farmerbrown
yes an air pump is an engine ..same way how an engine brake works but in reverse
yes the turbo will spin blowing cold air ..but does it have enough energy to make boost ?

just like most petrol engines the turbo can be spinning but you will be in a vacuum at idle
a bit like the Td5 when it goes into limp mode ..the turbo is still spinning but no power

did I mention the word energy

if we had equal weight on a set counter scales ..we would be back at zero

Gottschalk said:

Yes it may be important, but its not the MAIN source of energy

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nobody said it's the MAIN source though

Farmer Brown said:

....I did do chemistry at university so I do know a bit about gases and how temperature affects them.

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i really respect that but IMO it might not be the best approach for the Td5 engine management though... is the following report clear enough for you? (the fact that it's not made under the hood is irrelevant for the engine management cos the reading of the MAP/IAT is not involved in the experiment https://docs.google.com/file/d/0B1DKgBxqE0JEME5wQ1pIc1N5dU0/edit?pli=1

chemistry at university so I do know a bit about gases and how temperature affects them.[/QUOTE]

so this means you can explain how exhaust gas temps work with turbos right

as for the main source

if there is no heat there is no boost mate
the td5 can still run in limp mode but the fuelling is limited no fuel no heat
means no power

[/QUOTE]

ozzyboydeano said:

chemistry at university so I do know a bit about gases and how temperature affects them.

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so this means you can explain how exhaust gas temps work with turbos right[/QUOTE]
It means I understand that when the fuel and air combusts it explodes and the resultant increase in gas and pressure pushes the piston down and then what's left of the gas and pressure created by the explosion goes out through the exhaust manifold with the gas to spin the turbo. Now when the exhaust gases go through the turbo they will cool as the turbo extracts some of the energy out of the exhaust gases but I still don't think that wrapping insulation round a turbo is going to give you any more boost. Any time anyone else I've come across has talked about insulating exhaust manifolds, turbos and exhaust It was not because they thought it would increase the boost pressure but because they wanted to keep the engine bay cooler and keep intake temperatures down as a cooler engine breathing colder air makes more power.

Farmer Brown said:

..... 1. insulating exhaust manifolds, turbos and exhaust It was not because they thought it would increase the boost pressure but because they wanted to keep the engine bay cooler and keep intake temperatures down as a 2. cooler engine breathing colder air makes more power.

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1. insulating the manifold and exhaust is for thermal protection yes but for the turbo it has that demonstrated boost gain too...which as said is not extreme but noticeable
2. lower IAT(inlet air temp) means better combustion that's why it's more power not because the EGT is lower, the gain in turbo speed/power due to greater EGT has less effect on overall engine power than a good combustion that's a fact that's why a turbo blanket is good cos it keeps higher EGT within the turbo making it spin faster while the engine runs better due to colder intake

Problem is everyone is mixing high performance time attack cars with fooking land rovers!

Half the **** will make a difference to a TT car but will do near enough **** all to an old TD5.

I cant see that wrapping a TD5 manifold would do anything but exacerbate potential warping issues.

Either way even a very highly tuned TD5 is not going to give off enough heat from anywhere to affect inlet temps or under bonnet temps, to any noticable or worth while degree.

@ozzy i cant really rev to 2k as ive no rev counter so it would just be a total guess at best.

at the end of it turning the boost up 4psi is not going to make an enourmous difference to fuel consumption but it will improve driveability. That was the original arguement.

ozzyboydeano said:

farmerbrown
yes an air pump is an engine ..same way how an engine brake works but in reverse
yes the turbo will spin blowing cold air ..but does it have enough energy to make boost ?

just like most petrol engines the turbo can be spinning but you will be in a vacuum at idle
a bit like the Td5 when it goes into limp mode ..the turbo is still spinning but no power

did I mention the word energy

if we had equal weight on a set counter scales ..we would be back at zero

Click to expand...

the only energy the turbo uses is kinetic, heat causes the gasses to expand ie more pressure the greater the heat,its the pressure not the heat per se thats important, as with any engine part subject to heat it the metal will have an optimum temp and wont like quick cooling or heating, id still think on an average car or landy you wouldnt notice any extra gain

Where do you guys get the turbo blanket?

I have no heat shield under the bonnet but I do have a wrapped down pipe, a turbo blanket would be a good heat shield I think?

