Ok, totally dump question. Does a higher turn motor equal more speed assuming the gearing is the same? Example would a 20 turn motor be faster than a 17 turn in the same geared car or the other way around? Or, something different altogether?

If you replace a 20 turn with a 17 turn with no other changes the 17 turn will be faster than the 20 turn... But a 17 turn will draw more amps and will use the battery faster...

Lower the turn ,faster the motor... The system would require a capable ESC and would probably need to be readjusted in gear ratio...

Generally manufactures overrate ESC's motor turn cabability for warranty purposes ...

For example , The evader st esc is rated for 20 turns and above (540 motor's) , But it is cabable of handling a 17 turn motor when using proper gearing ...

When we use the 17 turn motor and proper gearing the 17 turn is faster and stronger and more top end as compared to the 20 turn motor...We gain our battery time back by proper gearing...

Without explaining the relationship of turn and winds, try reading the article on Associated's website entitled Selecting your Next RC Motor.
The example you mentioned comparing a 20 and 17 turn may be of little difference in speed if they are the kit supplied type motors, which aren't built to the quality as some motors made for racing. You may see some stock motors that are faster than these.

A good quality 27 turn stock race motor will be faster than a 20 turn motor that will come with RTR kits due to the technology inside the motor...

But when 2 motors of the same quality (brand, series and winds) the lower turn motor will probably be faster...