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What are the best solutions to keep underhood temps. down for 3800SC swaps? by Curtisk1060
Started on: 07-21-2014 12:33 PM
Replies: 25 (660 views)
Last post by: MadMark on 07-31-2014 08:46 PM
Curtisk1060
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Report this Post07-21-2014 12:33 PM Click Here to See the Profile for Curtisk1060Click Here to Email Curtisk1060Send a Private Message to Curtisk1060Edit/Delete MessageReply w/QuoteDirect Link to This Post
Having completed my 3800SC swap last year, I used the magnaflow 12267 muffler w/ 3 inch inlet and dual 2.5 inch outlet pipes, like many others I have seen on the forum. I kept my trunk intact, etc. My main problem has been the high temps. (>800 degrees) just above the exhaust pipes while running for long distances. My rear carpet actually melted in one spot. Since then I have insulated the entire trunk area under the carpet with 1 inch thick industrial boiler insulation, I have wrapped the pipes entering the muffler, next a friend of mine is making another industrial piece of wrap similar to that of a turbo cover for the stock exhaust flange to keep the engine compartment temps down. I also went in and massaged my inner trunk space to provide more room between the exhaust and the inner rear back panel. The stock s.s. heat shield is also still in place with some thinner exhaust wrap mounted beneath it. What have others done to keep things cool? I am thinking about some type of fan just above the exhaust to blow some air out the bottom. I want it to stay looking stock as much as possible for aesthetics, car shows, etc. but wanted feedback on what others have done. Curtis
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Report this Post07-21-2014 04:34 PM Click Here to See the Profile for MadMarkClick Here to Email MadMarkSend a Private Message to MadMarkEdit/Delete MessageReply w/QuoteDirect Link to This Post
I too had a lot of problems with my trunk overheating from the muffler. This last winter I did or had some stuff done. First I replaced all of my exhaust headers with in the front a ZZP P-Log, in the back an after market tubular and the cross over with a ZZP ceramic coated piece. On the cross over I didn't like the look of it so I removed the heat shield and the insulation under it. I then had all of these pieces ceramic coated. I then sent my car to Joe Welch to pull the engine and work on cleaning up the whole swap.

I had him wrap all of the headers and cross over with a double layer of fiberglass wrapping. He also painted on ceramic coating on the rest of the exhaust and wrapped that with fiberglass too, including the muffler. When he put it back together he then moved the muffler about an inch away from the trunk wall and added in a heat shield.

This has really taken care of my trunk heat problem. Before that I had put a doubled up layer of welding mat under the carpet and replaced the melted carpeting, because I had a severe problem where some of the luggage in my trunk caught fire or at least had active charcoals going on in the trunk. That was after a two day drive to Florida from Michigan. So now I feel confident that it will not overheat like it did before. After driving around I can actually touch the top side of the fiberglass and not burn my fingers. I wouldn't touch the flanges though since they don't have the fiberglass wrap on them.

So I have a much better looking engine bay and a whole lot less heat. Thanks Joe (ie. olejoedad)
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Steve25
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Report this Post07-21-2014 04:42 PM Click Here to See the Profile for Steve25Click Here to Email Steve25Send a Private Message to Steve25Edit/Delete MessageReply w/QuoteDirect Link to This Post
"If you fix your car with something from Home Depot, you might be a Redneck".

A ceramic floor tile or two hung on the engine side of the firewall or trunk wall makes an excellent isolator. Like the Space Shuttle.

[This message has been edited by Steve25 (edited 07-21-2014).]

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Fierotregg
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Report this Post07-21-2014 05:41 PM Click Here to See the Profile for FierotreggClick Here to Email FierotreggSend a Private Message to FierotreggEdit/Delete MessageReply w/QuoteDirect Link to This Post
I have a flowmaster type 1 in, 2 out on mine, used the factory trunk heat shield with reflective heat mat under that to take care of the trunk heat. Also vented the deck lid right above where the muffler sits. Some wil say it flows right it flows wrong, either way it gets more air flowing out of the engine area.

[URL=http://s1111.photobucket.com/user/fierotregg/media/Mobile%20Uploads/2014-01/B40C3E54-8CEC-4097-B832-2E9E9BD91B4C.jpg.html][ /URL]
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Arns85GT
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Report this Post07-21-2014 08:29 PM Click Here to See the Profile for Arns85GTClick Here to Email Arns85GTSend a Private Message to Arns85GTEdit/Delete MessageReply w/QuoteDirect Link to This Post
there are a few ways to lower the temps.

