mavtais

iTrader: (12)

Companies like OS Giken and Spoon make "cross gear sets"
What does that mean? They use it separately from something like a close-ratio gear set. Is this a type of gear design or what? And I only notice the Japanese & UK mention the term, but what is the difference?
http://www.justjap.com/parts_ngearbox.htm
http://www.modacar.com/products/Honda/Civic/GEARSET/
http://www.greenline.jp/catalogue/bt...pe=Gear%20Sets

edit: Oh $H!+ I just noticed this was posted in FI.

i8acobra

iTrader: (6)

They're not really "cross gear sets", they're "cross-cut gear sets" or "straight-cut gear sets". Basically, it's means the gears are not helical. Straight-cut gears have their teeth parallel to the rotating axis. Helical-cut gears have their teeth at an angle to the rotating axis. Straight-cut gears are usually stronger, but noisier that helical-cut gears. Most racing gearboxes use straight-cut gears. Most OEM boxes use helical-cut gears. Also, most straight-cut gear sets use "dog" style engagement, while helical sets usually use synchros.

mavtais

iTrader: (12)

So, does the Z come with cross gears? They look like they are kind of helical, but really just cut diagonally. I know it comes with synchros (I know what those are). Here's a picture courtesy of BriGuyMax from his thread titled "Professional analysis and pictures of our 6MT internals"
https://my350z.com/forum/forced-induction/246117-professional-analysis-and-pictures-of-our-6mt-internals.html

sentry65

iTrader: (11)

yes, all street cars come with cross cut angled gears

usually only race cars or highly modified cars use straight cut gears

Netko350Z

iTrader: (8)

I believe the reverse gears are straight cut

Vash350Z

iTrader: (9)

An advantage to straight cut is that you can beat the holy hell out of them and they will last for a long time, power-shifting, etc. The main disadvantage is that shifting always requires rev-matching, also they are very loud.

simonfencer

Yes, they are very loud...and manufacturers spend huge piles of money on ways to make gearboxes quiet, I doubt they would want to spend even more money.

Now, one place where the might start to show up in the future is in computer controled manual gearboxes, where other than the user pulling a paddle they don't have any control over the actual shift.

sentry65

iTrader: (11)

no you can have straight cut gears with syncros

only a dog box with straight cut gears require exact rev matching