Lagging turbo pipes, exhaust manifold, turbos, down pipes.

[Davezj]

I know it has been talked about before, and some of you have done it.

Which of the following would you do.

1. lag the inlet side of intercooler to turbos (keep heat out).

2. lag output side of intercooler to throttle body (keep heat out).

3. lag plenum chamber (keep heat out).

4. lag exhaust manifolds (keep heat in).

5. lag turbo exhaust side blanket type (keep heat in).

6. lag down pipes (keep heat in).

Reason i am asking is i have just driven to work with a temp sensor just below the front strut bace. temp got to 70degC ish. that is a 6 mile trip in 30mph road limits. oil hasn't even got to temp by this point.

after some thoughts and comments.

this seems to be a cheap and possible good thing to to do.
I have been looking at various lagging materials and types (tubes, sheet, wraps,etc,etc). most ceramic fibre types.

What do you guys think?

[VR4 MAD]

This is something I too have been thinking about doing...........:thinking:

My thinking is to start with the exhaust wrapping first. This has two advantages.

One, keeping the heat in the exhaust helps keep the exhaust gas temperatures up which causes the gases to flow faster and does have some performance advantages, though they maybe only small.

Two, keeping the heat in the exhaust will help to keep the under-bonnet temperatures down which has a beneficial effect on inlet temperatures. If the insulation is done well enough, may negate the need to insulate the inlet pipework. /rally

There is a down side to this though I'm told. The wraps can hold moisture which can lead to accelerated corrosion problems to the exhaust pipework that is wrapped. Not sure how bad this would be and whether this applies to stainless steel pipework too or not. /pan

Hope that may help a bit.

/toycar

[Paul C]

I thought if you lagged the downpipes/manifold that there is a greater chance of internal wear and the potential to crack them. The heat maintained in the exhaust helps to remove gases quicker but it has negative effects in the long term.For an every day driver car is it not better to leave the pipes unlagged for relibility.

[bradc]

I think that lagging the exhaust is the big one, the air spends such a short amount of time in the intake pipework and so little of it it close to the sides of the pipe that it wouldn't really matter.

Try the exhaust first and see what happens

[Throbbe]

Corrosion issue has already been highlighted.

The other one is to make sure you don't have variations in lagging thickness (or even bare patches) to avoid problems with localised hot/cold spots.

It will help performance, but I've always seen it as one of those mods that you leave to last, or at least do while you've got the manifold off to match the ports or put a different one on there.

[Davezj]

my inital thought was to bring the under bonnet temp down. and i found out my temp sensor max is 70degC anything above that and it just displays HHH (Hot Hot Hot).

when working on the car after a run out, the stut brace and turbo Y pipe are usually too hot to hold.
i know a hot strut bace is not a performance stopper but if that is so hot, then every other bit of metal under the bonnet is going to be very hot.

If what i have read from other threads is true then the fact that the inlet side of the intercooler is hot/warm aslo, then it must be the air entering it that makes it hot.
how hot is the compressed air coming out of a turbo anyway. if it is hotter than the normal engine bay temp then lagging the turbo pipes will only make this temp worse.
i feel a temp sensor move coming on. i will dangle it in the pipe after the Y pipe and see what happens. if it is colder than 70degC then it would be worth trying. then repeat after lagging and see if it make any difference.

suppose i will have to do this before and after measurement after every change in lagging.

unfortunately i don't know when i will get round to doing this.

does anyone have materials in mind for the different lagging areas?

[phosty]

my inital thought was to bring the under bonnet temp down.

Or try a vented bonnet? It shouldn't reduce the performance from where you are now and may even help the intercooler do it's job. Might need to look at undertrays though...

[Davezj]

yes that would probably be good idea but i don't really like the look.

i don't know what it is about bonnet vents they just look like your trying too hard with the bling side of thing. it is just a personal thing. i know they work and they are a good idea. there are just too many cars knocking about with crappy vents that s;poil it the rest of the cars that really need them.

so i won't be going down that route.

[Davezj]

Just done a run out and i found the air temp inside the turbo pipe just after the Y pipe metal section has been up to 60degC and the motorway and round town when you are only on part throttle. but when WOT the temp falls to about 50degC.
on WOT there will be a lot of wind chill factor going on with all that air rushing past the sensor, so that could explain some of it.

i have ordered some tape 3mm think which i will try to put on the metal Y pipe to see if it makes a difference.
i will up date later.

