I installed some energy suspension motor mount bushings about a month ago. I love the damn results but now Ive got a small annoyance. Around about 3000rpm the engine vibration sets up a resonance wave along the heat shielding above and on the cat (makes a wonderful noise).
So Im going to remove the heat shield bolted to the cat and the heat shielding bolted to the frame. What Im wondering now is will there be a large enough gain in heat energy to melt the sound deadening material inside the cabin above the cat?
If heat is going to become a huge problem Ill probably just wrap the cat in some Heat Wrap.

 

hey bill what car do you have again? and what Exhaust mods? Cat Back? header? I know that my aftermarket exhaust doesnt have heat shields and you can feel the heat inside of the compartment if you stick your hand inside of the center console through the little e-brake hole thing....

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Have you had your V8 Today?

2000 Milano Red Si
Greddy SP Exhaust
Lowered 3.25
Red Valve Cover
Pioneer P700 CD Player.
JL Audio XR 5.25 Splits
Sony Mobile ES 3 way 6x9
Autometer Air Fuel Gauge
Removed H Logo in Grille
Removed CIVIC from Back Bumper.

 

Ive got a 98 Honda Civic Ex coupe.
Exhaust mods are a header and catback.

Youve got no heat shielding around the cat and have no problems?

 

If you want to keep the heat shield you could try to use some sort or rubber bushings to guard against vibration rattles. If you want the shield off and not to fuck with it but are a little worried about heat you could always just wrap it with header tape.

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-Aaron
96 Red Camaro Z28 A4 TampaRacing.Com Sticker (16hp gain)
SLP 1 3/4 headers flowmaster cat-back !cat 3.73 GM Motive gears MSD 6A MSD 8.5mm Wires HPP+ 160 Stat.
Best ET so far...13.1@105.5

 

Rubber bushings might not withstand the heat.
I guess I could always use some RTV sealant as a buffer.

Im just gonna remove the shielding and see how it goes. The only problem with Heat Wrap is it tends to trap moisture. With the cat being totally exposed to the elements it could rust up pretty damn quick.

 

hey bill is it a DC Sports header? If so the rattling is coming from the header b/c the donut ring they send you is the wrong one... call DC if it is and they will send you the correct one...

------------------
Have you had your V8 Today?

2000 Milano Red Si
Greddy SP Exhaust
Lowered 3.25
Red Valve Cover
Pioneer P700 CD Player.
JL Audio XR 5.25 Splits
Sony Mobile ES 3 way 6x9
Autometer Air Fuel Gauge
Removed H Logo in Grille
Removed CIVIC from Back Bumper.

 

Nope fraid I got the cheap Focuz header.
Didnt feel like paying 300+ for a damn header only payed like $110 for mine. Its better than the OEM exhaust manifold and thats good enough for me.

Now that Ive defended my header nope its not the gasket.

 

The tape shouldnt hold water for long since the converter heats up well past 200 degrees. Also Ive seen high temp bushings and spacers at the hardware store.

 

True the water will evaporate quickly but the crap it was carrying will be left inside the heat wrap and trapped against the cat.
Over time the mineral deposits and other matter will start to eat away at the metal.
Probably wouldnt be so bad to do it down here as up North (road salt) but still dont like using wrap.

Ive got the shielding off and Ill see how it goes.

 

Hey Bill. I am not running any heat shields on my delsol. I have not since last year and there are no adverse affects besides the temperature inside the car is a little warm after hard driving. The heat shield around the cat really only serves the purpose of helping the cat atain operating temperature faster. I had to remove my rear heat shield above my exhaust piping because my new header pushed the whole system back about a half inch causing the pipe to vibrate against the shield making the same really annoying vibrating sound that you seem to be experiencing. After removing the sheild everything was great.

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TampaSol
94 delSol VTEC
00 Civic Si
http://go.to/ourcars