1. run a slightly cooler thermostat. I run a 160 on my v8. I ran a 180 on my v6
2. Buy a 3 core aluminum rad. This is a big one.
3. Wrap your exhaust manifolds and particularly your cross over if you have one.
4. If those don't work, add an oil cooler, and if you have an automatic, a tranny cooler too.
5. Add a vent to your deck. It should face open side rearword to catch the foreword air movement when at speed.
6. If you have headers they add heat like a furnace and should be ceramic coated and/or wrapped.

Hope this helps

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solotwo
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Report this Post07-27-2014 09:20 PM Click Here to See the Profile for solotwoSend a Private Message to solotwoEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Arns85GT:

there are a few ways to lower the temps.

1. run a slightly cooler thermostat. I run a 160 on my v8. I ran a 180 on my v6
2. Buy a 3 core aluminum rad. This is a big one.
3. Wrap your exhaust manifolds and particularly your cross over if you have one.
4. If those don't work, add an oil cooler, and if you have an automatic, a tranny cooler too.
5. Add a vent to your deck. It should face open side rearword to catch the foreword air movement when at speed.
6. If you have headers they add heat like a furnace and should be ceramic coated and/or wrapped.
Hope this helps



The PO of my car was running 180 thermostat. Engine is stock other than erg removed. It was running rich. I installed a 195 gas mileage improved by 2-3 mpg and it still is just as hot as before.

[This message has been edited by solotwo (edited 07-27-2014).]

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MadMark
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Report this Post07-27-2014 10:31 PM Click Here to See the Profile for MadMarkClick Here to Email MadMarkSend a Private Message to MadMarkEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by solotwo:


The PO of my car was running 180 thermostat. Engine is stock other than erg removed. It was running rich. I installed a 195 gas mileage improved by 2-3 mpg and it still is just as hot as before.



I am running a 180* thermostat too. I really don't have problems with my engine overheating, most of the time it stays right at 180*. Maybe I will try the 195* thermostat to see if it improves my gas mileage.
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solotwo
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Report this Post07-27-2014 10:37 PM Click Here to See the Profile for solotwoSend a Private Message to solotwoEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by MadMark:


I am running a 180* thermostat too. I really don't have problems with my engine overheating, most of the time it stays right at 180*. Maybe I will try the 195* thermostat to see if it improves my gas mileage.


Temp is now in normal range and no over heating issues at all. Just darned warm in the trunk because PO installed the exhaust right next to the trunk.
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Darth Fiero
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Report this Post07-28-2014 02:18 PM Click Here to See the Profile for Darth FieroClick Here to visit Darth Fiero's HomePageClick Here to Email Darth FieroSend a Private Message to Darth FieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
I have a magnaflow muffler (single in, single out) on my own Turbo 3800 Fiero. The trunk does NOT get abnormally hot - certainly not enough to melt the carpet or folding chairs I store in there. The trunk wall near the muffler does get warm on long drives, but not enough to melt even thin plastic grocery bags. I think the highest temp I ever measured in my trunk was 120 deg F or so.

I still have the factory heat shield that installs between the muffler and trunk in place and also still have the factory insulation pad installed between the carpet and trunk sheet metal wall. There is at least a 3/8" air gap between the outer heat shield and muffler at the closest point and there is still the factory air gap between the heat shield and trunk sheet metal wall. I also have the exhaust pipe between the turbo and muffler wrapped with header wrap, but the muffler itself is not wrapped in anything.

Having the proper air gaps and heat shield present are essential for preventing heat transfer to the trunk. If you have done anything to reduce or eliminate the air gaps, it will cause problems. Removal of the heat shield completely will also certainly cause problems.

-ryan

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OVERKILL IS UNDERRATED

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[This message has been edited by Darth Fiero (edited 07-28-2014).]

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fieroguru
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Report this Post07-28-2014 04:06 PM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
Like Ryan said, properly placed metal heat shields can work wonders for keeping specific items protected from excessive heat.

Here is the heat shield I tack welded to my magnaflow muffler (within 1/2" of trunk wall in this area):


Here is one I fabbed up to keep the heat off the A/C lines:



I can share other pictures of heat shields off cats, resonators, pipes and other portions of the exhaust to protect shift cables, CV boots, starters, etc...

They are simple to make, last for a long time, don't subject the pipes to higher temps, or prolong moisture exposure.
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solotwo
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Report this Post07-28-2014 04:13 PM Click Here to See the Profile for solotwoSend a Private Message to solotwoEdit/Delete MessageReply w/QuoteDirect Link to This Post
That's nice if you have a welder and all that nice fab equipment. I wished there was a 1/2 clearance.

