Obviously like all things it depends on hp.. Since we all are pretty much stuck with 3.88 r/p being the stoutest choice we gear it from there. Tire diameter is a big consideration as well because the height is a direct link to your final drive ratio.
3.78 2.06 1.48 1.12 is a decent street stack mild hp
At 6000rpms and a 26" tire (the most common) youd hit the traps about 106mph.
Easy on the valve train at 6000 and run a good low 12 at that mph.
3.55 2.00 1.44 1.04 this would be getting more gear to the car with bigger hp
At same rpm and tire size youd hit the traps about 115 but carrying to 6500rpms you would hit around 123.
Still not workin the motor too hard and approaching the high 10s.
Part of it is knowing how much mph/hp and rpm you can spin the engine too. Gearing is a lever to the ground IMO and the more you can gear it the better your leverage with the hp you have. That said a turbo will spool better/quicker if it works harder meaning more load so guys usually give it more gear than you would think is usable.
The 2 stacks I gave are examples of starting points to use depending on what you are shooting for with your car and the e.t. you hope to achieve. I have a few calc's that I use to set up a stack for guys when guestimating the e.t. they will get with their engine and car weight.
Nice! Thanks Jeff, that helps out quite a bit. I just keep leaning towards a turbo motor cause my car will be driven on the street as well as the freeway occasionally. Maybe I will pm ya when I decide what I am going to do exactly engine wise and I can pick your brain some more!