As I am driving, say for example 30mph and I let go the gas something is making noise underneath the front wheels. It seems as if the exaust system where the catback meets the high-flow cat, maybe the gasket is completely worn and metal rubbing on metal ?...but when I am back on the gas, the noise disappears...I am currently on Comp Clutch kit with light flywheel..

 

it increases during noisehmm could be wheel bearings.

 

some downpipes hit the oil pan it could be that. explain the sound that your hearing more. is it a quick thump or what

 

If it were your clutch/flywheel you would feel serious vibrations in the cabin. I wouldn't be concerned about it being that. It's more than likely in you exhaust or suspension.

 

could it be tie rods ? The noise is only during off accelerations, it rattles from the bottom around the front wheels

 

I would just jack the car up and check along the exhaust system if its rubbing anywhere you will be able to tell because the metal will be shiny. If no then you can check you steering system, have either a helper shake tires/ steering wheel and anywhere that moves oddly can be worn, also does the sound go away when you turn one direction or the other (if no this rules out wheel bearings). Check for loose bolts. Other than that stuff I would just say its clutch chatter from the flywheel, the vibrations usually associated with that can either be absorbed by oem motor mounts sometimes, or ignored if you have poly mounts and just chalk the vibration up to the stiffer mounts. But because its on decel only I would guess clutch chatter but also a guess without looking at your car so take it with a grain of salt.

 

My front sway bar was hitting my down pipe. Couldn't see it with the wheels off the ground because the sway bar moves with the suspension. Had to look at it with car on a flat rack.

 

Is your clutch a sprung hub? A lot of aftermarket clutches have decel noise especially solid hub clutches. It is probably just the clutch making the noise.

 

im having the same issue but at around 55-60mph. if I let off the gas I get a noticeable vibration under the car (seems to be around the transfer case area). at the same speed, if I throw the car in neutral...no vibration. I've had my exedy triple plate clutch for a over a year and never had this noise. can anyone help?

 

i was thinking clutch noise too, like the Exedy twins make a chattering noise unless its under a load then it goes away

 

i'm going to check my flywheel bolts and make sure they are tight. fingers crossed that will do it.

 

Mine does the same thing as the OP. I think its the clutch disk dancing around. It has had no ill-effects on my car. Makes 579hp and is daily driven.