[This message has been edited by solotwo (edited 07-28-2014).]

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Report this Post07-28-2014 04:17 PM Click Here to See the Profile for solotwoSend a Private Message to solotwoEdit/Delete MessageReply w/QuoteDirect Link to This Post

solotwo

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quote
Originally posted by Darth Fiero:

I have a magnaflow muffler (single in, single out) on my own Turbo 3800 Fiero. The trunk does NOT get abnormally hot - certainly not enough to melt the carpet or folding chairs I store in there. The trunk wall near the muffler does get warm on long drives, but not enough to melt even thin plastic grocery bags. I think the highest temp I ever measured in my trunk was 120 deg F or so.

I still have the factory heat shield that installs between the muffler and trunk in place and also still have the factory insulation pad installed between the carpet and trunk sheet metal wall. There is at least a 3/8" air gap between the outer heat shield and muffler at the closest point and there is still the factory air gap between the heat shield and trunk sheet metal wall. I also have the exhaust pipe between the turbo and muffler wrapped with header wrap, but the muffler itself is not wrapped in anything.

Having the proper air gaps and heat shield present are essential for preventing heat transfer to the trunk. If you have done anything to reduce or eliminate the air gaps, it will cause problems. Removal of the heat shield completely will also certainly cause problems.

-ryan


My car didn't have heat shields. Doesn't have room. PO did all of it
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solotwo
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Report this Post07-28-2014 04:18 PM Click Here to See the Profile for solotwoSend a Private Message to solotwoEdit/Delete MessageReply w/QuoteDirect Link to This Post

solotwo

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quote
Originally posted by Steve25:

"If you fix your car with something from Home Depot, you might be a Redneck".

A ceramic floor tile or two hung on the engine side of the firewall or trunk wall makes an excellent isolator. Like the Space Shuttle.



Sounds like a great idea to try.
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Darth Fiero
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Report this Post07-28-2014 06:01 PM Click Here to See the Profile for Darth FieroClick Here to visit Darth Fiero's HomePageClick Here to Email Darth FieroSend a Private Message to Darth FieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
You need to make sure you have an air gap between whatever you hang between the trunk wall and exhaust part. If you install any shield material directly onto the trunk wall (touching it), it isn't going to be very effective. The air gap is essential.

Ceramic tiles will conduct heat. Ever heard of bathroom floor heating with ceramic tiles over it?

[This message has been edited by Darth Fiero (edited 07-28-2014).]

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Report this Post07-29-2014 09:56 AM Click Here to See the Profile for 2.5Send a Private Message to 2.5Edit/Delete MessageReply w/QuoteDirect Link to This Post
Some ready made stuff:

http://www.jegs.com/webapp/...rchTerm=muffler+heat

http://www.summitracing.com...yword=muffler%20heat

[This message has been edited by 2.5 (edited 07-29-2014).]

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Curtisk1060
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Report this Post07-29-2014 11:26 AM Click Here to See the Profile for Curtisk1060Click Here to Email Curtisk1060Send a Private Message to Curtisk1060Edit/Delete MessageReply w/QuoteDirect Link to This Post
Ryan and others: When I finished my installation, I felt like I had about 3/8" to 1/2" of clearance between the inlet pipe/ top of muffler and the trunk. Once I found the melted trunk carpet, I massaged the trunk area to give it more room but the heat was still very high. I understand the need for the air gap, but I don't think there is a good path of air flowing under the car to keep things cool. Currently, the boiler insulation is working OK, but I may address it further this winter. I am still investigating maybe piping a cooling duct from my passenger side IMSA panel area just in front of my rear wheel via a small 4 inch fan to just above my inlet exhaust pipe so that it forces cooling air across the pipes at all times. Curtis
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Darth Fiero
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Report this Post07-29-2014 03:00 PM Click Here to See the Profile for Darth FieroClick Here to visit Darth Fiero's HomePageClick Here to Email Darth FieroSend a Private Message to Darth FieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Curtisk1060:

Ryan and others: When I finished my installation, I felt like I had about 3/8" to 1/2" of clearance between the inlet pipe/ top of muffler and the trunk. Once I found the melted trunk carpet, I massaged the trunk area to give it more room but the heat was still very high. I understand the need for the air gap, but I don't think there is a good path of air flowing under the car to keep things cool. Currently, the boiler insulation is working OK, but I may address it further this winter. I am still investigating maybe piping a cooling duct from my passenger side IMSA panel area just in front of my rear wheel via a small 4 inch fan to just above my inlet exhaust pipe so that it forces cooling air across the pipes at all times. Curtis


Having ONLY an air gap by itself (with no shield) is not enough. You need a "shield" in between the object radiating heat and the trunk wall. And that "shield", be it a simple piece of thin metal or ceramic tile or whatever, must also have air gaps between it and the trunk wall as well as between it and the heat source. The job of the heat shield is to stop the flow of radiant heat from being transferred thru it.

