When I was racing, ( Long Long ago, in a galaxy far far away ), I had a stand alone Accelerometer for doing street testing
when not at the track. It gave most of the information that one looks for, zero to 30, 60, 100, 1/8 mile, 1/4 mile, Launch G Force,
braking, etc. The company was G Tech Pro, and, it was between $100 and $200. I just looked, and, they are still in business.
The meters now start at $199. Back then, if I ran it at the track, and, compared it to the time slip, it was fairly consistent.
I can't imagine that they have gotten any less so over the years. Here is their site, in case anyone is interested. It does
require a 12 Volt power source.
http://www.gtechpro.com/index.htmlOtherwise, most cities have a drag strip nearby and they have test and tune nights, Midnight Madness, etc. for $50 or less.
Phone apps are cheap to free, but, not as accurate.
Speed costs money, How fast can you afford to go.