The slip
1/4 ET and 1/4 MPH are the two that matter — together they tell traction apart from power.
The run
What is it doing?
This is a structured diagnostic interview, not a chatbot. It uses your car's details and any codes you enter, then asks whichever question best separates the likely causes.
Considering
Your setup
The car
Last dyno figure
From the Virtual Dyno in your P1 portal. Without it, trap speed can't be checked against what the car actually makes.
What stays on the desktop
The Virtual Dyno and datalog analysis run in your P1 portal on a computer. Those chew through logs with hundreds of thousands of rows, which is a laptop job, not a phone one. This app is for the things you do standing next to the car.
Send to P1
Everything you've entered stays on this phone. Nothing is uploaded anywhere. To send it, copy the block below into a text or an email to the shop.
Press Build it.
Saved runs
No runs saved yet. Analyse a pass on the Strip screen and press Save this run.
Add to your home screen
In Safari, tap the Share button, then Add to Home Screen. It opens full screen like an app and works with no signal — useful, because most tracks have none.