That's the item i ordered http://www.ebay.com/itm/HIGH-PERFOR...567560?hash=item2370c13cc8:g:5OkAAOSwZVlXu-Oc it came quite fast from China , if you get one you'll have to remove the rod from the turbo and make a hole through the blanket to give access to the rod to actuate the wastegate or cut the blanket abeam the rod as to be abe to fit it(that's what i did then fixed it with paper clipper cos i was lazy but i regret i didnt do it better)

if you fit one come back and tell us if you feel a slight improvement in the throttle response or not cos some guys here are thinking that i'm lying

As long as you're happy

sierrafery
the reason you are experiencing the better throttle response is because your containing the heat this heat is kinetic energy

heat expands this pushes on the turbine wheel bit similar to what a combustion stroke does it pushes down

sitting traffic lights for a few minutes this brings back the turbo down to idle temps
also other driving conditions slow moving or negotiation heavy traffic (low boost situations ).the turbo is cooling down .... turbo blanket contains the heat so when the driver accelerates heavily the turbo hot side is already up or near operating temps

the flip side means longer idle down time or install a turbo timer some turbo timers can self adjust depending on driving conditions



banks5152
any turbo engine works the same way regardless of high HP time cars
since being a diesel mechanic I treat all diesel engines as high performance engine regardless of its age or HP out put ...., diesel engine needs high compression to work correctly

warping the exhaust and turbo see all different temp range ...for example a 10 minute drive around the city the turbo has changed temps hundreds of times (wider temp scale)
adding in a blanket contains the heat now the turbo wont need to cool off heat up cool off heat up means less prone to warping

under bonnet temps the engine block should stay the same due to the cooling system coolant runs around the block ...my self has removed bonnet seals to try and allow some under bonnet temps escape .... after a drive if I can my hand on the bonnet where the seals would of been I feel hot air escaping (every small thing helps )
eventually other component's suffer from heat soak

fuel consumption all comes from the driver ..I nurse my td5 travelling to and from work there will only be a few occasions where I use full boost
there has been times where I have booted the hell out the engine to and from work
now that this driving style changed instead of boost pressure average is about 8 to 12 psi I now drive at 16 to 17 psi i then use more fuel

the ECU is doing realtime calculations more engine load = more fuel ,,,,,more fuel more heat generated
for example my old Nissan with a d21 engine i had the waste gate blocked off max boost pressure was 10 psi (regardless of the waste gate being disabled ) even at redline still had my 10 psi

i then turn the fuel pump screw in this gave the engine more fuel ..boost pressure rised to the point enough is enough
fuel consumption killed me to a point i changed my driving style

no worrys that you don't have a rev counter ..i never look at mine i always look at my boost gauge its a much better indication how much load the engine is @

flat said:

Where do you guys get the turbo blanket?

I have no heat shield under the bonnet but I do have a wrapped down pipe, a turbo blanket would be a good heat shield I think?

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you can use the same wrap that you used on the down pipe
just means you have to physically wrap the turbo HOT SIDE ONLY instead of sliding over a sock wrapping your own turbo... sky is the limit on thickness

little tip soaking the wrap in water first means when it dries out with heat it shrinks and pulls tight resulting a nice snug tight fit

ozzyboydeano said:

you can use the same wrap that you used on the down pipe
just means you have to physically wrap the turbo HOT SIDE ONLY instead of sliding over a sock wrapping your own turbo... sky is the limit on thickness

little tip soaking the wrap in water first means when it dries out with heat it shrinks and pulls tight resulting a nice snug tight fit

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Yeah I did that when I wrapped the downpipe. If I wrap the turbo what about future maintenance? Won't the wrap make it a ball ache?

flat said:

Yeah I did that when I wrapped the downpipe. If I wrap the turbo what about future maintenance? Won't the wrap make it a ball ache?

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there is no maintenance you would only be wrapping the exhaust snail of the turbo

unless your planning on changing the turbo every couple of months yes then it will be a ball ache
but wrapping and un wrapping isn't really a hard job

the ball ache is if you do wrap the manifold or turbo just allow some extra idle time prior to shut down
I work shift work so I don't like my engine idling for 1 or 3 minutes specially during the night when I get home

turbo savours work great i have installed something similar (accumulator tank) i stole the idea from a dump truck that i was working on

ozzyboydeano said:

there is no maintenance you would only be wrapping the exhaust snail of the turbo

unless your planning on changing the turbo every couple of months yes then it will be a ball ache
but wrapping and un wrapping isn't really a hard job

the ball ache is if you do wrap the manifold or turbo just allow some extra idle time prior to shut down
I work shift work so I don't like my engine idling for 1 or 3 minutes specially during the night when I get home

turbo savours work great i have installed something similar (accumulator tank) i stole the idea from a dump truck that i was working on

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I always let me engine sit at tick over for a minute or so. Will look into wraps etc.

flat said:

I always let me engine sit at tick over for a minute or so. Will look into wraps etc.

