I just installed my carsound cat converter and I was wondering if I installed it correctly. Is the heat shield supposed to be on the bottom side of the cat after it is installed, or vice versa? I installed it with the heat shield on the bottom side just like the old OEM that was removed.

Also, using a direct fit cat, I noticed that the outer edges of the flanges started to bend inwards with a bulge in the middle due to the thickness of the gaskets between the cat flange and the muffler and exhaust flanges. I hope I explained that clearly. I'll try to get some pics for more clarity.

Any suggestions?

Troy

 

Heatshield down.

 

Hey Troy,
How was your stock cat after you removed it? Are you plumbing in a complete 2 1/4" exhaust system hence the new cat? Or just putting in a new cat?

 

I'm not sure what the condition of the stock cat was like, because I didn't cut it open. There didn't appear to be any clogging while looking at it from both open ends of the stock cat.

No new pipes, just another cat.

Troy

 

I originally had the heatshield down and then a friend who is a mechanic, told me to install it with the heatshield up in order to protect the undercarriage, especially if it was sprayed with undercoating. I'm sure the direction of flow is correct because my direct fit cat can only be bolted in one direction.

Is the heatshield supposed to protect the undercarriage or reduce the risk of causing fires below the truck? I'm confused...

Troy

 

The heatshield is to dissipate heat from heating up the underbody of the rig. Putting it on the bottom would be pointless as the heat will be dissipated to the open air. The heatshield should be on top of the cat when installed.

Mine was installed professionally, so I think they'd know.

 

Well, that settles it then. I'll leave it with the heatshield up.

Troy

 

 

in todays world, that jsut couldnt be farther from the truth... sure it might be right, BUT in todays world, a lot of these so called professionals are nothing more than idiots with a job....

when i was a tire guy, i had the ASE certified mechanic ask me how to change drum brakes!!!

 

Like I said, mine was installed PROFESSIONALLY by an individual I know is a professional at muffler installs. Why the heck would I take it to an idiot?

The heat shield is just that a heat shield...for the body, not the ground!

 

what i was saying more often then not that the people everyone thinks is a professional is an idiot.....

the ase mechanic i worked with was a professional mechanic and made 2x what i made, but he didn't know how to change drum brakes....

 

Thanks Pat. Maybe I can get her to do her own cat converter!!

Troy

 

I think there are just more idiots in CALIFORNIA...period!

 

nah, there are professional idiots everywhere

 

(yanking hard on foot in mouth) I was always told down-the fire thing. I do see the point of it being up. Will keep in mind next time I need new exhaust though so far all my systems have been 360.

 

isn't it heat shield _down_ on the stock setup?

 

I believe it was. That's why it confused me. Anyway, I like the reasoning for the heat shield being up (protecting the underbelly of the vehicle) and I've kept it that way unless there is a compelling reason to flip it.

Troy

 

I emailed them last week and haven't heard from them yet. Thanks for the suggestion Pat.

Troy

 

The heat shield on the coverter goes down. This is because the thing gets to 1800*F and will light things under the truck (like tall grass) on fire! You will notice there is a heat shield above the cat under the floor of the rig. THAT protects the floor.

Score one for Professional idiots....

 

Okay...I'm no expert on the subject but I just went outside and crawled under my rig and looked at the FSM for my 85.

I noticed several things.

The FSM shows a heat shield above the cat...no heat shield below or on the cat. There is nothing above my cat attached to the floor to protect it, thus I assume that is why it is up like it is. If grass is high enough to hit my cat it is going to be rubbing all that good hot stuff, header, exhaust, muffler etc...at least on my rig.

Don't know the "factual" way that the cat converter god's specify that it be done...but I see the need to protect the floor before protecting the grass.

I think my professional idiot got it right...but perhaps a heat shield in BOTH places is the answer?