. The Garage is where performance meets culture. SHARE YOUR RUNS Every run you record can be shared as a professionally styled stats card – showing your segment times, car info, and run date in a clean, minimal layout. Choose exactly which runs to share and send them anywhere – Instagram stories, iMessage, Twitter, or any platform you use to show off your build. Whether it's a personal best or just a clean pull, your results look the way they deserve to. RUN HISTORY Every session is automatically saved with your car details and a timestamp, building a complete log of your performance over time. Scroll back through every run, track your improvement, and always know your best. APPLE CARPLAY Full CarPlay support means your times are displayed right on your dash – no need to glance at your phone mid-session. Stay focused on the road while Dragline handles the data. DRIVER PROFILE Set up your driver name and car info once and it follows you everywhere in the app. Your username and vehicle appear on every leaderboard entry so other drivers know exactly who they're racing against. Challenge friends directly from your profile by sharing your best times and inviting them to beat you. BUILT FOR PERFORMANCE Dragline is designed for drivers who take their builds seriously. Whether you're chasing a personal best, competing on the weekly leaderboard, showing off your build in the Garage, documenting a clean run to share with your crew, or lining up against your friends in Race Mode – Dragline gives you the tools to do it right. Dragline is designed for closed courses, racetracks, and private roads only. Always follow local laws and never use timing features on public roads.