Telemetry for Dummies

So I'm currently in the process of building a Factory Five Roadster with the plan being that it will be making regular trips to the track once done. I figured with the car in a million pieces now was the perfect time to try to set a good foundation for future telemetry capabilities - and there lies my problem as I have no idea where to start.

For reference, I'm currently using my phone (Harry's lap timer) and the results have been - spotty - to say the least.

So moving forward I have a few issues - the engine is a carbureted 427W so there is really nothing "smart" on the car to begin with for data collection. Ideally I suspect I'd get a system that can improve the GPS capabilities of my phone initially but be open to expansion so I can add sensors to track throttle / RPM / Brake / Speed / etc.

Any suggestions of any products I should be looking into?

The most reasonably priced off the shelf stuff is the AutoSport Labs Race Capture stuff.

The only reason I didn't go with that is it requires a cell connection to do any live telemetry back to the pits.

Appreciate the link! I'll have to dig into this a bit to see what I can make of it. Live telemetry won't be an issue for me (at least not at this point) so that shouldn't be too much of a problem.