Resonance at around 70 MPH?

[Six]

Why don't you make a video of the noise and post it so we can hear it?

[Subie]

Originally Posted by Six

Why don't you make a video of the noise and post it so we can hear it?

I can try, but I'm not sure how well it will show up on my iPhone. The roads around me are very poor and generate a lot of tire noise as a result.

[ap5512]

Yesterday i heard the same resonance noise going near or at 70 mph. To me it sounded like a vacuum type sound. It wasn't scary or that concerning but it was in and out noise.

I am also experiencing the other noises other members have been complaining about...the whining/chirping noise...and the clatter/chatter when shifting into neutral and braking.

[Bacon]

Its a sports cars. Sports cars make noise.

[Snoopyalien24]

Originally Posted by Bacon

Its a RACECAR. Racecars make noise.

FTFY

[Subie]

Originally Posted by Bacon

Its a sports cars. Sports cars make noise.

Good noises, not bad ones.

I suppose you enjoy the DI cricket sound, and the rear deck tapping/popping sound? Because race car?

[ruskymx]

I have this same noise. I describe it as like striking a tuning fork, but constant and doesn't fade away. For me it is most noticeable between 60 and 70mph and it doesn't matter if it's in 5th, 6th, neutral, clutch engaged or not. I though it was a bearing noise at first. I had the noise since day 1. I had a tech at the dealership that I work at check it out and he couldn't find anything either. He did have me try some things to see if they affected the noise and also to take note of speed, gear, etc. It's documented at a few hundred on the ODO that I complained about the noise.

Ruskymx

[brett_g]

I can't believe this thread is this long. Have any of you guys actually owned cars with modified exhausts? It's exhaust DRONE it happens at certain RPM's /speeds. Sheesh. If you wanted a dead silent car, you shouldn't have bought this thing..

[Subie]

Originally Posted by brett_g

I can't believe this thread is this long. Have any of you guys actually owned cars with modified exhausts? It's exhaust DRONE it happens at certain RPM's /speeds. Sheesh. If you wanted a dead silent car, you shouldn't have bought this thing..

/sigh

If only you understood what was going on you would realize that this is not an exhaust noise. It's NOT ENGINE SPEED DEPENDENT. It's VEHICLE SPEED DEPENDENT. Get it? Got it? Good.

[russv]

I went out and did the 35 mph and 70 mph sound test and noted the sound described at both speeds. It seems to come from the rear of the car. I think there are 3 possible theories:

1) The tires create the harmonic which is then amplified through the body of the car.
2) The exhaust creates the harmonic
3) The rear differential creates the harmonic

I'm tending to rule out the tires as the harmonics are at differing speeds. (My opinion, I could be wrong).

Having owned rear wheel drive cars in the past I have experienced drive train noise. Consider that you are dealing with 3 components: transmission, drive shaft, and differential.
I've also experienced cars with exhaust systems that demonstrate a harmonic sound, but it is usually over a certain RPM range and not necessarily speed related (Mini Cooper, various Hondas).

My money is on the drive train, probably drive shaft/differential. That said I am not too concerned at this point, unless it gets worse. Probably a normal sound.

AND, let's keep the discussion civil because it appears to be endemic to all our cars and is a concern to some.

[industrial]

I've tried to listen for this resonance. I don't notice it at all.

[Subie]

Originally Posted by russv

I went out and did the 35 mph and 70 mph sound test and noted the sound described at both speeds. It seems to come from the rear of the car. I think there are 3 possible theories:

1) The tires create the harmonic which is then amplified through the body of the car.
2) The exhaust creates the harmonic
3) The rear differential creates the harmonic

I'm tending to rule out the tires as the harmonics are at differing speeds. (My opinion, I could be wrong).

Having owned rear wheel drive cars in the past I have experienced drive train noise. Consider that you are dealing with 3 components: transmission, drive shaft, and differential.
I've also experienced cars with exhaust systems that demonstrate a harmonic sound, but it is usually over a certain RPM range and not necessarily speed related (Mini Cooper, various Hondas).

My money is on the drive train, probably drive shaft/differential. That said I am not too concerned at this point, unless it gets worse. Probably a normal sound.

AND, let's keep the discussion civil because it appears to be endemic to all our cars and is a concern to some.

1) From past experience with tire noises, there is at least some change in the character of the noise depending on the road surface. I've noticed none on all the different pavement types I've driven on, including rough asphalt, smooth asphalt, concrete, etc.

2) The noise does not sound at all like it's coming from the exhaust to my ears. I have not tried clutching-in at 70 MPH to see if there is any change in the character of the noise, but I am extremely skeptical that there would be. Also, you are reporting the noise with an automatic transmission vehicle and I am seeing it with my manual transmission; the difference in gear ratios would mean that the engine is spinning at different speeds between our two cars. For us both to hear the noise at the same speed seems to rule out the engine (and my extension, the transmission and the exhaust) from being the culprit.

3) I don't recall if the final drive is a different ratio between the automatic and manual cars, but regardless, that is only one component of the differential. The LSD itself is the same. I, like you, tend to think the noise is coming from the differential or another component in the driveline.

It should not be too difficult to identify the source of the noise if we can get Subaru/Toyota interested in doing so; as I have stated before, I do not feel that the noise is normal and will insist upon it being addressed.

Originally Posted by industrial

I've tried to listen for this resonance. I don't notice it at all.

This is but one reason why I don't buy that the noise is normal.

[russv]

Originally Posted by industrial

I've tried to listen for this resonance. I don't notice it at all.

My ears are pretty sensitive to car sounds so it's something I notice. It could just be a natural resonance from the body. I'm at a bit of a loss.

[Bacon]

Originally Posted by Subie

Good noises, not bad ones.

I suppose you enjoy the DI cricket sound, and the rear deck tapping/popping sound? Because race car?

I dont own a BRZ or FR-S. Performance cars of this price bracket generally make all kinds of noises.