Still have vibration/resonance. Wanna test running exhaust out. Flex hose?

I have balanced and straightened everything, zeroed out the pinion angle. New balanced tires all around. And still, when I cruise down the road, there is a WAAAAHRUUUWAAAAAHR noise going on, a vibration really. Only at cruise, not when accellerating and not when I am "on it", if you know what I mean

So, only thing left to check is if it is resonance from my Super44s dumping at the axle.

Without taking it all out and starting over, I want to add to what I have with a temporary fix. I was thinking about clamping on some flexible 2-1/2" exhaust tubing and either side-exiting or exiting out the rear and seeing if the noise goes away. If temp fix fixes it, I will either live with it being more comfortable knowing it is definitely exhaust drone (and not something serious about to fail on me), or maybe add pipe permenently side exiting or over the axle.

Do you guys think the flexible stainless tubing would move the noise out, or would I need solid tubing to accomplish this?

 

my 92 fox did the same thing when my flowmasters dumped at the axle... i put some tailpipes on it and it cleared right up

i dont see why flex tubing wouldnt work... as long as it is just to test it and you dont plan on running it permanently on it... test it out and if it works go get some pipes put on it

 

Hmm this sounds familiar. I still stick with my comments from the old thread. Both my mavs did this with turn downs. Its an exhaust resonance. I wouldnt even bother with trying cheapy pipes to diag it. Just wait till you get tail pipes and it will be mostly gone.
My car had similar issues to yours with other driveline vibes like the wrong ujoint caps but the resonance is still there and always has been. You can try pointing the turn downs side ways toward teh rockers. Not sure if it will help or not. Mine are welded so I havent tried it. Tail pipes for me eventually anyhow so I just live with it.

 

im having a similar problem with my 2 door. i think it's where my pipe bends over the rear end in an arc and then turns down.
would cutting just after the muffler fix this or just make it loud and annoying?

 

Scoopers car and mine are already turned down at the axle. Its loud and resonates on the HWY.

 

Mine is turned down right before the axle (we call it turned down AT the axle).



I can twist them at the front flange a bit either way, probably easier to twist them so they angle toward each other.

Not sure if you were the one that planted that "exhaust resonance" bug in my ear in that other thread (I am not going back to re-read it, so I will give you credit :Handshake), but after trying everything else out, I am starting to believe that the problem lies there.

If it was some other source of vibration, it would most likely have failed me at this point, since I tend to run this thing so hard, with 6500 and 7000 rpm shifts and mostly highway driving.

 

I have heard of guys aiming them toward the ground at the center of the car. Any idea if that will cancel some/all of it out?

Once I verify it IS exhaust, I will probably leave it alone and let it ride.

At least I can stop worrying about u-joints, converters, etc.

 

LOL. Yep that was me. Mine gets tail pipes this Spring for sure. I'll do a before and after in car to compare.

 

my friend and his dad ran their 68 and 69 camaros that way, thats what ill do to my 2 door. i wont run turndowns though just cutouts

i ran dual glasspacks out to the doors on my 4 door (you can check my pics), if anybody wants smooth driving thats a sure fire bet.

 

When you say "cutouts", do you mean just straight cuts, no bends?

I could cut the bends off and put on 6" straight back pipes, if that is what you are talking about. I could do that myself, no problem.

Will that cut back on noise?

How about legal? I assumed they did turn downs because they had to for legal reasons.

I had side exit glaspaks, I really liked them. Quiet until you drove over a bridge or by a retaining wall, then it would bounce back and hit you in the side. Cool...

 

i rember the old thread but dont rember what all was in it. i may have sugested this before. is it posssible that the centerline through the trans motor is not point straight down the center of the car. the only way i know of to check this is to check the operateing angles on the ujoints. compare their side operating angles. that is difficult to check. they make tools to check operating angles but they are usually for up and down not to the sides.

 

Dose it make noise on and off of the throtle? Drive at the speed the causes vibration put the car in neutral and shut it off and see if you still have the vibration. That should narrow it down.

 

i call "cutouts" where you add nothing after the muffler or cut the pipe straight after the muffler. im going to take a reciprocating saw to mine and get rid of the bend over the axle the last owner added (which i assume causes the vibrations), so it stops after the muffler. dads gonna run it like the picture above though when i give it to him to restore.


in ky. anythings legal just about , no testing or nothing and most cars need it in my town, mainly those stupid crotch rockets

i know what you mean on the side exhaust, my 4 door was loud next to others on the road. i couldnt run it straight back though like i intended, no room unless i move the gas tank to the trunk.

 

no prob louder it would just not throw up the dust like your current setup

 

Bryant, I am sorta being forced to think it is exhaust resonance because i have changed everything, including engine, transmission, converter, u-joints (twice), had driveshaft balanced and straightened, new transmission bushing and mounts, new engine mounts...

Can I go on? New tires X4 and balanced. What else is there?

The only thing staying constant is these damned LOUD Flowmaster Super44s. The description in the Flowmaster website warns of the highest level of interior resonance of their muffler selections.

So, at this point, I need to focus on mufflers/exhaust to narrow down my vibes.

And NO! If I get to the point where the noise is worse, and slam it into neutral...the vibrations stop. But that could be out of balance engine, or transmission, or several other issues.

The main thing that gets me thinking it is exhaust is that it is mostly felt when at a constant rpm, such as cruising. If I am accellerating, and especially if I am up in the 5500-7000 rpm range, it just hummmmmmmms. No vibrations.

I figured if it was a mechanical vibration/imbalance, I would be rattling the car apart at higher rpms, not getting smoother.