Flight Test

I was searching the used parts forum and came across this picture that showed a pair of turbocharger insulation blankets that came with a pair of intercoolers and scorpion intakes. They look like PTP turbo blankets, and I assume they are probably the ones for Porsche K24 turbos. Has anyone ever tried the blankets to lower the under hood temperatures?

Here is the picture from the sale add.

I think these are the blankets that might fit.

http://ptpturboblankets.com/Porsche-...ts-000526.html

Any thoughts or expierence out there?

Welwynnick

I'm convinced that many problems associated with the V12TT can be attributed to high under hood temps caused by the turbos. I never thought of adding turbo blankets though. I'm rather ignorant there unfortunately. I've seen lots of tuning shops sell them, and I appreciate the upsides, but I don't know about the downsides.

Presumably, by insulating the turbo, they increase its operating temperature. I guess that many people have done just that, and I'd sure like to know if they'd had faster turo failures as a consequence. Or not. Our turbos are water-cooled , so I'm sure that helps to protect them.

I rebuilt my turbos this summer, and I looked at lots of ways of improving the under-hood heat management:

I fabricated a couple of heat shields to cover the whole length of the coil packs, sitting just outboard of the existing heat shields. I stuck some temperature tape on the coil packs to see if that lowered their peak surface temps. The results aren't in yet.

I also wrapped the charge cooler lines in foil and fibreglass heat mats, to help insulate them from the turbos and reduce heat soak. I did the same to the IC's themselves, though I doubt that makes much difference.

I can monitor my IC coolant temperature from my pump controller, and it does stay cool. I turned down the target temperature from 30C to 25C yesterday, and sure enough it ran 5C cooler today.

The other thing I've done is replace all the ABC hoses in the engine compartment with compression-jointed removable hoses, and add reflective thermal insulation to those as well. I think that long term, that will probably be the biggest win.

I did consider adding metal plates to the underside of the pipes between the compressors and the IC's, but I couldn't afford the time

Of course, adding insulation to the turbos themselves may tackle the root cause of the problem, as long as the turbos themselves don't get too hot.

Nick

Edit: Well, I did a bit of research, and most people said there was no downside (on other makes of cards at least) just significantly reduced under-hood temperatures. However, many people seemed to be aware of the risk of cracking the turbine housing due to over-heating.

Flight Test

Howdy Nick,

I have long been contemplating insulating the intercoolers themselves since they seem to turn into interheaters sitting in the hot engine bay. I would be very interested to see what you came up with for insulating the intercoolers themselves. Do you have any pictures of your setup? Did you gather any data pre/post insulation?

I also want to insulate the metal intercooler coolant lines that run under the coil packs and above the exhaust manifolds. This seems like a very ineffective location to transfer coolant you want to keep cold.

Our thoughts are the same on thinking the underwood temps cause us a huge amount of grief on these machines.

F1BHP

I have the scorpion intakes which obviously suck hot air from under the hood however I am fitting some TTM style scoops to force more cool air into the engine bay along with a vented hood. The E class guys use the scoops but i havnt seen any on the V12's.
I probably won't get to try the setup out until mid Jan at Silverstone so at the moment i don't know if it will work however makes sence in my mind.
What do you guys think?
I don't like the idea of increasing the turbo temps. By insulating them they must get hotter as they will definitely benefit from cooling under the hood even if the temp Is high it will still be considerably cooler than the turbo housing.

Flight Test

Getting lower intake temperatures with the minimum intake restriction is our goal. There is a trade off between the incoming air tempurature and intake restriction. Turbo and supercharger efficiency drops off dramatically with even minimal intake restriction. In our case that is the convoluted stock air filter set up or your scorpion intakes, without real measured data I can't speculate where the dividing line is between getting cooler intake air temps from a stock type filter setup or your scorpion setup. Anything to provide you cooler intake temps with no extra restriction is a good thing.

I have only seen pictures of the TTM style scoops and it looks like they try to make use of the opening that is available, however flat plate non radiused intersections provides a less than optimal inlet shape. I do understand though it is difficult to fit an efficient radiused inlet when there is very little space available. Your vented hood opens up some interesting other options.

As for the turbo blankets the cast iron of the exhaust housings can more than withstand the slight increase in temperatures but the other components need to be investigated like the oil and coolant lines along with the seals. The added benefit of the increased temps are a larger volume of hot exhaust which has the possibility to reduce turbo spool up time and keep more energy and volume going over the turbine wheel. The lower under hood temps would sure seem to help your scorpion intake temps.

Welwynnick

There are lots of different ways to do thermal management under hood, and they need to make sure the protection measure addresses the right threat to performance and reliability:

infra-red radiation
conduction
convection

You have to consider both where the heat is coming from, and where it goes to. For example, I think the IC's problem is simply conduction from the surrounding hot air. Yes, they do cool themselves due to the circulating water, but we simply want to reduce the flow of incoming heat. Insulation or lagging should do that. I've got some pictures of what I've done, and I'll post them today.

The coil packs on the other hand, are a rather different problem. They're in line of sight of the turbos, so they're subject to infra-red radiation, and they DON'T cool themselves. Mercedes solution is to screw insulating covers to the exposed center sections. The insulation does have a reflective outer layer, but there's insulation in between, and they're in contact with the coil pack.

