testing exhaust headers
09-12-2005, 06:09 PM
#31
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Well, Im just curious as to what the performance of wrap is. This entire thread begs to avoid the question at all :/ From what ive read, Swain holds 50+% heat. If what tool says is accurate, then wrap only does 51+% heat retension. it could be more... mabey... mabey not. But if nothing else, wrap is definatley cheaper, because Swain cost 125-165$ and wrap only cost $40 with some elbow grease (link here). So, really thats enough for me... also, I probably save allot on shipping cause damn those headers are heavy.
ok,
-sd
ok,
-sd
09-12-2005, 06:12 PM
#32
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Ok..Jim... I will bite on this one.....What are the temp differances that you have?
Why would you do all this logging if you do not save the info.
I would like to see a pic of these wrapped headers you have
How often do you peplace the wrap..It has a very short life span.
Coatings last for a very long time as far as I can tell with the stuff I have had done.
Coatings reduce over 50%
I have spent a lot of time reducing heat on my car.I would be very interested in the facts that you have come up with.
Why would you do all this logging if you do not save the info.
I would like to see a pic of these wrapped headers you have
How often do you peplace the wrap..It has a very short life span.
Coatings last for a very long time as far as I can tell with the stuff I have had done.
Coatings reduce over 50%
I have spent a lot of time reducing heat on my car.I would be very interested in the facts that you have come up with.
09-12-2005, 06:16 PM
#33
Race Director
Originally Posted by special tool
I don't have them saved - I remember the results. I have made THOUSANDS of 944 related datalogs. You don't even have a logger, do you Geo?? Just another Rennlist speculator, I guess.
The difference is HUUUUGE - this topic of arguement is insane. The is no comparison between a DEI fabric wrap with a special spray coating and fairy dust magic coatings.
If you want to keep heat in the pipes - you wrap. Although - it won't be nearly as pretty as those fancy-pants, expensive coatings. So if you want a bling-bling home-boy set of pipes - get the coating.
By the way - to let you guys know how serious I am about REAL information - I have an aviation-grade EGT scanner, that tell me the temp of each individual pipe, or which one is hottest.
Who do you think knows the most about the inside of a 944 engine here????
The difference is HUUUUGE - this topic of arguement is insane. The is no comparison between a DEI fabric wrap with a special spray coating and fairy dust magic coatings.
If you want to keep heat in the pipes - you wrap. Although - it won't be nearly as pretty as those fancy-pants, expensive coatings. So if you want a bling-bling home-boy set of pipes - get the coating.
By the way - to let you guys know how serious I am about REAL information - I have an aviation-grade EGT scanner, that tell me the temp of each individual pipe, or which one is hottest.
Who do you think knows the most about the inside of a 944 engine here????
You say have have data, but when it's requested you don't have it. They you get very rude and obnoxious.
It's still my belief you didn't use Swain coatings since you describe them as pretty and bling-bling. White Lightning is certainly not pretty nor bling bling.
Since you remember the results, can you even give a before and after temp? Did you use the exact same parts or are you using different parts? You talk big, but when questioned you get rude and evade the questions.
You may be right, but you still haven't convinced me. All you say is "trust me" and get rude. As I siad, you certainly are a special tool.
09-12-2005, 06:18 PM
#34
Three Wheelin'
Originally Posted by unreal_news
Well, Im just curious as to what the performance of wrap is. This entire thread begs to avoid the question at all :/ From what ive read, Swain holds 50+% heat. If what tool says is accurate, then wrap only does 51+% heat retension. it could be more... mabey... mabey not. But if nothing else, wrap is definatley cheaper, because Swain cost 125-165$ and wrap only cost $40 with some elbow grease (link here). So, really thats enough for me... also, I probably save allot on shipping cause damn those headers are heavy.
ok,
-sd
ok,
-sd
09-12-2005, 06:22 PM
#35
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AznDrgn -> Yeah, my question above hasnt been answered 
* from above *
also, what special coating is needed, is it a hardner for the wrap, or an additional thermal type spray?
* from above *
also, what special coating is needed, is it a hardner for the wrap, or an additional thermal type spray?
09-12-2005, 06:25 PM
#36
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well, ive got more info from the thread below than anywhere around here so far... you guys should check it out...
http://fsae.com/groupee/forums/a/tpc.../r/72910784721
http://fsae.com/groupee/forums/a/tpc.../r/72910784721
09-12-2005, 06:26 PM
#37
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Originally Posted by Geo
Compared with Swain it will not do much. Most such coatings are off-the-shelf and simply ceramic paint. If you look carefully, you will see they only talk about what kind of temps it can withstand but nothing about any actual reductions in temps. Swain's coating is a true thermal barrier.
Most header companies use this type of coating because it looks pretty and will last longer than paint (which pretty much won't last at all on an uncoated header). Swain's coating can be painted and I did just that with my high output 2 liter SR20DE (Nissan) header. Never had a problem with the paint.
Most header companies use this type of coating because it looks pretty and will last longer than paint (which pretty much won't last at all on an uncoated header). Swain's coating can be painted and I did just that with my high output 2 liter SR20DE (Nissan) header. Never had a problem with the paint.
09-12-2005, 07:36 PM
#39
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I am pretty sure ST bought his laptop from the NASA auction just after Apollo 11. 
