Are the side exhaust covers insulated from the factory?

Walter Clark

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My '94 has a pair of heat shields consisting of a white insulating blanket sandwiched between 2 layers of thin stainless steel that was installed on the backside of the side exhaust covers. Was this original or was it added somewhere along the way?

The reason I ask is twofold. First, the covers on my car dont seem to get nearly as hot as others report...certainly not hot enough to burn someone just touching them. Second, these heatshields were half *** installed using a few random sized pop rivets thru the side exhaust covers and many of them werent even holding anything. I drilled them all out in order to remove the shield and clean up the backside of the covers which were full of dirt, stones, leaves, etc. sandwiched between the covers and shields. Then I reinstalled them using SS machine screws, fender washers and nuts using the original pop-rivet holes in the side covers.

The official parts lists dont seem show the heatshields on any of the gen 1 or 2 cars, but if the shield was something that was completely integral to the cover or a dealer add-on maybe they wouldnt be in the parts catalog.
 

Monopoly

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Was it this?


Scroll down to Dodge Viper (1992-2002) Side Sill High Tech Thermal Insulation Kit. My Gen 2 cats and resonators are **** stock. The front part of the sill where the Cats are gets really hot. Looking at switching to high flow cats next season.
 
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Walter Clark

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Mine are different than the kit in the picture. The 2 differences are that mine dont wrap around the exhaust, they are formed then attached to the shape and curvature of the inside of the side covers, and the insulating material is sandwiched and encapsulated between 2 sheets of thin (maybe 30ga) stainless steel. I will be changing the radiator out in the next few days, so if I have a chance I will pull one of the side covers off and take a couple pics (Edit: pic below from a parts supplier site is just like what mine look like).

By the way, functioning cats will always get hot, high flow or not. Rally cars require working cats as they are part of the required emissions to be road legal. We used to inspect for functioning cats by checking the surface temperature of the cat at the inlet and outlet ends. We expected to see at least a 100F gain in temperature when a working cat was warmed up from use. Eventually we were told to drop that way of checking them, but in my experience the check held true unless the cat had been gutted.
 
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MoparMap

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Those sound very similar to what I have on my gen 3. I wonder if someone retrofitted the later model heat shield to your car maybe? The gen 3+ shields are pretty much held on the same way, just a pair of screws at the bottom corners. Mostly just there to keep it in place while installing as it more or less just gets stuffed between the muffler and the side sill, so nowhere for it to go and it's formed in such a way that it contours pretty well and can't move around much.
 
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Walter Clark

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That makes sense. I took a look at the '05 and '06 parts catalogs and the heat shields drawn in the Exhaust section could be what I have. Found an image on a parts site. That is what mine look like.
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Thanks!
 

MoparMap

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Interesting to know that that seems to be a pretty good solution for the earlier cars though. Always nice when you can use factory parts, though wonder if they didn't do some trimming to get those to fit on the earlier car.
 
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Walter Clark

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It wasnt immediately obvious to me that they were trimmed, but the metal should be easily cut by airplane shears / tin snips if needed.
 

njsteve

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My '94 has a pair of heat shields consisting of a white insulating blanket sandwiched between 2 layers of thin stainless steel that was installed on the backside of the side exhaust covers. Was this original or was it added somewhere along the way?

The reason I ask is twofold. First, the covers on my car dont seem to get nearly as hot as others report...certainly not hot enough to burn someone just touching them. Second, these heatshields were half *** installed using a few random sized pop rivets thru the side exhaust covers and many of them werent even holding anything. I drilled them all out in order to remove the shield and clean up the backside of the covers which were full of dirt, stones, leaves, etc. sandwiched between the covers and shields. Then I reinstalled them using SS machine screws, fender washers and nuts using the original pop-rivet holes in the side covers.

The official parts lists dont seem show the heatshields on any of the gen 1 or 2 cars, but if the shield was something that was completely integral to the cover or a dealer add-on maybe they wouldnt be in the parts catalog.
It was the factory that half-assed installed the heat shields with pop rivets. From 1992 to 1997 that was how the heat shields were retained in the sills. It was not a very intelligent method as the rivet was steel and the side pipe covers were aluminum. Now, who here remembers their high school chemistry class on electrolytic reactions? Dissimilar metals plus moisture creates a mild electric charge that degrades the metal at the meeting point.

This caused paint blistering at the rivet sites which led to a TSB 23-59-97 being issued by Dodge for the replacement of all those side pipe shields on Dodge's dime. That's how I wound up with a spare NOS set of the new rivet-less heat shields in 1997. They are still in my basement as spares.
 

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MitchGola

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I came across your post, and it got me curious about the side exhaust covers on your '94 car. The heat shields you described with the insulating blanket sandwiched between stainless steel layers sound interesting. It's hard to say for sure if they were original or added later on.Regarding the heat levels, it's possible that the shields were indeed designed to provide insulation and prevent excessive heat transfer. It's great that you took the initiative to clean up the covers and reinstall them using more secure hardware.If you're looking for quality bolts and screws for your car projects, you might want to check out the Scrooz webpage. They have a wide selection that could come in handy for various automotive applications.
 
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