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shay2nak
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Discussion Starter #1
what is that high frequency whining noise you hear with race cars? Especially the closed top ones. For example, M3 GTR. Also you can hear it in that video with the motorsport exige vs. c5 corvette.

And if you've ever played Gran Tourismo 3 with a fully modded car or race car.

Thanks!
Ara
 

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insert clever title here
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It's due to the design of the gears in the tranny. I'm not sure if it's the gear profile itself, or rather the angle of the teeth - straight cut on a race car, angled on a passenger car. The result is much more transmission noise.
 

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shay2nak
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Discussion Starter #3
oh, ok. because it seems as the driver goes up in gear, there is a slight increase in the frequency of the noise.

So the only way a stock car, Elise for example, can reproduce this noise is to have a different type of transmission?
 

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lol, side note: if your transmission is going out they also sometimes make that same noise with each gear.
 

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Since noise isn't a big issue in race cars most gear boxes have straight gears (most gearboxes on the street have helixical). Listen to the gear whine in an in-car shot from a NASCAR race.

Straight gears are considered stronger. I think they are easier to shift (best without the clutch - who needs syncros!).

Kiyoshi
 

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shay2nak
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Discussion Starter #6
Hypothetically speaking. Can we get straight cut gears for the Elise? I like that whining noise. Also, if straight cut gears are stronger why don't car companies use those? Just the noise? That's funny.
 

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You really don't want straight cut gears for the street. I have read that they are anywhere from 5% to almost 20% stronger, but they make terrible noise. Most cars have a straight cut revers gear, especially smaller japanese cars. They whine at even 10 M.P.H. If stronger gears is something you want, you should have the tock ones cryogenically treated, and leave it at that. I would think you would have to be making a lot of power for the gears to go bad, especially on a NON AWD car. :cool:
 

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I think that the main reason is that there is less power loss in the drive train with straight cut gears.
 

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shay2nak
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Discussion Starter #10
originally posted by Mean TT
Most cars have a straight cut revers gear, especially smaller japanese cars. They whine at even 10 M.P.H.
yeah! ok, that was going to be my next question. About the reverse gear because I have 2 Civic coupes. That whine is pretty loud!

But is it possible to buy a straight gear transmission for the 2ZZ engine? Patricko is also saying that there is less power loss also. Well, this type of transmission seems better than helixical.
 

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Khamai and Patricko are correct. Straight cut gears make the whining noise. To alleviate that noise, most transmissions use helical gear teeth.

The greater power loss is due to the greater surface area meshing with each other on the helical gears. (Straight cut gears have less surface area, thus less parasitic driveline losses.)

As for straight cut gears in a street driven vehicle: I don't recommend it. It'll drive you crazy. I've driven plenty of vehicles with straight-cut gears (mostly NASCAR Southwest Tour cars) and you can hardly think in those cars. The whine would get annoying quickly.

Bob
 

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Agreed, straight cut gears are not worth the very few horsepower they save! The noise is really bad on the street, forget listening to the stereo/radio.
 

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Why not just get one of those whistles that mount on your exhaust pipe? It'll sound similar.

If you can stand that for 6 months remove it and get the straight cut gears.
 

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I love that "demo" drive as they pull out of the shop, nearly side-swipe the parked car, and appear to have a totally ineffective WooWoo for their effort. Remind me to stay out of Oakland. Shouldn't be hard.
 
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