[bradc]

remember that when turbos compress air they heat it up. I doubt there will be much of a gain in wrapping the pre intercooler pipes. I would be more concerned in measuring the temp at the intercooler, and then at the throttle body, then perhaps wrapping that pipe to insulate the cool air from the engine bay temp

[Davezj]

that is a good point, but i thought i would start with the easiest first. just to see if made a difference. If it doesn't then i will try the output piping.

There will be no gain in performance for my car as it is standard build. or if there is it will not really be noticable. i just thought it would be a interesting thing to try. It's the engineer in me.
That also why my spelling is rubbish it's goes with being an engineer.

i will let you all what happens.

[bradc]

it will still help though, lower engine bay temps are always a good thing

[Paul C]

Just done a run out and i found the air temp inside the turbo pipe just after the Y pipe metal section has been up to 60degC and the motorway and round town when you are only on part throttle. but when WOT the temp falls to about 50degC.
on WOT there will be a lot of wind chill factor going on with all that air rushing past the sensor, so that could explain some of it.

i have ordered some tape 3mm think which i will try to put on the metal Y pipe to see if it makes a difference.
i will up date later.

is that to keep the heat out i guess? It could have a negative effect on what your trying to achieve.Either way let us know your results.

I havea temp sensor fo t map ecu 2 mounted in the outlet of the intercooler, if i remember right it measured 1 degree lower than ambient. This isn't a factual every day occurance its just one of the ocassions that i can remember.

[Davezj]

is that to keep the heat out i guess? It could have a negative effect on what your trying to achieve.Either way let us know your results.

I havea temp sensor fo t map ecu 2 mounted in the outlet of the intercooler, if i remember right it measured 1 degree lower than ambient. This isn't a factual every day occurance its just one of the ocassions that i can remember.

yes your are right, if the internal temp of the turbo pipe is less than the engine bay ambient lagging this pipe will actually raise the engine bay temp. asit is not being sinked away by this pipe.

i will reposition the sensor in the flex pipe before the throttle body to see what happens.

i pulled the output intercooler pipe off the bottom of the hard pipe near the reicrc valve yesterday, and then wished i hadn't as it took 20mins to put it back on, what a tight bend in the pipe. i think i have the method of getting it back on more easily now.
i pulled it off to see if there was anything in the bottom of the intercooler, oil ect. there was a little bit of oil residue in the bottom of the pipe, but i don't think that is anything to worry about as the entire turbo pipe inlet system has a oil vapour residue all over te inside of it not much just a light coating.

[Davezj]

well i didn't realise the intercooler made so much of a difference.

crusing on the motorway 30-35 degC.
round town only 30 or less degC.

That is a good change.

30-35degC air temp going into the engine doesn't sound too bad.

I haven't been out to give it a boot yet and get the engine Temps really hot, i supose that is the nest thing i will have to do and monitor the response.

[bradc]

what about in the intake manifold? I bet those temps are hotter than 30C

[Davezj]

yeh i think the air will get be hotter as it goes through plenum and inlet manifold, but there is not a lot you can do about that.

apart from putting a insulative jacket over the entire plenum then use a insulative gasket between the inlet manifold and the engine or plenum to manifold gasket as the manifold is so small.
Which would be quite complex but doable and the material to insulate them would have to be a better heat rating as they are connected directly to the engine. But that is pie in the sky for what i was planning.

[Davezj]

how hot do turbo's get has anyone seen them glow.

if so that will be be very hot!

I think it is in the 600-1000 degC range.

so i think turbo jacket's will be expensive.

[Kenneth]

how hot do turbo's get has anyone seen them glow.

if so that will be be very hot!

I think it is in the 600-1000 degC range.

so i think turbo jacket's will be expensive.

have had mine just about see-through :P

A mate and I went for a drive, jumped out at the end of it to check how hot the turbos were and as soon as we opened the bonnet (it was night time) the engine bay was lit up.

[Davezj]

are they standard TD03 or bigger.

[Davezj]

well i have got my magic paste.

Time for some experiments.

Thought i would coat a bit of thick metal pipe in the stuff the put the other end in a burner to see what heat transfer i get. this may take some time.