phoneman91

For those that had the distinct pleasure of having owned a C5 coupe and C5 convertible--I have a question: Which is quieter on the highway at speed with the panels removed and the top down (60MPH and higher)?

Can the radio and passengers be heard equally in both at the same speed? Or is one of the two type more quiet at the same speed and ambient environment? I am referring to wind noise and other ambient noise.

I have a convertible and am surprised how quiet it is at highway speeds.It only gets noisy near Jersey Barriers , sound walls,or above 70MPH.

jackthelad

Coupes get very noisy with the roof on - the tire noise just reverberates around the "trunk" area - gets much quieter when the roof is out.

bigcypress

wifes had a 2000 coupe for ten years and 2004 vert for four years . fuel pump is really loud in coupe and never rode with top down in vert . suspect coupe is quieter . ...ps. never had top off of coupe .

Evil-Twin

They are both the same... tires is one harmonic, wind noise is the other.
Tire noise:
can vary by tire compound ( touring tires; are nosier because of the carbon content 60/40 carbon to rubber ) Performance tires; are quieter because of the carbon content 40/60 and also by road surface.. eg. a black top road is quieter by 20 to 50 db depending on road surface temp. Concrete is much nosier and not as effected by surface temp.

wind noise is another harmonic Both coupe and vert with windows down puts the tires and their noise at 24 inched from your ears. so you get to hear their noise, but that particular harmonic Tire noise ) is overshadowed by the wind noise coming over and around the windshield.

If you have Old run flats with a very hard heat soaked compound the tire noise will over shadow any wind noise..

Tire noise and wind noise is not dampened by any dyna-mat or noise cancelling product. those products are only designed to dampen vibration. There is nothing between your ears and the window opening. windows up glass is the only thing between wind noise and tire noise. windows down leaves both tire noise, road noise, and wind noise a direct shot to your ears...

Lots of urban legend here. Anyone with a DB meter can attest to what GM has already done. The C5 is a sports car, tire to ear distance in very short by comparison.

You can follow the hype and manufacturing hyperbole of sound deadening devices, but if you drive with your windows down, top off or Vert top down, you are going to hear everything that is already there and no amount of dyna mat will effect these conditions.

jdvann

I had a 2000 vert, and the thing that made the biggest difference to me was the Vette Net wind restrictor that mounts behind the seats. With it installed and at highway speeds 70+ my wife and I could talk easy and the stereo sounded great still.

In my 01 coupe with the top off I could not hear my Bose stereo at Highway speeds...

phoneman91

Interesting . Are the noisy tires run flats? And the coupes are more noisy with the tops on--both in the city and highway?

Evil-Twin

Vette Net wind restrictor

Is a product that will cut down on the wind speed inside the cabin but only by a small amount but enough to notice the difference.. but it will quiet down the wind noise but wont do a thing for the tire noise because your ear is closer to the tires than anything else..

This is reality.. no hype here...

phoneman91

I appreciate your nuanced response,ET. You must be very proud to have been part of the C5 development--I sure would be!

Low drag coefficient has it's ancillary benefits.

I must say--I am impressed with the C5 convertible--very well done when it comes to minimizing wind noise and most importantly-- reverse flow wind buffeting . The convertible has very low wind noise and little of the reverse wind flow that some convertibles have. Like a well designed motorcycle fairing and windshield--the best design permits smooth wind flow over the windshield with resultant quieter environment in the interior. I have never been in a convertible that has been so quiet at highway speeds. Very quiet with side windows up and top down at highway speeds.

It is amazing that a 20 year old design--can still work so well and still be competitive with today's best design.And look so good doing it !

Evil-Twin

I spent 80 hours in the GM wind tunnel with the C5 .

leadfoot4

I love driving around with the top off, but the wind noise IS very annoying. If I drive on the expressway with the top off, I use the same earplugs I use when riding the lawn mower around.....

