I am intrigued by the idea of using straight cut gears in a transmission because from my understanding they are more reliable/stronger/more efficient. But I know they have drawbacks too.. such as noise. And the vehicle I want to design would be street legal and very capable off road as well.

But anyway.. I am wondering if this is an option for VW power trains and what the details are on them.. how expensive, how noisy? How much more reliable? How are they shifting? are they street legal? I don't even know.. I am having trouble finding much info on them.

Straight cut (a.k.a. spur gears) in a transmission
they are more reliable? NO
they are more stronger? NO
they are more more efficient? YES
how expensive? They are less expensive to make than helical gears.

Spur gears can be really loud. Each time a gear tooth engages a tooth on the other gear, the teeth collide, and this impact makes a noise. It also increases the stress on the gear teeth.
try this web site- http://science.howstuffworks.com/gear.htm

write me if you have more questions.

I don't know if I agree with this 100%. IN MY OPINION, it is how the gears are designed. You may be thinking..."Well, Duh! A helical cut vs. a straight cut". I mean, there is more to it than "helical gears are stronger than spur gears". Material, design, PA, diametral pitch, width, etc. all account here. Many assume that spur gears a not as strong as helical gears. This is not the case. Helical gears are not AS STRESSED as spur gears. The helix, or angle at which the teeth are cut, provide for a smooth, transition or engagement between teeth. The spur gear teeth simply slam into one another for engagement. Now, back to the helical gear-this "improved transition" from tooth to tooth comes with what is called thrust. These types of gears generate thrust, which in turn, wears opposing components within the gear box. Energy is also lost when this happens (you lose your HP's here within the gear box!) Of course, this is a small amount lost, but hey, power lost is power lost! I happen to know of some racers who have been in the off road racing scene for 25+ years now. They rely on straight cut, old fashioned spur gears in their custom transmissions!

Anyway, not driving away a Mendeola-I happen to own a 2D! Thanks Mike! It has held up 100%

Fresh out of the gear box after 500 + miles of baja abuse! 800 + TRUE horsepower, 39" tires, 4500 +lb. vehicle. This spur gear came back in excellent shape-not saying a helical gear won't do the job, but I wanted to stress my point that we shouldn't underestimate this style cut when designing gears!!!

The spur gear was re-introduced to racing for a number of reasons..

The helical gear is quieter, but the wiping action as the gear turns eats horsepower, and induces axial thrust.

The wiping action also reduces tooth contact as it wipes.. making it less strong

The statement that a spur gear collides with another is actually wrong. (Think about it)

<insert picture here>

The spur gear has a wider tooth contact patch and this results in a stronger full width contact.

A real race car cares not about a little noise..

I'm just sayin'

Nope-I don't believe my statement was wrong here, maybe just a misunderstanding. The teeth on the spur gear DO make full contact with eachother on the leading or driving side of each tooth, hence a collision. Of course, an oil bath will prevent contact to a certain extent and on a microscopic level.

That's what I said.. but I suspect the term collision is perhaps incorrect.. Under load, the teeth rotate smooth as a babies butt..

Now if you gas and release the throttle, over and over, any trans will perhaps fail..

Thank you for your opinions they are equally correct and valued.