PerfExpert vs JB4 PRO

Know your car's true performance. Turn your smartphone into a professional dyno. Measure the real horsepower and torque of your engine — within 2% of a chassis dynamometer — and time your car's acceleration. No OBD adapter, no cables, no expensive dyno sessions. Just mount your phone, accelerate, and get instant results. Test and compare performance upgrades. Whether you're verifying an ECU remap, testing a new exhaust, or tracking the effect of a chiptuning session, PerfExpert gives you objective, independent data you can trust. HOW IT WORKS 1. Create your car profile Enter your vehicle's weight, tire sizes, and gear ratios. Not sure about a spec? The app guides you through every step. 2. Mount your phone & accelerate Secure your phone in the car — no connection needed. Find a flat, straight road. Accelerate in one gear from low RPM to redline. That's it. 3. Get instant results Power and torque curves appear immediately, just like on a real chassis dynamometer. Compare runs, track your modifications, and share results. MEASUREMENT MODES Dyno — Full power & torque curves vs. engine RPM. Advanced drivetrain loss model, rev limiter detection, and correction standards (DIN, SAE, JIS, CEE, ISO). Results as detailed as a professional chassis dyno. Timed Run — Measure acceleration from a standing start. Speed intervals: 0-100, 100-200, 80-180, 60-160 km/h — 0-60, 60-120, 50-110, 40-100 mph. Distance: quarter mile, eighth mile (with trap speed), 60 ft. Max speed and peak acceleration on every run. KEY FEATURES - 2% accuracy compared to professional chassis dynamometers - No OBD adapter or connection to your car required - Works with your phone's built-in sensors - External GPS available as an in-app purchase for pro-level precision with a compatible device (RaceBox Mini, Mini S, Micro): rolling start dyno, free phone mounting - Power correction norms: DIN, SAE, JIS, CEE, ISO — using real-time atmospheric pressure, temperature, and humidity - Interactive charts: pinch to zoom, tap for exact values - Export results as PNG image or shareable web link - Custom units: HP, CV, kW for power — Nm, ft-lb, mkg for torque — km/h, mph for speed - Works on phones and tablets PERFEXPERT PRO (optional subscription) - Custom logo on your results - Cloud backup of your results - CSV data export WHO USES PERFEXPERT? - Car enthusiasts who want to know their real HP and torque - Tuners and mechanics verifying ECU remaps, chiptuning, intake, exhaust, or turbo upgrades - Owners comparing before/after results of any modification - Drivers timing their 0-60 mph or 0-100 km/h acceleration - Anyone curious about their car's true performance IMPORTANT NOTES - Dyno mode requires a manual gearbox or an automatic with manual/sequential mode - For best results, use a flat, straight, horizontal road with no traffic - External GPS (in-app purchase) unlocks additional features with a compatible device (RaceBox Mini, Mini S, Micro): more reliable results, rolling start dyno (no need to stop before measuring), and free phone orientation Sample dyno and acceleration reports: https://app.perfexpert-app.com/results/featured FAQ and support: https://www.perfexpert-app.com/faq Join the PerfExpert community: https://www.facebook.com/groups/perfexpert/ Privacy Policy: https://www.perfexpert-app.com/privacy-policy Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

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.