81 resonation in cockpit

[Derster]

I am getting a resonant sound at 55 and up, it starts there and stays till wind noise and other sounds combine to make it indecernable. No vibration is ever felt, rear susp,joints,shafts seem ok. Have altered the exhaust and no change either(except I can drown it out with my foot now,heh-heh). How about those Goodyear Eagles, they were on it when I bought her and too good to consider replacing, but I feel its a possiblity. Any ideas!

 

[Yoda]

I am getting a resonant sound at 55 and up, How about those Goodyear Eagles, they were on it when I bought her and too good to consider replacing, but I feel its a possiblity. Any ideas!

I would say you have found your problem or at least the majority of the noise. I took my "Gator Backs" off and put them in storage and went with a softer rubber. I went with Remington 120; 255/60/15 and the road noise, handling and ride improved dramatically. Back in 1980 I had a new '80 and went to the T/A 255/60/15 "H" and did a lot of autocross racing, they were by far a better tire all around, pump them to about 40 lbs and they stuck like glue, run about 31 lbs for normal driving and they greatly improved the ride and road noise, plus I could keep it going straight down the road without wanting to jump up the worn highway grooves.

As a side note some 78 ~ 82 Corvette owners would love to have those "Gator Backs".. if they aren't that important to you,,, you may find you can sell them for enough to replace them with a nice set of T/A's or another softer rubber tire and improve the handling and ride..

 

[c4ever]

Ditto
I got rid of the GY for Dunlop on the 85 and went with T/A on the 82. No comparison in both cases. Keep in mind that just because you have good tread doesn't mean the tires are road worthy. Goodyears IMHO tend to dry out and become hard thereby giving very poor performance. I guess this could happen with any tire but any HP Goodyear I've owned has given me this problem. I'm sure many will disagree, but that's what makes it so interesting:argue

 

[resto75]

If its a exhaust resonant sound and you have dual exhaust you may need to have a crossover pipe installed. Is it a tire noise or a humm like sound ?

I get a humm sound from mine at speed and it does get annoying. I need to get a crossover installed but haven't gotten to it yet. I just turn the radio louder for now.

 

[Derster]

Thanks for the info. I did not notice any change with the sound even after I removed the cat and replaced the mufflers,still have the single exhaust. I had very noisy GY's on my truck and replaced them with coopers, incredible difference.
Thats why I suspect tires may be the culprit.