I asked him the same question when I had my engine out, about the ceramic coating. He had datalogged the stock header, then ceramic coated, then the stock header wrapped with the DEI stuff. He claims there was no noticeable difference between the stock header and the ceramic coating, but he gained over 100 RPM quicker spoolup with the DEI wrap.
I have no personal experience to back the claim up, but if ST says it, then it is true.
I asked him the same question when I had my engine out, about the ceramic coating. He had datalogged the stock header, then ceramic coated, then the stock header wrapped with the DEI stuff. He claims there was no noticeable difference between the stock header and the ceramic coating, but he gained over 100 RPM quicker spoolup with the DEI wrap.
I have no personal experience to back the claim up, but if ST says it, then it is true.
09-12-2005, 07:37 PM
#40
Race Director
Originally Posted by Mark-87-951
Well that link claims a 110 to 120 degree temp. drop in radiated heat. If that's true it seems to indicate more than just withstanding the heat, unless there is some clever marketing with the wording.
BTW, I am in no way associated with Swain or any other coatings company or any company that sells header wrap.
I will also freely admit I don't have the hard data on this. I'm also very open minded. If someone has data, that's great. But bullying, saying "I have datalogs" and then saying "I don't have them, but trust me" just isn't doing it for me.
I did notice something in the SAE link about F1 headers not being coated, but one also needs to remember they are using pretty high tech alloys for their headers. I believe they use Inconel. I admit I don't know the properties of Inconel, but I know it's used in very high heat, harsh environment applications. I don't know if F1 header temps are too high for coatings or if they materials make them unnecessary or if their testing shows wraps and coatings to be worthless. One would think if coatings would help they would be used in F1. I just don't know the details of that and have never seen it discussed in Racecar Engineering.
09-12-2005, 07:40 PM
#41
Race Director
Originally Posted by tedwright
I asked him the same question when I had my engine out, about the ceramic coating. He had datalogged the stock header, then ceramic coated, then the stock header wrapped with the DEI stuff. He claims there was no noticeable difference between the stock header and the ceramic coating, but he gained over 100 RPM quicker spoolup with the DEI wrap.
09-12-2005, 08:17 PM
#44
Burning Brakes
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Originally Posted by Geo
I am not claiming that Jethot products don't block any heat. I will look a little more at that link later, but I have to ask what the temp drop was from? If it's from 900+ degrees, I'm hardly impressed.
BTW, I am in no way associated with Swain or any other coatings company or any company that sells header wrap.
I will also freely admit I don't have the hard data on this. I'm also very open minded. If someone has data, that's great. But bullying, saying "I have datalogs" and then saying "I don't have them, but trust me" just isn't doing it for me.
I did notice something in the SAE link about F1 headers not being coated, but one also needs to remember they are using pretty high tech alloys for their headers. I believe they use Inconel. I admit I don't know the properties of Inconel, but I know it's used in very high heat, harsh environment applications. I don't know if F1 header temps are too high for coatings or if they materials make them unnecessary or if their testing shows wraps and coatings to be worthless. One would think if coatings would help they would be used in F1. I just don't know the details of that and have never seen it discussed in Racecar Engineering.
BTW, I am in no way associated with Swain or any other coatings company or any company that sells header wrap.
I will also freely admit I don't have the hard data on this. I'm also very open minded. If someone has data, that's great. But bullying, saying "I have datalogs" and then saying "I don't have them, but trust me" just isn't doing it for me.
I did notice something in the SAE link about F1 headers not being coated, but one also needs to remember they are using pretty high tech alloys for their headers. I believe they use Inconel. I admit I don't know the properties of Inconel, but I know it's used in very high heat, harsh environment applications. I don't know if F1 header temps are too high for coatings or if they materials make them unnecessary or if their testing shows wraps and coatings to be worthless. One would think if coatings would help they would be used in F1. I just don't know the details of that and have never seen it discussed in Racecar Engineering.
09-12-2005, 08:35 PM
#45
or Sam O
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From a engineering standpoint, heat transfer(q) = -k*A*(dT/dr) for conduction. You have conduction when heat is transferred between a temp gradient in a solid. Very generally speaking, two things matter here. k and the outsider diameter of the wrap or coating.
k is the thermal resistivity of an object, basically how much it resists heat transfer. The lower the number the better it resists heat transfer. Fiberglass is a better insulater or has a lower k than most ceramics. However, a wrap has gaps where can enter where a coating is normally uniform.
Secondly the outside diamter mattters beacause there is a limit to the amount of insulation that can be used before you actually help cooling. Why? because you increase the surface area exposed to air when you wrap or coat it more. Think cpu heatsink.
This is all very general and alot of math backs it up, I can produce it you want.
Anyways, without specefic ceramic coating makeup, thickness of coating or wrap, wrap makeup, diameter of pipe and pipe material no one can claim anything. The only other way is through experimentation with hard data and a control group.
k is the thermal resistivity of an object, basically how much it resists heat transfer. The lower the number the better it resists heat transfer. Fiberglass is a better insulater or has a lower k than most ceramics. However, a wrap has gaps where can enter where a coating is normally uniform.
Secondly the outside diamter mattters beacause there is a limit to the amount of insulation that can be used before you actually help cooling. Why? because you increase the surface area exposed to air when you wrap or coat it more. Think cpu heatsink.
This is all very general and alot of math backs it up, I can produce it you want.
Anyways, without specefic ceramic coating makeup, thickness of coating or wrap, wrap makeup, diameter of pipe and pipe material no one can claim anything. The only other way is through experimentation with hard data and a control group.