Has anyone used exhaust wrap on their downpipe? I heard that it does a good job keeping the heat in the pipe and thus helped to lower the underhood temps. I also heard that if you get oil or anything hot on the wrap it could catch on fire. Anyone have input? Thanks.
Exhaust Wrap
- Thread starter 2112
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BRAD_PADGETT
Well-Known Member
- Joined
- Jan 22, 2004
I am speaking from a common sense point. None of the GM Turbo 3.8 cars had it why question the engineering 20 years later? I did add extra heat shielding for my wires by the turbo. My 2 cents. Brad
Lee Thompson
New Member
- Joined
- May 24, 2001
I read an article
A few years back when I was into DPs. The article stated that if used on mild steel tubing ( wrapped) it would burn the carbon out and leave it brittle thus greatly shortening the life of the tube.
A few years back when I was into DPs. The article stated that if used on mild steel tubing ( wrapped) it would burn the carbon out and leave it brittle thus greatly shortening the life of the tube.
I have no idea as to whether wraps are a good or bad idea, but saying no based just on the fact that the factory didn't do it is faulty logic. The time it would take to wrap a pipe on an assembly line would probably have prohibited it, even if it had been a good idea. Plus, if we used that logic, the factory never installed ceramic coated headers or pipes, didnt install alcohol injection (even after looking into it and experimenting with it) didn't install 2.5 or 3" downpipes, or any of the multitude of other performance upgrades we do everyday, because its a really good idea. Not a personal attack or flame or anything brad, just putting in my thoughts. Happy motoring!!!
BRAD_PADGETT
Well-Known Member
- Joined
- Jan 22, 2004
I would not spend a single penny wrapping the downpipe. Spend your money cooling the engine-FBODY radiator, dual ramchargers, Caspers electric fan conversion and an oil cooler. My 2 cents. Brad
just my thoughts
There is no coating out there that can do anywhere close to a good a job keeping the heat in the pipes like the thermal wrap can. Right after shut down, I can pop my hood and grap my uppipe with my bare hands and hold onto it. I can touch it for a few seconds while its running, but thats getting pretty silly. Lets see anyone do that with a coating, or the steel braid stuff the factory installed. Yes, there is potentially more chances of a fire hazard, but thats something I'm not concerned with on my car. My reasoning for no concern has no backing from a safety standpoint, so I won't bother explaining.
Rust could definetly be a issue, if: it gets water on it. My car is not drove in the rain, I don't get the wrap wet when I wash it, I keep the car in a insulated garage that is sealed very well, therefore, moisture doesn't build up in the garage, which can be a big problem here in the midwest, especially during the spring months when the humidity and temp is just right, causing cold metal surfaces to "sweat". Repeated short trips can cause moisture build up on exhaust also (a no brainer, this hurts the inside and outside on the exhaust of any auto) I do know what the before and after results are for the "to wrap and not to wrap" just from seeing the differance on my car, and the results are dramatic. I'm not trying to prove or sell anything here, just want to throw this out there for somebody who might be in the same situation as me.
However, saying that, I'll go ahead and add that when I get my upgraded down-pipe, I will not wrap it, I'll get it coated, and keep my up-pipe wrapped. It only takes a few minutes to pull the uppipe. So, for extra peace of mind, I'll cut the wrap off once a year and inspect it for corrosion, then re-wrap.
There is no coating out there that can do anywhere close to a good a job keeping the heat in the pipes like the thermal wrap can. Right after shut down, I can pop my hood and grap my uppipe with my bare hands and hold onto it. I can touch it for a few seconds while its running, but thats getting pretty silly. Lets see anyone do that with a coating, or the steel braid stuff the factory installed. Yes, there is potentially more chances of a fire hazard, but thats something I'm not concerned with on my car. My reasoning for no concern has no backing from a safety standpoint, so I won't bother explaining.
Rust could definetly be a issue, if: it gets water on it. My car is not drove in the rain, I don't get the wrap wet when I wash it, I keep the car in a insulated garage that is sealed very well, therefore, moisture doesn't build up in the garage, which can be a big problem here in the midwest, especially during the spring months when the humidity and temp is just right, causing cold metal surfaces to "sweat". Repeated short trips can cause moisture build up on exhaust also (a no brainer, this hurts the inside and outside on the exhaust of any auto) I do know what the before and after results are for the "to wrap and not to wrap" just from seeing the differance on my car, and the results are dramatic. I'm not trying to prove or sell anything here, just want to throw this out there for somebody who might be in the same situation as me.
However, saying that, I'll go ahead and add that when I get my upgraded down-pipe, I will not wrap it, I'll get it coated, and keep my up-pipe wrapped. It only takes a few minutes to pull the uppipe. So, for extra peace of mind, I'll cut the wrap off once a year and inspect it for corrosion, then re-wrap.