I don't think this is a good idea, as there's no air under the shield, and heat will conduct through to the coil. When manufacturers insulate exhaust systems, they normally use single skin metal shields that provide a barrier for IR radiation and convecting air. They provide no insulation at all, but they're very effective. The key thing is that air is able to flow past both sides of the shield, so temps are never allowed to build up.

I think that's what's needed for the coil packs, so I built a pair of ally shields that stand off the coil, allowing air to flow down both sides. It took a few goes, and mounting them is tricky, as there's not much room, but it help if the stock shield is removed. I fitted one, and left the other off, to see what difference they make. I put temperature tape on the coil packs, and I'll take the intakes back off soon & look for any difference between them. What I did notice on Sunday is that on my first long journey for nine months, it never misfired and threw a CEL. Even with both new coil packs, that's still unusual on a long run.

I did similar things to the ABC pipes, and I've got lots of pictures of all these things...

Nick

Welwynnick

I removed all the ABC pipes around the engine, and replaced them with new pipes with compression connections:



Taking a closer look at the pipes that were already protected by reflective insulating sleeves. I cleaned the sleeves, but the pipes are as they came off the car. They're in very good condition:



However, the feed pipe from the pump to the regulator wasn't protected, and looks horrible. Draw your own conclusions.



Therefore I protected all the new ones with firesleeve. This is 30mm ID, which is too large. 25mm is ideal.

1c35bbd5-fa8a-4d94-b7b1-ddef5d84a7cf_zpsfd082764.jpg?t=1416907582

If I was ever mad enough to buy another car with ABC, I would do all that straight away as a matter course, regardless of the condition of the pipes.

Fitting those pipes can be difficult. What I did was support the engine, undo the engine mounts and drop the front of the subframe.

In this picture you can see how easy it is to access the pipes, the PAS output connection, the diverter valves, and even the ABC output banjo - that's SO difficult otherwise.



Nick

Welwynnick

Getting back to the IC system, here's what I did to the coolant pipes:





And here are the coil pack shields:





Nick

F1BHP

Very nice Nick. You have put a lot of time into preventative maintenance and I hope it pays off for you. You say you have misfire problems are you thinking this is a coil problem or something else?

Flight Test

Thanks for the pictures! What kind of insulation did you use on the water tubes? It almost looks like you sewed the seam together over all the mounting standoffs. Impressive.

Did you notice any difference in water temps?

I figure a lot of heat goes into those water lines under the coil packs. I have started my car when it was dead cold and in just a couple minutes you can feel the warmed water going through the intercoolers. It should definitely not heat up that fast.

I Plan on using some of the advanced aerogel insulation to wrap those lines and also insulate the intercoolers themselves. You can get amazing insulation properties from a very thin amount of insulation. It is expensive but nothing else can touch its insulative properties.

Thank you so much for sharing your efforts.

Welwynnick

I couldn't find the actual products, but these are the sorts of materials that I used. They're relatively cheap, simple, readily available solutions, which is what I tend to go after.

http://www.ebay.co.uk/itm/Heat-Refle...item1e943408a0
http://www.ebay.co.uk/itm/010419-DEI...item2ed595c062
http://www.ebay.co.uk/itm/REFLECTIVE...item4622824d7f
http://www.ebay.co.uk/itm/Engine-Bay...item20f057f0a2
http://www.ebay.co.uk/itm/HONDA-NISS...item51b3aec545
http://www.ebay.co.uk/itm/HEAT-REFLE...item3a74a34dbe
http://www.ebay.co.uk/itm/2x-Heat-Sh...item4183613853
http://www.ebay.co.uk/itm/Heat-Shiel...-/351212056919?

Insulating the coolant pipes was tricky due to the brackets. I cut it all out of sheet, and stapled it all together. In hindsight, winding a tape would have been easier, but then it might have been difficult to fit the coil pack heat shields. There's not much room.

The other solution might be to make the coil shields larger and deeper. They could extend down further and cover the cooling pipes as well, but stop short of the turbo oil, coolant and wastegate pipes (which are the reason for the gap in the stock heat shields, and a contributor to the coil pack problems).

If I were to do it again, thats what I would do. Getting the pipes back on was quite a pain. I already had them off to get at the turbos, but I'm not sure I'd ever be motivated to remove them ever again.

My temps do run low, but them I've got a huge HE, Pierburg pump and programmable pump controller. Can't say what the contribution of the insulation is.

The thing that does stand out is how warm the IC coolant gets when the car has been standing for a while after a run.

Nick

shardul

iTrader: (1)

has one tired a colder tstat? i have one laying around

Flight Test

Thanks, do you think there is enough room to slide insulation around the coolant pipes if they remain installed in the car? I assume you can get at them once the coil packs are removed.

Shardul, my engine temps stay pretty reasonable at around 190ish, but a lower thermostat may help. I do like making sure the engine stays warm enough to get the oil temp over 212F to get all the condensation evaporated out of the oil.

Lots of good ideas here....

Welwynnick

In hindsight, I think that would be the way to do it. It would be pretty impossible without removing the coil packs. There's not much room, so you'd have to keep the insulation thin - no doubling up, otherwise the coil packs won't go back in properly.

Nick

F1BHP

Have you guys had any experience with ceramic coating?

I am thinking about doing the ceramic coating on the turbo/manifold housing, I am pulling it out anyway to do a billet wheel upgrade.