Heat wrapping

[Bolt Speedman]

So I recent read the article about exhaust heat wrapping to help keep the engine bay cooler, so I started to wonder if this could be applied to the the air intake to help keep heat out? Anybody have any thoughts?

 

[old-git]

Yes. Works both ways. Probably better, however, to use a reflective wrap as this will be move effective at the relatively low temperatures you are dealing with.

 

[Turboshaft]

some of my buddies use some sort of firewall to separate the intake from the rest of the engine bay... don't know how effective that is though.

 

[old-git]

Ideally, IMO, the intake should be separated from the engine bay heat. The intake pipe has to pass into the bay and this should be protected from unwanted heat.

 

[obi_waynne]

Many manufacturers are taking the air inlet from the front wing now (VAG group particularly).

 

[old-git]

Many manufacturers are taking the air inlet from the front wing now (VAG group particularly).

And about bloody time

 

[Country Bumpkin]

Wrapping exhaust manifolds is about keeping the heat in more than stopping it from getting out if you can understand that. Keeping spent exhaust gases hot, aids quicker exit, on turbocharged cars you want to keep those gases to propel the turbo. Yes it can assist engine bay temps slightly but it's true purpose is as above.

 

[old-git]

Wrapping exhaust manifolds is about keeping the heat in more than stopping it from getting out if you can understand that. Keeping spent exhaust gases hot, aids quicker exit, on turbocharged cars you want to keep those gases to propel the turbo. Yes it can assist engine bay temps slightly but it's true purpose is as above.

Hi CB. I think that, although what you say is true, you are missing the point, slightly, of Bolt's orignal question. He want's to know, I thnk, if heat wrap used for keeping heat in exhaust sytems can be used to keep engine heat from reaching the intake air.

 

[Country Bumpkin]

I understand that old chap , I just wanted to add the real side of the issue so that the younger fraternity don't think that that's all the stuff is for.
Hell, most of the youth think a NISMO sunscreen will add b.h.p. whereas we know it only works if you have H.K.S. badges on the wings too.

 

[old-git]

I understand that old chap , I just wanted to add the real side of the issue so that the younger fraternity don't think that that's all the stuff is for.
Hell, most of the youth think a NISMO sunscreen will add b.h.p. whereas we know it only works if you have H.K.S. badges on the wings too.

I guessed as much

Yes, I must remember to put the shopping list on the side when the Elan is finished If I was being sponsored then, yes, acceptable, but why give them free publicity? Can't quite grab the logic, unless it is a bragging/show off/look what I have spent type of thing.

Although a 'soon to be retired' wrinkly, I appreciate that I thought I knew it all when I first started playing with cars. Mind you, it was far less complicated back in the dark ages, no problems with ECUs, turbos (for most of us) or EFI.

All you could do was head work, cams, exhaust, and carb mods/replacement. If you were really serious you upgraded to forged pistons, steel crank, etc.

These days it is far more complicated. When I came back to the fold after being out of it between 1985 and 2003 I was shocked by the advances that had been made! I am still trying to catch up. My son, who knows very little about the basic principals of tuning or how an engine actually works (although he is learing fast), is happy to take one apart and upgrade to different ECUs, turbos, etc.

As for ICE, I haven't a clue but my son knows more about it than I ever will (or want to for that matter).

We tend to forget that we also once knew it all. It's only when you get older you realise that the more you learn the less you actually know and it gets harder to learn new tricks.

Just had a thought, how many of you that are under 30 read tuning books? 'How to make your car handle', 'Engine Management Techniques', 'Turbocharging Performance handbook', etc.

 

[dpsubaru]

Wrapping exhaust manifolds is about keeping the heat in more than stopping it from getting out if you can understand that. Keeping spent exhaust gases hot, aids quicker exit, on turbocharged cars you want to keep those gases to propel the turbo. Yes it can assist engine bay temps slightly but it's true purpose is as above.

may look like a fool here but, are you saying that for turbo charged cars better not to seppd up the exit of exhaust gases so they are retained for the turbo therefore it is detrimental if you have a turbo to wrap the exhaust?