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I installed something similar on a normal drive low boost situation I don't need to worry about idle time
http://turbosaviour.businesscatalyst.com/about-the-turbo-saviour

sierrafery said:

nobody said it's the MAIN source though


i really respect that but IMO it might not be the best approach for the Td5 engine management though... is the following report clear enough for you? (the fact that it's not made under the hood is irrelevant for the engine management cos the reading of the MAP/IAT is not involved in the experiment https://docs.google.com/file/d/0B1DKgBxqE0JEME5wQ1pIc1N5dU0/edit?pli=1

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I asked you to provide a link to an experiment done on a test bed and you did that. I see what they say but I am still struggling with this one. I own two of the exact same Cummins engines they use (in tractors) both of which are putting out over 900nm at full torque and given that changing gear and not wanting boost to drop off or requiring boost from a standing start isn't an issue (as the tractors have power shift and they tend to do constant pulling when working) I wouldn't see the point in fitting one. I could just get a remap and add miles more power rather than going to bother of insulating the turbos for something that I doubt would make much difference and may cause additional issues.

As bankz said above we are after all dealing with old landrovers here and to be honest I don't see what difference it would really make to one of them. These things take that long to change gear that you are going to struggle to maintain boost between gear changes no matter what you do and in anycase if your driving your landy you need your power when towing and you come to a hill or when you are off-roading steep stuff so in most cases all you want is the engine to do hold on, you are not bothered about turbos spooling up quicker when you change gear. I don't know about you but I'm not into flying away from the lights in my Landrover, mainly because I've seen glaciers accelerate faster than it. If there are benefits from reducing engine bay temps through insulating the turbo/manifold/exhaust and therefore intake temps it is not as if there is loads of engine insulation that keeps the heat in the engine bay, my Landrover spends most of its time howking through fields with water and mud splashing all over the engine. Normally the heater has just about warmed up by the time I arrive where I was heading.

As I said before I know of people insulating turbos, manifolds, exhausts before on highly tuned RS's, skylines, scooby's and evo's producing big HP in order to keep engine bay temps down and help intake temps but these are completely different kinds of things to an old landy doing 180hp (with major tuning) and only revving to a few thousand revs, most of us have way less power than that and no intention of pushing things that far. Also as bankz said, if there is a risk in warping the manifold then I certainly wouldn't do it as it is not worth the risk. Also having to wait longer in order to let the heat out to help prevent turbo bearing damage is also a pain. I tend to cruise at the end of journeys and will let the engine sit at idle for a bit but I can't be arsed waiting a few minutes. You may find that you get a similar result to what to what you say you are getting from giving your exhaust manifold a good port and polish to maximise gas flow through it, but then again it is an old landy.

I stand by what I said earlier, it is not heat that drives a turbo but the kinetic energy released by the explosion of the fuel air mix in the cylinder. When something explodes the potential energy it contains (in our case in the diesel) is transformed into kinetic energy and some heat energy. The kinetic energy drives the particles involved in the explosion out from the centre and in our case the expansion and movement of particles (gas molecules) resulting in an increase in pressure push the piston (and spin the turbo when the exhaust valve opens, there is some pumping force as well by the piston being pushed up) and the heat energy created radiates out from the explosion heating the surroundings. The kinetic energy conserves the potential energy of the diesel and the heating of the surroundings is a non-conservative process. When the expanding gas flows through the turbo the turbo extracts work from the gas and this results in the temperature of the gas dropping. Now it may be according to the experiment you linked to that if you reduce the heat wastage you retain more kinetic energy in the explosion to spin the turbo faster but you have to remember that it is the kinetic energy doing that and not the the heat. Heat does not drive a turbo, kinetic energy does, they are two completely different things.

I say again, nobody said that heat is driving the turbo, at least not me, read again what i said, that's what i said when i butted in:

sierrafery said:

....heat in the turbine side of the turbocharger is not neglectable at all even on small turbos(provided it's gained in normal operating conditions not by overfuelling).....

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after there were few replies posted by Johnlad, bankz and Gottschalk that heat has nothing to do with the turbine e.g.:

Gottschalk said:

Basically johnlad and bankz are totally correct. The turbo spins up from the flow of exhaust gases passing through it. The fact that this is hot air is nothing to do with anything turbo wise, exhaust gases are always hot!

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and i wanted to sustain ozzyboydeano who has tried to explain that it does and the experiments are showing clearely that.... so that was the subject nobody sustained that the turbine is not driven by exhaust gas flow just that heat can't be neglected in this ecuation and as long as nobody proves that i'm lying i reiterate that it's noticeable on the Td5 too(on mine it is) so IMO no need to argue untill somebody who sustains the contrary just for the sake of argument doesnt do an individual objectiv test on his own vehicle

MERRY CHRISTMAS TO ALL !