whats with this now

[hotshotzny]

i spent a good portion of the day replacing my old rusty stock exhaust with a new Y pipe and muffler eliminators and was more than pleased with the rumble thye generate..... but

i took it out for a ride and while sitting at a red light i hear a rattle.. so i pop it in n to give it some gas and it stops... as soon as i put it back in gear it pretty much goes away... once i get rolling its totally gone... so i go straight home and put it back up on the lift and have my fatrher look whil ei sit in it with the car in gear and sure enough the heat shield above the cat is ratlleing.. i check itonce it cools down and cant really see where its originating from... i cant figure out why its rattleing now when i never touched that particular piece and it never made a sound beforead

why on earth would it be doing this... i checked the bolts throughout it and tightened them up and the rattle got a little lighter but it is still there at idle in gear.. pop it in park or N and you can lay right on the gas and not a sound except the rumble of the motor.... and ideas!

 

[compyelc4]

My guess is when you removed the mufflers, substituted different pipes, and probably changed the way the assembly hangs from the chassis, you changed the harmonics of the system causing the cat to vibrate more than normal. As to your idle problem I have not a clue except you may have changed back-pressure in the exhaust. I'd run her awhile and see if the computer "learns" what the heck happened to her ass-end and self-corrects a bit.

 

[hotshotzny]

My guess is when you removed the mufflers, substituted different pipes, and probably changed the way the assembly hangs from the chassis, you changed the harmonics of the system causing the cat to vibrate more than normal. As to your idle problem I have not a clue except you may have changed back-pressure in the exhaust. I'd run her awhile and see if the computer "learns" what the heck happened to her ass-end and self-corrects a bit.

ya must have mis read something... nothing at all wrong witht he idle other than the pipes rattleing... if the computer can fix that id be amazed! the only thing i come up with is the harmonics perhaps.... as far as hanging different its damn near and i mean as close as you can get to sitting in the exact same position as the stock system was.

the car runs great and has more snap off the line than it has ever had right now... just at a damn traffic light i have to pop it out of gear so it doesnt sound like a rattle trapad

 

[compyelc4]

Yep, I read this too fast for my brain <<so i pop it in n to give it some gas and it stops>>. I thought your engine stopped. Been a long day. :eek

 

[hotshotzny]

Yep, I read this too fast for my brain <<so i pop it in n to give it some gas and it stops>>. I thought your engine stopped. Been a long day. :eek

no that would be my luck though!:ugh.. it makes me so mad cuase the thing sounds sick and when you are sitting still it starts to rattle and sounds like crap...... im just hopin some muffler expert chimes in with a fix i havent thought about... and i know all about long days... mine started at 7am on 4 hrs of sleep... worked on this thing and my kids quad all day... if i get a nap now im lucky..then off to work at the bar around 1am..there till probably 6am home and to my brothers wedding at noon...... ;help

 

[dogfish246]

Sounds like your new louder Vette is the cause of the vibration. The extra loudness that the muffler eliminators created casues a little more vibration (from sound waves) which may be just enough to cause a new vibration...

Just a hypothesis. Good luck!
:cool

 

[G Winter]

I would check that shield closely for any cracks. Also make sure
the bolts are still tight against the shield,you may have to install
washers to clamp it tight.I think dogfish is right , the louder system
may be causing new harmonics that are showing up loose part.

Glenn

 

[hotshotzny]

that part i get but what baffles me more than anything is why when at idle in gear....