I've searched and searched and searched and have never been able to find before and after testing of heat wraps, turbo blankets and heat radiating tape with actual numbers to back up any claims. I'm not being paid by anyone but just wanted to see if any of this stuff works and if it does, how can I use it to not only lower under hood temperatures but to also lower intake air temperatures.

I purchased DEI's new Titanium Heat Wrap to use on my turbo manifold, waste gate dump tube and down pipe. I purchased a turbo blanket designed to fit on a T3 turbo. I also purchased DEI's Reflect A Gold heat tape to apply to my intercooler and piping. Lastly I purchased several Wireless Digital Thermometers with probes to gather and record my temps.

I'm starting off by logging the under hood temperatures at idle, at a steady average speed of 60 mph and a WOT pull to show any differences. I'll be placing probes between the driver's side headlight and turbo manifold, radiator fan and engine, and the intake manifold and firewall. All probes will be measuring air temperature only and not surface temperature. Probes will be arranged to not come in contact with anything but air.

The total amount of data that I'll be recording during every test is:
1. ambient air temp
2. probe temp
3. engine coolant temp (ECT)
4. oil temp
5. intake air temp (IAT)

I'll be conducting the Overall Under Hood temps in the following order:

1. No wraps, blankets or tape (record temps idle/60mph/WOT)
2. Wrap turbo manifold (record temps idle/60mph/WOT)
3. Apply turbo blanket (record temps idle/60mph/WOT)
4. Wrap down pipe (record temps idle/60mph/WOT)

After recording all of the above data, I'll then start taking temperatures of the inside of my intercooler charge piping. The probes will be inserted in the following locations:

1. turbo inlet without filter or tube
2. turbo outlet
3. intercooler inlet
4. intercooler outlet
5. throttle body inlet

Depending on if the temperatures gathered on the inside of the charge piping is less than the temperatures in the engine bay, reflective heat tape will be applied and further testing will be conducted to note any changes. The goal would be to reduce pressure drop and intake air temps. The ambient, probe, ECT, oil, and IAT temps will be recorded during this testing as well to note any changes.

Test Subject:



Purchased Items:







The other day I started recording temps under the hood (hood closed) at idle with no wraps or anything at all to gather my base line readings. The ambient temperature that day was 54 degrees. Probes were placed in the locations described above and the following was recorded. Fan Eng. means how many times the radiator fan kicked on.



The first thing that I noticed with the probe between the headlight and turbo manifold was that every time the radiator fan would kick on the under hood temperature would rise very quickly. After the fan would cut off the temp would lower a few degrees but never as low as it was before. The fan would then kick on again and the temp would rise again and would usually rise even higher then what it was before.



Now after placing the probe between the radiator and engine I noticed something a little different. The temperatures were still rising drastically when the radiator fan kicked on, but after rising the temperature would then go down a few degrees (radiator fan still running). I would see numbers like this:

157 degrees, fan kicks on temp rises to 169 degrees and then drops to 167 degrees before fan cuts off.



Now after placing the probe behind the intake manifold the results were much like the ones taken between the headlight and manifold except much higher. The first thing that I noticed was the higher temperatures, in fact they were the highest temperatures in the engine bay! Of course when the fan kicked on the temperatures would rise every time except the temps would just peak out and not fall back down. My early theory was that maybe the heat is trapped between the intake manifold and firewall, causing the higher temps.

Hypothesis: I can see now how effective those custom setups that you see on S2000's can be. The setup I'm talking about is when custom fabricators direct all the air that passes through the bumper, intercooler and radiator and channel it up and out of the hood, keeping that heat out of the engine bay. I was seeing temperatures increased as much as 12 degrees when the radiator fan kicked on, this may not be a lot, but when your boosted and IAT's are everything that 12 degrees means a lot!! Especially when the highest temps recorded were right next to the intake manifold!! I'm sure if someone could fabricate something similar to what you see on S2000's on a Civic/Integra it would help. Let me know what you guys think and feel free to give me ideas on other ways to do this and stay tuned for more test!!

 

So next after gathering the Pre Wrap data at idle I went for a drive. Now I know I could have taken the temps and various speeds, as I'm sure it would have reflected different temps I decided to go with an average speed of 60 mph (plus I didn't want to get pulled over) lol. This part of the test was straight forward, I took temps in the same location as last time; between headlight and turbo manifold, between radiator and engine and between the intake manifold and fire wall.

During this test I noticed a considerable drop in temperature in the engine bay with an average temperature reduction of 73 degrees. Here are my graphs below.







Stay tuned for more test! Next test will be after the heat wrap is applied to the turbo manifold.

 

In for more results. Can't wait to see how everything together effects the temps.

 

Thanks stay tuned the next one will be after the heat wrap was applied to the turbo manifold

 

Very interesting that the temp. was that much higher behind the intake manifold, maybe the rubber seals on the hood block the heat in there, instead of passing out over the windshield. lookin forward to further testing. Good job so far!