YOU NEED TO REINSTALL A HEAT SHIELD WITH AIR GAPS ON BOTH SIDES OF IT TO CURE YOUR ISSUE. Simply applying some kind of hi-temp insulating liner to the trunk wall with no air gap is not going to be as effective as reinstalling something like the factory heat shield.
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solotwo
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Report this Post07-29-2014 03:14 PM Click Here to See the Profile for solotwoSend a Private Message to solotwoEdit/Delete MessageReply w/QuoteDirect Link to This Post
In my case the car didn't come with it. PO kept it or thru it away.
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Darth Fiero
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Report this Post07-29-2014 03:55 PM Click Here to See the Profile for Darth FieroClick Here to visit Darth Fiero's HomePageClick Here to Email Darth FieroSend a Private Message to Darth FieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by solotwo:

In my case the car didn't come with it. PO kept it or thru it away.


Understand your situation. But you're going to have to either find (buy a used one) and install it, or make a new one from some thin stainless sheet metal or some other suitable hi-temperature material.

I certainly don't think buying and installing a thin insulation pad directly to the trunk wall without some kind of a shield with air gaps is going to do you much good.
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Report this Post07-29-2014 04:28 PM Click Here to See the Profile for solotwoSend a Private Message to solotwoEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Darth Fiero:


Understand your situation. But you're going to have to either find (buy a used one) and install it, or make a new one from some thin stainless sheet metal or some other suitable hi-temperature material.

I certainly don't think buying and installing a thin insulation pad directly to the trunk wall without some kind of a shield with air gaps is going to do you much good.

I have to check. Not much room. I doubt there is 1/2".

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Report this Post07-29-2014 04:38 PM Click Here to See the Profile for 2.5Send a Private Message to 2.5Edit/Delete MessageReply w/QuoteDirect Link to This Post
At $116 those muffler wraps must work like magic?

http://www.summitracing.com/parts/the-16800

[This message has been edited by 2.5 (edited 07-29-2014).]

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Report this Post07-29-2014 09:46 PM Click Here to See the Profile for solotwoSend a Private Message to solotwoEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by 2.5:

At $116 those muffler wraps must work like magic?

http://www.summitracing.com/parts/the-16800






Lets hope so as I plan on doing that along with other stuff.
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Darth Fiero
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Report this Post07-30-2014 11:13 AM Click Here to See the Profile for Darth FieroClick Here to visit Darth Fiero's HomePageClick Here to Email Darth FieroSend a Private Message to Darth FieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by 2.5:

At $116 those muffler wraps must work like magic?

http://www.summitracing.com/parts/the-16800





I'm sure the muffler wrap will help but I don't know if it will be as effective as a proper heat shield with air gaps. Depends on how well it can insulate/block the radiant heat.
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solotwo
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Report this Post07-31-2014 04:26 PM Click Here to See the Profile for solotwoSend a Private Message to solotwoEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Darth Fiero:


I'm sure the muffler wrap will help but I don't know if it will be as effective as a proper heat shield with air gaps. Depends on how well it can insulate/block the radiant heat.

Also looking to use it for sound deading.
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Darth Fiero
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Report this Post07-31-2014 05:21 PM Click Here to See the Profile for Darth FieroClick Here to visit Darth Fiero's HomePageClick Here to Email Darth FieroSend a Private Message to Darth FieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by solotwo:

Also looking to use it for sound deading.


A muffler wrap such as the one noted a few posts earlier probably will not be a significant sound deadener. If you are looking at keeping noise out of the passenger cabin, you're probably going to need to install a lot of dynomat behind the seats on the firewall and possible elsewhere in the car. Vibrant makes a resonator (looks like a mini muffler) that is only slightly bigger than a catalytic converter and it is pretty effective at reducing the amount of exhaust noise (I would say it is more effective than what a catalytic converter alone would do).
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Report this Post07-31-2014 08:46 PM Click Here to See the Profile for MadMarkClick Here to Email MadMarkSend a Private Message to MadMarkEdit/Delete MessageReply w/QuoteDirect Link to This Post
When I had my exhaust wrapped this last winter, I did notice a difference in the tone of the exhaust. It is much more pleasant now with the fiber glass wrapping on the manifolds and the muffler. I think the biggest change though was the wrapping of the front exhaust manifold.
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