OK, so you live somewhere with no humidity at all ever. Great, no moisture. You run your car in air, you get the effects of humidity. Have you ever touched a thermal barrier coated exhaust housing after a 27 psi blast? I have. If you have ever experienced the hot air blast when opening your hood, you will be able to appreciate the benefit of a thermal barrier coating. No more hot air blast, no more burning yourself adjusting the wastegate. When they coat your parts, they coat the inside and outside. Does your wrap protect the inside of your pipe too? No. Your pipe sweats, the wrap keeps it in, and the inside gets attacked as it normally does. In the end of the day, a thermal barrier coating will extend the life of your part at least 10 fold, and will also give you the benefit of heat radiation reduction.
Jerryl
Tall Unvaccinated Chinese Guy
- Joined
- Dec 14, 2004
Water induces corrosion, whether inside or outside. One more variable, just for fun: What if the parts are stainless, like most aftermarket up-pies? 
Heat is also a good thing as it keeps the gas velocity high. So the barrier reduces “under hood temps”, as well as attempts to maintain the “gas velocity”. Always thought that the X-over should be one of the main pipes to be wrapped in a barrier of some type form a velocity point of view.
Heat is also a good thing as it keeps the gas velocity high. So the barrier reduces “under hood temps”, as well as attempts to maintain the “gas velocity”. Always thought that the X-over should be one of the main pipes to be wrapped in a barrier of some type form a velocity point of view.
I think the ultimate would be stainless with a coating. Stainless wrapped could work out ok, but I'm not sure! I think wrapping a crossover would be the most dangerous setup because of the ease of oil getting on there and lighting up. I like the way ceramic looks too, so I'm a little biased I'm actually picking up a bunch of parts from my coater today so maybe I'll post up some pics later. Oh, and I didn't mean to sound like a jerk in my previous post, that's just how it came out!
I'm actually picking up a bunch of parts from my coater today so maybe I'll post up some pics later. Oh, and I didn't mean to sound like a jerk in my previous post, that's just how it came out!I agree about wrap on a crossover, that would definetely make me concerned about fire hazzard being rear main and a number of other leaks will most probably leak right onto it.
Unfortunetly, we can't all sit together at the dinner table and discuss our knowledge/exp. in person. I don't care how nice or jerky anybody comes across on this message board. I'm just thankful their sharing their knowledge with me. I'm here to learn, and, to post my results and thoughts (once in a while).
Having said that, I confess I haven't done any research on the exhaust wrap, I've not been concerned about it. But now another thought has came into my tiny brain and I'm starting to wonder what the heck am I missing here? Lemme explain
I know for a fact my 84 GN has been in the St. Louis area since new. I also know that it spent most of its life sitting outside (in the rain/snow etc), and has also sat for a few periods of time. I know that the car was never cared for anywhere as good as I care for it now. My car still had the factory up-pipe and down-pipe white insulation wrapped with the factory steel braid hose that had the welded clamps on both ends. I had removed it from the up-pipe to repair a leak (was the result of a poor factory weld evidently). I had removed the dp to install headers, and removed the factory wrap then. Both pipes where in excellent shape. No internal corrosion out of the ordinary, and no external corrosion where the factory wrap/insulation had been (for 22 years). (I don't claim to be a expert on corrosion, but I spend a good deal of time at my job inspecting for corrosion on aircraft, so I know a little bit I suppose). Anyways, So... where does wrapping these parts become an issue? I refuse to believe I'm just lucky. Anybody today looking for a hot air turbo car can find one pretty easy. Whether its ebay, these buick boards, or any # of auto for sale sights, and almost everyone of them that I see, still have the factory white insulation wrap covered with the steel braided hose. My point is, It doesn't exactly look like these "wrapped" exhaust parts are failing after 20+years. I realise I can't see the inside of the pipe when I'm looking at a picture of someone else's engine compt. But still, going off mine, I doubt theirs is much differant than mine. What am I missing here? I'll do a little research. Maybe I can find some postings where people have pictures and justification to say "Look, yes, Header wrap installed on exhaust parts do indeed cause failure!"
Is the factory metal used in our up-pipe,dp, crossover...a much higher grade and quality than some of the aftermarket stuff? Therefore maybe giving some people some bad experiences with header wrap? (I know our crossovers where double layered, making them pretty heavy, I think our dp's are too? I don't think the uppipes are, but don't know)
Any comments would be appreciated. (keep in mind I'm still pretty new to these cars, at least in the depth that I am involved with them now, I should say)
Unfortunetly, we can't all sit together at the dinner table and discuss our knowledge/exp. in person. I don't care how nice or jerky anybody comes across on this message board. I'm just thankful their sharing their knowledge with me. I'm here to learn, and, to post my results and thoughts (once in a while).
