Need some insight about helical vs straight cut gears question.

Race cars use straight cuts while most production car use helical.
science behind this: helical gears have more allowable stress due to larger contact area thus it is strong but axial loads are present, making the gear prone to axial displacement.
on the other hand the straight-cut gears have less contact area for stress thus it is less strong but no axial load is present.

however, if you have a lot of torque, the helical gear will start to experience greater axial load, the case may fail and then you'll need a bulletproof transmission case and stronger shafts holding the gears.

Full straight-cut gears will cost around $5k-6k for let's say, an s2k
bulletproof transmission case: i don't really know.

CMIIW at any part.

Would you go for full straight cut gears or upgrade your transmission case and shafts ??? (cost-wise)
you'll get that fancy/annoying whining sound if you choose straight cut gears..

 

I thought straight-cut teeth delivers more power than helical. But, noisier and wear faster.

 

I may be wrong, can someone explain how the gear mechanic works?

 

short term stress (street) - either approach probably works.

long term stress (race) - constant axial loading probably trashes bearings sooner. so failure mode shifts, but things still break.

only spur gears can work in both scenarios. maybe that's why?