Plus the roads around me vary greatly in sound from new asphalt to concrete, to old asphalt, to tar/chip over asphalt. It will still be interesting to find out.

 

On the drive home this afternoon, smooth pavement, 80mph - 73db.

 

If you find you are louder than the others I suggest you check your bearings in the area you believe the sound is coming from. I long blamed my Volvo's tires on what turned out to an intermitent bearing problem.

 

If the sound is too loud and it's not something failing, maybe a sheet of Dynamat in the hatch area?

Dynamat.com | Dynamat Sound Damping | Thermal Solutions

 

I've been running Hankook Noble S1 tires for several months now, and they are by far the quietest tire I have run on my srt coupe so far. If you are tired of road noise, these make a huge difference.

 

When I get new tires, wear and noise will be one of the deciding factors, after price. This car handles far better than anything else I drove in the past, and if anything I drive more pedestrian now in it.
So unless the Hankooks aren't made with unicorn hair or something even more expensive, I may try them. I am please how quiet the Crossfire is in general with the windows up and radio off. When I first test drove one with 29,000 miles I was confused when I heard the spoiler go up.

 

I just had a new set of old gen 'kooks installed today that I got last year on closeout from TireRack. They sure are quiet.

 

Yesterday UPS brought me a new set of Hankook Ventus S1 Noble2 that I had ordered from DoscountTireDirect...$659.56 delivered! Will have them installed locally (2 blocks from my house) tomorrow for $15 per tire. All in all, a great price, just hope that they are as quiet as yours.

Don

 

I had a new set of Hankook V2 Ventus installed to replace the same tires at 25,000.
Sure is quiet again.
The old tires only required replacement due to toe and camber being so far out on the right rear that the inside of the tire was almost down to the core.
( installed the $80 DIY set of adjustable rear camber links and all is well now )
Anyone want a set of 3 V2's with maybe 10K left on 'em is welcome to come by and pick them up ( free ).
I WILL NOT SHIP !!!

 

Well, we installed them today and WOW, what a difference in sound. From 78dB down to 68dB! I can now take someone for a ride without being embarrassed about the road noise. The rear tires were cupped bad and badly worn on the inside (especially the passenger side one).

BTW - I tried the app that was mentioned in this thread in two vehicles and it showed 9dB higher than my real dB meter.

Don

 

You need to order the parts from Speedway.com for the DIY rear camber links, set them to the OEM 30 cm center-to-center, install them, then take it to a good laser alignment shop before you also destroy your new set of tires.
This is exactly the condition I had - right rear worn out and cupped on the inside edge.
My rear toe in as well as the camber was WAY off.

Item Part # Price Qty Total
Speedway Forged Steel 4-Bar Rod Ends, 5/8-18 RH Thread Straight Shank 91008001-STR $12.99 2 $25.98

Steel Jam Nut, 5/8-18 RH 1750246 $0.99 2 $1.98

Speedway Forged Steel 4-Bar Rod End, 5/8-18 LH Thread, Straight Shank 91008002 $14.99 2 $29.98

Steel Jam Nut, 5/8-18 LH 1750446 $0.99 2 $1.98

8 Swedged Steel Tube For 5/8 Heim 91034258-8 $9.99 2 $19.98

 

Nice that you posted finding the solution to your problem. That will help others.

Now that I think of it when I purchased my car it had a similar noise but in my case it was speed related. The seller slickly explained away it away but in fact the noise was not corrected until I switched out the rear tires which had flat spotted due to lack of rotation. I had forgotten about that.

 

A much cheaper solution is a piece of Volara foam underneath the cargo mat. Right now it's a piece of white but it comes in black and I think it's just as good as Dynamat and much less expensive.

 

Where do you get this ? And what thickness do you use ?

 

I just bought a DB meter off of E-Bay will be here on Wed. with my new Flowmaster muffler which is loud but love it so next week will report the music of my new muffler LOUD. my first reading in 2nd gear at 30 mph 107 DB will take more readings later.

 

Got a reading with the app mentioned at 60 MPG of 80db Stock SRT-6 on average road not super smooth and not real rough pavement.
General G-Max AS-03 tires.

 

I am not familiar with your tires but as I previously mentioned the app showed 9dB higher than my real dB meter so your sound level may be only about 72dB. IMO 80 would be very loud and not acceptable. In fact, I did not think that 78dB was acceptable thus I put on four new tires which brought the sound down to 68dB. OTOH, my CF is NA so maybe that makes a difference...never been in, or even seen, a SRT-6.

 

Mine is not bad, but when I had a cooler malfunction at Woodward, the rear trunk area got very damp. I remove the trunk floor (no actual water underneath, just everything that could absorb water did) and drove that way for 2 days. It is amazing how much road noise there is just with that 1 piece removed.

 

Wow you're missing a TREAT !
I can't complain about the cabin noise, can hear the exhaust and it is stock exhaust which I love ! Don't have to yell to talk to passenger so, no problem. As you say app maybe off some 72 db may be more correct.

 

Maybe some Dynamat under the trunk cover would make it even quieter ? Anyone try ??