SaxyVette

OK I had both, currently I got a '99 vert,seems like same interior noise in both.. but the '99 Coupe I had buffeted bad at certain speeds with the roof off. The vert is smooth as glass, my choice is the vert unless you favor the more closed car, both my cars are stock exhaust,

Phanni

I had one of each and I think the convertible was marginally quieter, however my vert had <30,000 miles and my coupe had >130,000.

phoneman91

Time well spent!

Forcedvert

Had the top down today, didn't want to rub it in in the other thread. Had a bit of fun with a old 911sc and a newer 370z at a stop light, all three of us stopped on a nice wide open three lane road. I love having a supercharged c5 vert, nobody expects it. I let them take off, I blow past pulling away then back out, no need to stay in it.

Never noticed any wind noise

Vetteman Jack

I have owned three coupes and have not found any of them to be obnoxiously loud when it comes to road noise. Even with the top off it's not that bad to me - but yes there is some buffeting. I guess it all comes down to what is an acceptable level of noise to each individual. I would think tire noise would be about the same in either a vert or a coupe.

jackthelad

Sorry, but after 19 years of living with a C5 and with a background in vehicle engineering, I really don't agree. A lot of the tire/road noise in the C5, driven with top on and windows up comes from the rear cargo area, not through the glass. As a data point, road noise is much, much worse than in my old hatchback 5.0 Mustang. And I have had multiple brands of tires on the C5, none of which make the car much quieter, though the OEM Goodyears were probably the worst once they had a few miles on them. Yes, it's a sports car, but despite all the car's excellent attributes, I still think GM did a crappy job of NVH management.

Evil-Twin

I never saw you in Warren at the wind tunnel never saw you at the Corvette design studio parking lot... so I'm not sure of your qualifications. I, however have been with the C5 design since 1995 through launch in 1997, I have seven proprietary designs in every C5 on the planet, a year of engineering revisions and two years of Engineering field support specific to the C5 and its design before retiring.. So I've been with the C5 for 22 years this coming May

"Sorry" you are not qualified to discuss C5 engineering and its aspects. To say GM did a poor job only shows just how ignorant you actually are about automotive design, how a car goes from a sheet of paper to launch but most importantly you are clueless about how a project is managed and how certain aspects of the builds get more development money than others. But then you would actually have to be a real automotive engineer to know this. The C5 Corvette is a benchmarked design, with the lowest CD and CDA at the time, and the first productio0n car on the planet to offer AH. But then you obviously know nothing about a C5 Corvette.

phoneman91

And you have a coupe for all of that time ?

Evil-Twin

There is a reason why some of us have been thanked 800 times and others just once.. the "thank you" field has only been available on this forum for the last 2 years.

Some members just cant stand it when someone actually knows something about this car, while others embrace it and the years of development insider information that I've shared that cant be found in any book. This a 16 year paper trail on this forum. From the time I was invited here by Troy and Adam after retiring to the present day. lots of very disrespectful legends in their own mind have come and gone from this forum.

There are some very helpful and talented members here on this forum, anyone who has been here for a while knows who they are.. unfortunately most have moved on.

Evil-Twin

If the C5 was perfect you could not afford it.. as I've said many times its the very best bank for the buck be is a C5 C6 or C7... I never once said it was perfect. Dave put most of the budget into the drive train.. Oh that's Dave Hill just an FYI.
We could have put much better seat in the C5, better radio, etc. but the budget wasn't there for those short comings. You would have to know how a concept goes from the design studio to launch. First the demographic is developed through research and actual former Corvette owners feedback. Once the demographic is established, then the cost to build is established.( The budget )
Then the budget is divvied up into sub build groups each with a time line to launch and a budget. project mangers of these groups keep the time line and the budget on track. A C5 corvette has 6000 parts all under the watchful eye of GM engineering through a dozen second and third tier manufacturers all winding up in Bowling Green, all fitting together and working as designed. This all goes from a clean sheet of paper to launch in two years, a very daunting undertaking.

To expect perfection in a 50,000 dollar car with 1/4 million units to build only show a lack of knowledge about automotive design and manufacturing.