 

[MasterAuron]

Just had a thought, how many of you that are under 30 read tuning books? 'How to make your car handle', 'Engine Management Techniques', 'Turbocharging Performance handbook', etc.

I do. I have a number of books but most of the information I need is avaliable on the internet to be honest. The most useful books to me at the moment are my engine building ones; Engine Builders handbook by Tom Monroe and another I forget the name of lol. I'd also recommend A. Graham Bells book on performance tuning as a good all-round book.

In my experience handling, electronics and mapping information is all readily avaliable on the internet, good engine building and tuning techniques are not, however. Cylinder heads are somewhat of a dark art I'd rather leave to the professionals though lol.

 

[MasterAuron]

may look like a fool here but, are you saying that for turbo charged cars better not to seppd up the exit of exhaust gases so they are retained for the turbo therefore it is detrimental if you have a turbo to wrap the exhaust?

I don't think that's what Country Bumpkin is saying. You can't "retain" gases for the turbo, you want them to pass in and out as quickly as possible. What you want to retain in the manifold and exhaust is the HEAT, as hot exhaust gases have more kinetic energy and higher pressure. This aids spinning the turbo.

Wrapping the exhaust is in theory also beneficial as the hotter gases can escape much more quickly, creating an area of lower pressure post turbo. It is the pressure differential between the exhaust gases pre and post turbo that determines the amount of work the turbo can do. You want the pressure to be as high as possible pre turbo (this is where retaining heat and manifold design comes into play) and pressure to be as low as possible post turbo (retaining heat, exhaust design) as this creates the largest pressure differential possible.

Comprende?

 

[Turboshaft]

I've got A Graham Bell's four stroke performance tuning as well , good book , still hunting for more on ebay and amazon as they are quite pricey to buy new.

 

[HDi fun]

I don't think that's what Country Bumpkin is saying. You can't "retain" gases for the turbo, you want them to pass in and out as quickly as possible. What you want to retain in the manifold and exhaust is the HEAT, as hot exhaust gases have more kinetic energy and higher pressure. This aids spinning the turbo.

Wrapping the exhaust is in theory also beneficial as the hotter gases can escape much more quickly, creating an area of lower pressure post turbo. It is the pressure differential between the exhaust gases pre and post turbo that determines the amount of work the turbo can do. You want the pressure to be as high as possible pre turbo (this is where retaining heat and manifold design comes into play) and pressure to be as low as possible post turbo (retaining heat, exhaust design) as this creates the largest pressure differential possible.

Comprende?

Hot gases do have higher kinetic energy than colder ones but colder gases are denser so would it make all that much difference? Or is it the overall loss of energy from the system which weakens performance?

I can see the sense in keep the intake well away from heat sources so wrapping the exhaust is going to be beneficial. It will also aid cat warmup thus reducing CO emissions etc.

 

[dpsubaru]

Thanks MA, all clear,

 

[Country Bumpkin]

Yes, well explained MA, better than my quick reply which was probably vague to understand. I'm more used to explaining things like this to apprentices who are stood in front of me and with the ability to show/explain physically how/why things happen.

 

[Tiburonmad]

HI this heat rapping and heat shielding talk got me thinking about the air the turbo draws in from the engine bay threw the filter would it matter if the air was colder from an outside source or does is get so hot in the compressor that it does not matter?

 

[pgarner]

imo it makes little difference. cooling after the turbo would be more important

 

[old-git]

imo it makes little difference. cooling after the turbo would be more important

Have to disagree with you on this one, PG. The intercooler will reduce intake temperature by a set amount, regardless of original temparature. If the air entering the turbo is 20 degrees hotter than ambient, then the temp of the air exiting the intercooler wil be correspondingly hotter, albeit maybe not the full 20 degrees. The colder the air entering the engine the more power can be produced so it needs to be as cold as possible.

So, my intake is separated from engine bay and takes air from outside the car. The duct from filter to turbo will be insulated.