 

In for this! Always wondered how far you would have to go to bring under hood temps down significantly.

 

Now the third test that I did was noting the temperature differences after the heat wrap was applied. My turbo manifold was wrapped with DEI's new titanium heat wrap. I have a equal length manifold and all that was wrapped was the 4 runners and the tube running to my waste gate. Immediately a reduction in overall under hood temperatures were noticed (at idle). Another thing that was noticed was that the rate at which the under hood temperatures climbed were much slower then before (no wrap). For these comparisons I used the highest number recorded and the same amount of time was used to gather the results to try and keep the results as true as possible. Now on to the results:

Between headlight and turbo manifold:
Before Wrap:189 degrees
After Wrap:130 degrees
Reduction:59 degrees

Between Radiator and Engine:
Before Wrap:180 degrees
After Wrap:129 degrees
Reduction:51 degrees

Between Intake Manifold and Fire wall:
Before Wrap:202 degrees
After Wrap:133 degrees
Reduction:69 degrees (highest reduction yet!!









Hypothesis: Well for the most part it's pretty straight forward, however the major reduction behind the intake manifold has me thinking. Are the temps higher behind the intake manifold because it gets trapped between the intake and fire wall? Or is it because of the lack of air flow, because of aerodynamics? This is a question that I would like to find the answer to because judging by the results it has some bearing on IAT's. Now I would agree that most of the reason for high IAT's comes from the head heat soaking everything in it's path, but apparently the under hood temp influence has maybe been a little under rated? I don't know but the numbers don't lie. A reduction in IAT's was noted in all three places that temps were taken! The highest in IAT reduction was 14 degrees!! Now thats not a huge reduction, but when you boosted every little bit counts.

Performance Gains: I originally wasn't going to include this in the review but I kind of have to. After wrapping the exhaust and getting the idle temps I went for a little drive so that I could get the driving temps. Well it started raining and I didn't know if that would have skewed the results so I didn't record any data, however I did noticed a difference in my turbo spool times. Now I'm not saying that its a night and day difference but the reduction in spool time is noticeable. I pulled out of my neighborhood and gave it gas like I normally do, the car started pulling a little harder. I changed gears and tried it again to make sure that I wasn't imagining things. By the time I got to third gear I realized that I was imagining things and that the car was actually pulling harder. I wasn't able to record a datalog as I left my laptop at home. I will however record one when it's not raining. Stay tuned for more, next will be the 60 mph driving when its not raining.

 

I like this. Keep up the good work on the testing.

 

space your hood up and your temps will drop.

 

Thanks for the tip will do!!

 

thx

 

now this is a awesome thread! In for more results

 

Thanks I really appreciate it!!

 

awesome work so far. Like to see that log.

 

wouldn't that only happen when the car is at rest b/c while the car is in motion i don't see how cooler air would be able to get into the engine bay

 

I would think since heat rises any extra ways to let the heat escape would be a plus. I removed the rubber seals on my hood. Lets a good amount of heat out. Also my car never see's rain so I don't need the rubber seals.

 

Thanks a lot as soon as it's not raining I will definitely be able to data log and post it up.

 

I definitely understand where your coming from, but my theory (and this is only a theory until I test this) is cooler air is able to get inside of the engine bay while driving. I proved this earlier in my testing, the under hood temperatures dropped drastically so air has to be getting in there some how. Now if the back of the hood is tilted up, I would like to think that you would be giving that air under the hood somewhere to go, hence creating like a vacuum effect. Now again this is only a theory but hopefully soon this will be proven in one way or the other. I forgot all about the tilted hood debate and should have included that in this from the beginning lol.

 

You are correct, heat does rise and it also travels from the hottest point to the coldest point. Thats the reason why if my under hood temps are higher then the charge piping, reflect a gold will be applied to radiate that heat that is going to be attracted to it. Thanks for your responses. Will be a great learning thread for everyone hopefully.

 

I wonder how the DEI Titanium wrap would do versus a manifold coating like Full-Race and TheShodan offer on their products.

Maybe I'll have to test that when I get a chance.

 

Now that would be a good test, unfortunately I'm not going to be hot coating anything in the near future. So I'll leave that up to someone else.

 

I may have to convince my brother to let me use his car as a test mule.

Do you have any pictures of the probe placements for me to copy?

 

Good stuff, it is awesome of you to share this data!

 

Yes I do have pics, give me one sec and I'll post them up

 

Thanks, I'm hoping that this will end a lot of the debates about heat wrap and especially the reflective heat tape. It was also cool that I have the datalog capabilities to show what some of my sensors are showing. I was talking with JR and I'm going to be adding permanent air temp sensors along my charge piping to log how their influenced by the weather. I think this will be good as improvements can always be made as you go.