Having said that, I confess I haven't done any research on the exhaust wrap, I've not been concerned about it. But now another thought has came into my tiny brain and I'm starting to wonder what the heck am I missing here? Lemme explain
I know for a fact my 84 GN has been in the St. Louis area since new. I also know that it spent most of its life sitting outside (in the rain/snow etc), and has also sat for a few periods of time. I know that the car was never cared for anywhere as good as I care for it now. My car still had the factory up-pipe and down-pipe white insulation wrapped with the factory steel braid hose that had the welded clamps on both ends. I had removed it from the up-pipe to repair a leak (was the result of a poor factory weld evidently). I had removed the dp to install headers, and removed the factory wrap then. Both pipes where in excellent shape. No internal corrosion out of the ordinary, and no external corrosion where the factory wrap/insulation had been (for 22 years). (I don't claim to be a expert on corrosion, but I spend a good deal of time at my job inspecting for corrosion on aircraft, so I know a little bit I suppose). Anyways, So... where does wrapping these parts become an issue? I refuse to believe I'm just lucky. Anybody today looking for a hot air turbo car can find one pretty easy. Whether its ebay, these buick boards, or any # of auto for sale sights, and almost everyone of them that I see, still have the factory white insulation wrap covered with the steel braided hose. My point is, It doesn't exactly look like these "wrapped" exhaust parts are failing after 20+years. I realise I can't see the inside of the pipe when I'm looking at a picture of someone else's engine compt. But still, going off mine, I doubt theirs is much differant than mine. What am I missing here? I'll do a little research. Maybe I can find some postings where people have pictures and justification to say "Look, yes, Header wrap installed on exhaust parts do indeed cause failure!"
Is the factory metal used in our up-pipe,dp, crossover...a much higher grade and quality than some of the aftermarket stuff? Therefore maybe giving some people some bad experiences with header wrap? (I know our crossovers where double layered, making them pretty heavy, I think our dp's are too? I don't think the uppipes are, but don't know)
Any comments would be appreciated. (keep in mind I'm still pretty new to these cars, at least in the depth that I am involved with them now, I should say)
Jerryl
Tall Unvaccinated Chinese Guy
- Joined
- Dec 14, 2004
Clarification:
I would never wrap the X-over or, advocate anyone does for all the safety reasons mentioned. I was thinking more along the lines of ………. Remember the “old” chrome plated motorcycle headers? The ones that had a double wall? (That is what I was thinking)
Anyway ………. I have a few other thoughts as well, like, the restriction in the X-over, the creases (Not ripples) in bend non-mandrel bend tubing …… like the "D" ports everyone now knows work, etc ...............
Possibly a similar effect as "shortening the long side" ......... (back to the subject)
I would never wrap the X-over or, advocate anyone does for all the safety reasons mentioned. I was thinking more along the lines of ………. Remember the “old” chrome plated motorcycle headers? The ones that had a double wall? (That is what I was thinking)
Anyway ………. I have a few other thoughts as well, like, the restriction in the X-over, the creases (Not ripples) in bend non-mandrel bend tubing …… like the "D" ports everyone now knows work, etc ...............
Possibly a similar effect as "shortening the long side" ......... (back to the subject)
Jerryl
Tall Unvaccinated Chinese Guy
- Joined
- Dec 14, 2004
I am getting off the original subject but ........ if you look at the stock X-over, where the flanges are located is a "swaged end" from clamping (??), and the diameter is noticeably smaller.
nice parts Chevymd, did you do the uppipe too?
Jerryl, Do you think maybe they didn't really consider the smaller diameter at the ends a big deal since its only taking care of the 3 cylinders? I know its definetly going to choke it a bit, but so does the stock dp, lol. Also, doesn't the postons X-over tube eliminate that? I've got the postons crossover tube, but haven' mounted it yet, or really looked at it closely. I bought it because I thought I had a exhaust leak with my stock one because I took it to the muffler shop and stretched it a half inch to fit up with the poston headers. Found out when I removed it to change the pan gasket, it was my downpipe to test pipe connection leaking.
Jerryl, Do you think maybe they didn't really consider the smaller diameter at the ends a big deal since its only taking care of the 3 cylinders? I know its definetly going to choke it a bit, but so does the stock dp, lol. Also, doesn't the postons X-over tube eliminate that? I've got the postons crossover tube, but haven' mounted it yet, or really looked at it closely. I bought it because I thought I had a exhaust leak with my stock one because I took it to the muffler shop and stretched it a half inch to fit up with the poston headers. Found out when I removed it to change the pan gasket, it was my downpipe to test pipe connection leaking.
I have a front mount and haven't done those pipes yet, I'm going to see how the stuff I just did looks when it's on there, and if I wanna make them match I'll get them done. It should be a big improvement aesthetically from its previous condition. The dp is stainless and the turbo is new, so it didn't look bad per se, but I was worried about the exhaust housing when it rusted. It was cheap to do too, so I figured why not!
