BMW 320 with straight cut gears flies through the pack

[RidgeBack]

http://www.youtube.com/watch?v=dmJH84FnQa8&NR=1

Great vid!

[Kuane]

my ears hurt from that....

[RidgeBack]

my ears hurt from that....

Yeah the gears are loud....



WARNING - it is LOUD!

[Variance]

That video always makes me sad that the S42 is a race-only engine...

[haxmire]

Old but still very good.

[parabellum]

OH god.

Wow...just wow....I have never heard straight cut gears before....holy shit.

[Nik1703]

Seen this one a long time ago, great video. What the hell is that racket whining noise?

[RidgeBack]

Seen this one a long time ago, great video. What the hell is that racket whining noise?

Seriously? :shifty

Straight cut gears.

[Le Nitro]

saw this a few years back...what exactly is a straight cut gear? Damn that is ear piercing. With my 5.1 surround it makes u wanna kill urself.

[n2bimmer]

yup seen that one. Sick.

watch this

http://www.youtube.com/watch?v=P-WVM8wfuoM&feature=PlayList&p=E663F8E21865C243&playnext=1&playnext_from=PL&index=34

[triggrhaapi]

Seen this one a long time ago, great video. What the hell is that racket whining noise?

That would be the glorious noise of straight cut gears.

[Drexial]

Seen this one a long time ago, great video. What the hell is that racket whining noise?

Sarcasm?

hmm not detected.

It's the straight cut gears in the transmission. It's the gears making contact with each other in high speed. Normal street transmissions are helical cut, which has sort of a curve to the gear to ease in contract instead of making flat contact with the gears.

Sort of like rolling your palms together instead of clapping them together.

[RidgeBack]

yup seen that one. Sick.

watch this

http://www.youtube.com/watch?v=P-WVM8wfuoM&feature=PlayList&p=E663F8E21865C243&playnext=1&playnext_from=PL&index=34

Great vid - thanks. That B6 has some serious top speed going for it. Just flew by the one porsche.

[yeomgon]

saw this a few years back...what exactly is a straight cut gear? Damn that is ear piercing. With my 5.1 surround it makes u wanna kill urself.


in short, helical gears operate quieter than straight cut. Straight cut will 'whine' the faster they go but offer both a. More directional application of force allowing for less power loss. And b. Higher acceptable loads until failure. Basically making the transmission stronger and more efficient. However though, like noted before, car manufacturers don't use straight cut due to the imense noise the transmission will produce.
there.

[Le Nitro]

Can't they load up on sound deadening material around the transmission tunnel to reduce the noise?

[NMMR]

was that taken with a cell phone?? its like 3 frames per second!

[n2bimmer]

More from the Nurburgring


Thought you guys would like to see.
http://www.youtube.com/watch?v=bkAEdYTh6WM
some more. http://www.youtube.com/watch?v=Qoxx0vhZlaM
http://www.youtube.com/watch?v=Sm3aJ27L1i8
http://www.youtube.com/watch?v=xkpwB_dYZ5U
http://www.youtube.com/watch?v=tyjgPKEMIa8
http://www.youtube.com/watch?v=qUdqhDNfoxE


http://www.youtube.com/watch?v=VBNmbF-7HPE
http://www.youtube.com/watch?v=ZR93agTAGgg

[Nik1703]

Sarcasm?

hmm not detected.

It's the straight cut gears in the transmission. It's the gears making contact with each other in high speed. Normal street transmissions are helical cut, which has sort of a curve to the gear to ease in contract instead of making flat contact with the gears.

Sort of like rolling your palms together instead of clapping them together.

ah i see. i think i will pass on that setup, lol.

[RidgeBack]

saw this a few years back...what exactly is a straight cut gear? Damn that is ear piercing. With my 5.1 surround it makes u wanna kill urself.

Top is helical cut (normal passenger cars etc)

Bottom is Straight cut for race cars etc

http://i20.photobucket.com/albums/b226/oosa_hagar/Cars/straightVShelical.jpg

[artifact]

Can't they load up on sound deadening material around the transmission tunnel to reduce the noise?

Why?? It's a race car.

[T-Rex]

S42 + Sequential Straight cut gearbox....DO WANT

[HE53]

Awesome video.. I've got a better full version of that on my computer at home.

[e36m3speed]

Why?? It's a race car.

I think he meant he wanted to see them on street applications with the use of sound deadening material... hmmmmm

[RidgeBack]

I think he meant he wanted to see them on street applications with the use of sound deadening material... hmmmmm

Would need to be a literal tonne of sound proofing for it to be daily drivable for the public.

[Jam Boy]

Think of straight cut gears as the reverse gear in most Hondas...

[sleeve]

here a bit of pictorial help

straight or some times called dog cut, a whole gear box full is called a "Dog box"
http://www.zsiguli.hu/images/cikk286_tolokerekesvalto.jpg

helical
http://i51.photobucket.com/albums/f362/dschybrid/Product%20Pictures/Untitled-3.jpg?t=1246573674

The helical are what you have in your street car, because of the noise reduction and its easier to change gears with out having to be dead on. But there is a draw back that there is about a 10% sacrifice in performance from the straight cut, in both frictional losses and strength, straight cuts are much stronger as well.

[funfgang]

ya, thats still abnormally loud...the gears in the 997 cup i was in last year and 996 cup from a year ago werent NEARLY that loud...but it IS a GLLLORIOUS noise...best part of the experience because the noise continues to increase rather than go down and climb back up...love it.

[mike87]

old as shiz but still good

[upd]

So what kind of performance gains would you get with straight-cut vs. helical?

[sleeve]

^^^^^^^^^^^^^^^^^^^^^^^^

Not really enough to make it worth the time or money unless you have way too much HP already and are eating gearing, or you are after that last little bit of performance in you race car.

[prodjsxb]

December 28, 2006

Awesome Clip... but ff you find any more from dates like that, don't post them. Seriously BFC has seen them all!

[Walki600]

here a bit of pictorial help

straight or some times called dog cut, a whole gear box full is called a "Dog box"
http://www.zsiguli.hu/images/cikk286_tolokerekesvalto.jpg


No.

"Dog" refers to the type of engagement. You can have a straight or helical cut dog box.

[DuWerk]

S42 + Sequential Straight cut gearbox....DO WANT

plus a supercharger and I'm set, would daily drive it, and be annoying as hell

[sleeve]

No.

"Dog" refers to the type of engagement. You can have a straight or helical cut dog box.


Thanks for the heads up, I was always lead to believe that a straight cut gear box = dog box but after a bit of digging I find you are correct.