I'll chime in.
"Chips" were/are usually for turbo or supercharged cars; and they used to be chips, actually a daughterboard with a chip on top that modified all sorts of things in your cars engine management. In my old VW for example, it would reprogram spark timing, ignition, boost, etc and squeeze more out of the vehicle. Chips haven't been common for a while, companies such as APR and GIAC have been using empty memory space on the Motronic to write their software, but people still call them chips. My ecu had an APR reflash and it was amazing. Couple it with some other mods and it really kicked! Check out
www.vwvortex.com forums and APR and GIAC for a bit of info.
Let's go to a NA (naturally aspirated) vehicle and a chip or reprogram of engine variables isn't going to get you much. VW folks that "chipped" with non turbo engines used to see maybe 8-12HP and any gains that minimal you need to look at the power curve and see if you're gaining HP by moving the curve up and losing any torque. In small engines (4 cyl) such as ours losing torque is bad
Hence why I tend to laugh at the Honduh boys that put these fartcan exhausts on and lose backpressure which they need to produce what little torque they had in the first place with their little engines. In a turbo or supercharged vehicle you do want to get heat away from the engine quickly (avoid heatsoak) and even then you don't want to do a test pipe and dump it all openly unless your engine has a lot of torque and you can afford to lose some for high rpm range hp.
I'll stop rambling now... hope this helped in some way.