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| View Poll Results: Whats the source of the turbine sound when engine revs | |||
| Noise comes from the spining fan |
   
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22 | 66.67% |
| Noise comes from the timing chain spining |
  
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11 | 33.33% |
| Voters: 33. This poll is closed | |||
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Readers poll Lets see if you know........
When listening to the wheering , whistleing, sound your engine makes do you know what the source of the sound is.
Today I found that my original thought was not actually correct. I hope what I found is true otherwise something is wrong. Does the sound come from the fan ? Or does it come from the timing chains spining ? Kurt Williams
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Never drive faster than your gaurdian angel can fly. 82 SC w/965S eng and G50 6:1 hp/w ratio 72 911t 2.6 twin plug and 72' 911t 57k orig 1 own miles 65/66 912 1 owner 76k orig 01' Aston Martin DB7 V12 Vantage Coupe 6spd |
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06-10-2002, 03:23 PM
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Join Date: Jun 2000
Location: bottom left corner of the world
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I had always hoped that noise is from the fan
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06-10-2002, 03:36 PM
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Looks like knowbodys sure. 20+ LOOKERS and only 3 votes . This should be interesting and educational for some of us . But this poll is to find out what you think not what you know for sure.
Kurt Williams
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Never drive faster than your gaurdian angel can fly. 82 SC w/965S eng and G50 6:1 hp/w ratio 72 911t 2.6 twin plug and 72' 911t 57k orig 1 own miles 65/66 912 1 owner 76k orig 01' Aston Martin DB7 V12 Vantage Coupe 6spd Last edited by pjv911; 06-10-2002 at 03:44 PM.. |
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06-10-2002, 03:40 PM
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I proudly voted for the fan. I hope I'm right....
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1975 911S (in bits) 1969 911T (goes, but need fettling) 1973 BMW 2002tii (in bits, now with turbo) |
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06-10-2002, 03:52 PM
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Fans: people have said they noticed a difference when they changed fans. Since there is also a distint noice from the air cooled motor, it must be the fan. But then again, other cars have fans and don't make that sound.
Chain: Interesting. Although other cars have chain driven components, the Porsche motor does emit a unique sound. It's as identifiable as a blown motor (that is a motor with a blower.) And the Porsche does have all those chain ramps and tensioners to increase the noise level. So it could be the chain. At this point I'll pretty much believe what you say. You could convince me of either one. That said, I voted for the fan b/c that's what I always thought.
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.. Last edited by pbs911; 06-10-2002 at 03:55 PM.. |
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06-10-2002, 03:53 PM
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Join Date: May 2000
Location: Los Alamos, NM, USA
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Turbine sound? Do you know what a gas turbine sounds like? I've heard the "whine" of aircraft turbines, stationary power gas turbines and truck mounted high pressure frac pump turbines. None of them sound like a 911 engine. For one they're a hell of a lot louder plus the frequency is higher. Having said that, I would guess the characteristic 911 sound is actually a mixture of the fan noise, the exhaust note and timing gear drive train with additional interesting effects from the sound bouncing off the ground or close adjacent vertical surfaces. Cheers, Jim
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06-10-2002, 04:03 PM
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Actually ... the term noise is inappropriate. Melody, music, or concerto seem more accurate!
I think you left off a couple of other choices ... c. Exhaust d. Both A & B e. Both A & C f. Both B & C g. ALL ! And, on that basis, I abstain from voting! Without a recording made with one or more very expensive microphones ... and rather exotic spectral analysis and processing similar to that done in the movie Sneakers, a definitive answer is impossible! And, of course, individual ears and brains process the information differently and reach different conclusions!
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Warren Hall, Jr. 1973 911S Targa ... 'Annie' 1968 340S Barracuda ... 'Rolling Thunder' |
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06-10-2002, 04:26 PM
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I'm a fan Fan.
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Robert Stoll 83 911 SC 83 944 |
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06-10-2002, 04:35 PM
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HERE`S THE ANSWER TO THE POLL
Warren you didnt have to complicate it. You know what im talking about. Today I changed my 1.8 ratio fan pulley to a 1.3 ratio. When I was waiting for the correct belt to be delivered I started it up with out the belt and found that 90% - 100% of that familiar whining sound came from the chains. After putting on the belt the sound was identical to the sound without the belt. My chain sound may be particulerly loud because my chains gears tensioners(oil psi feed) and ramps are all under 500 miles. I love that sound and I am very happy it did not get quieter by slowing the fan speed. I did hovever notice a power increase at higher rpm`s.
Kurt Williams
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Never drive faster than your gaurdian angel can fly. 82 SC w/965S eng and G50 6:1 hp/w ratio 72 911t 2.6 twin plug and 72' 911t 57k orig 1 own miles 65/66 912 1 owner 76k orig 01' Aston Martin DB7 V12 Vantage Coupe 6spd |
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06-10-2002, 04:38 PM
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Green Skull 006
Join Date: May 2002
Location: Rhode Island
Posts: 2,040
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No kidding, I always assumed that it was the fan.
Jim '55 Speedster (gone but not forgotten) '86 Carrera |
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06-10-2002, 07:48 PM
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Location: Santa Clara, CA
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Well, that would rule out the fan. But it doesn't mean the music comes from the chains.
Next remove your chains and see how it sounds
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Chuck Moreland - elephantracing.com - vonnen.com |
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06-10-2002, 08:02 PM
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Location: AZ
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perfect 911 sound recipe..
1 part transmission.
2 parts cooling fan. 2 parts intake. 3 parts timing chain. 3 parts exhaust. Heat to 6000rpm, stir, and enjoy! 
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06-11-2002, 10:57 AM
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Too big to fail
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Music? Hah!
I keep hearing this pap about "music" from the back.
Where could you possibly get the idea that it's music? In my car, it sounds like I'm being chased by 6 oversize German rugby players after uttering some off-color remarks about their mothers' relationship(s) with various barnyard animals and how it directly relates to their genealogical provenance as evidenced by their less-than-savory countenance.
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"You go to the track with the Porsche you have, not the Porsche you wish you had." '03 E46 M3 '57 356A Various VWs |
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06-11-2002, 12:06 PM
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Not Quite Banned
Join Date: Dec 1999
Location: Ft. Lauderdale
Posts: 1,222
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I always thought it was coming from my wife...
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Thomas Owen 1972 911T 1972 911S |
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06-11-2002, 12:16 PM
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1969 Porsche 911 2.7 
1975, 1969 Porsche 911S, 911T 2.7S CIS, 2.0T ca
1978 Porsche SC Targa 3.6
