LT Texan

I do think I get a lot of road noise. (I'm running Sumitomo HRT's) At 75-80mph, I have to turn the stereo up quite a bit. And at that level, conversations are at the yelling level. I have an app on my iphone and I snapped a screenshot of the db level across frequencies.

Has anyone else measured this? I'm curious if I just need to bite the bullet and buy lots of soundproofing and install it.

James Bailey

Station wagons are always noisy....Porsche added heavy duty foam under the carpets around 1990 then inner fender liners too to try to quiet things down....

Adk46

It's not luxo-quiet in mine. Some is tire noise (Bridgestones), some is wind noise. I recall reading that the noise that comes from the top of the windshield can be addressed with some foam or other material stuffed into a gap.

Wisconsin Joe

I can hold a conversation at normal levels going 75-80. Most of the noise is tires. Some is exhaust, but not a lot.

Wind noise isn't bad. But I have Roger's "Windshield Side Gap" filler thingies installed. It's the wide rubber strip that goes in the gap between the trim and the glass on the sides of the windshield. They help a significant amount.

77tony

What rim/tire sizes are you running on your OB ? T

V2Rocket

If the door/trunk seals are the "bulb" type (hollow rubber tube that gets squished) you can stuff them with 1/4 or 3/8" foam "garage door cord" to make them seal tighter.

martinss

There are a lot of different sources of noise.

Road noise/rumble: I found a tremendous difference is made by the tires. When I got my '90 it had 10 year old Dunlops that had plenty of tread but had hardened. New Bridgestones subjectively reduced road noise by half.

Additional insulation in the footwells - Dynamat/B-Quiet or similar, with acoustic foam on top also made a big difference to road noise transmission. Likewise foam under the hatch carpet.

Wind noise: The windshield noise is more of a whistling noise, and Roger's rubber strips (modelled after the factory strips added to the GTS) address this somewhat.

A lot of other things such as door and hatch strips, side window adjustment, b-pillar foaming, wheel wheel liners, etc. can all make a difference. My '90 is now relatively quiet, but not to the standard of new cars - it's an old car afterall.

fiatrn

A couple weeks ago I took my '86 on a multihour trip across the plains of eastern CO. Cruising at 80 on blue highways, conversation was simple. It is no modern Lexus, but talking required no yelling.

The car has no rear muffler. The previous owner installed some dynamat in the doors. I get a little whistle/drone from the top right side of the windscreen, especially over 90mph. Tires can be a big source of road noise, especially a dronelike hum.

77tony

Drove the GTS for a short time without rear fender liners. Presumed the insulated liners would make a big difference once installed and was dissapointed. The 10" powered subwoofer located in the rear seat delete sure did help a bunch though T

James Bailey

Worth mentioning that most of the cool looking performance tires say M + S rated ....mud and snow and as they wear down they can be louder !! Had one set where I was convinced the rear wheel bearing was real bad and howling...turned out to be just the tires. Now WHY they use such deep and wide grooves other than for looks escapes me since the gaps between tread blocks are not touching the road.....

LT Texan

Carrera III's. 8" front 10" back. 225 and 265.

soontobered84

LT,
Are you sure that you aren't getting rear wheel bearing noise?

The Stepson had gradually gotten so noisy at speed that you could not hear the radio. It took another buddy riding in the car with me to say "Damn, your wheel bearing is noisy!!" to realize it.

77tony

Go to www.tirerack.com and check off a few different tire mfr's for comparison noise levels. Michelin's most always come out on top. Will be in Stamford/New Cannan middle of this week. Black top roads up your way much quieter than most TX roads. T

jcorenman

A couple of data points: I-5 in northern Wash state has a lot of coarsely paved sections (chipseal or stud-chewed concrete) that create a lot of road noise, mostly in the rear. It is definitely tires against pavement and goes away on smooth pavement, but can get very tiring.

We've done two things recently that have made a big difference for our GT: The first is to fit GTS rear fender-liners (trimmed), not cheap but cut noise significantly, maybe by a third. (No dB readings, sorry). The second was fresh tires, Michelin PSS 265-35 x 18 rears replacing the same tires worn close to the wear bars, and another significant reduction. It sounds like what is left is coming through the doors, so we'll try sound-deadener behind the door cards and call it good.

It's not a Lexus and doesn't need to be quiet, I just don't want the road noise drowning out the exhaust note.

Adk46

Jim: How are the GTS fender liners constructed?

If some sort of deadening material is adhesively attached, could similar material be added to regular liners? Could material be added to the inside of the wheel housings themselves? I suppose the noise reduction would not be dramatic, not worth a lot of effort, but if it were easy it might be worth trying.

In my car, it seems like most wind noise comes from the top of the windshield. I might be wrong; I should drive around with my mechanics stethoscope, or cover the area with masking tape.