Cool under the bonnet

[lee celtic]

Hi All

Just a general question .

I am thinking of bandaging my exhaust to reduce the temp under the bonnet and that made me think about wraping the intercooler hoses and air box with insulation to stop them picking up radiant heat .

Does anyone know how much affect this would have on a 200tdi and is it worth the hassle and cost .

cheers Lee...

[Drift]

One of my intercooler pipes is steel  :?

[lee celtic]

And :?:  :?

[Drift]

And :?:  :?

Dunno realy  :?  :lol:  just thought I would mention it as an option  

[lee celtic]

Part of my hoses are metal as well but this still soaks up heat from under the bonnet ie. the cool air leaving the intercooler is re heated because the hoses or steel pipes are hot thus loosing density .

What I want to know basically is the power to pound ratio  

and is it worth doing :D

[Drift]

As a thought could it be beneficial to wrap the pipes in metal heat reflective foil ?

I half half heartedly tried this on my modifide air intake, but didnt do a great job as you may see in the pic, it all fell off  :oops:

[winchman]

This may have some effect on performance as there will be an optimum exhaust temp, but you need some one better than me to advise you.
I have seen it on race cars though.

[waveydavey]

I would be stunned if it made an appreciable difference.
Once at speed (any speed) the airflow will bring the exhaust heat down under the car; the cooled air after the intercooler is at the top and quite honestly the air flow through the manifold is high enough that even if the metal is hot it would hardly make a difference. That is why you need a cooling matrix for the intercooler.

Try sticking a thermometer under the bonnet and have a look at the temperature as soon as you stop.

[carbore]

Having spent a lot of time playing whit track/race cars and talking to my mates who do the same.....

My Elise has lagged exhaust manifold.
This is due to the fact that there is little air movement in the Engine bay (Mid Engine/Undertray) and the exhaust manifold is very close to alternator, petrol tank and other such things.  Therefore removing the radiant heat that goes out is desirable.

I Use "socks" that are a loose fit over the manifold.
http://www.demon-tweeks.co.uk/products/ProductDetail.asp?cls=MSPORT&pcode=NIM11246

No cheap but my Elise is a bit of a monster!

I did consider using exhaust wrap, however my friends who tried it say that it is prone to cracking exhausts due to expansion.  It ok on a straight section, but if there are any welds an joins then its a bit iffy.


Re inlet hoses.
I use silicone reflective hose for the air to filter hose. Again expensive but it reduces inlet temps resonably well by all accounts.
http://www.demon-tweeks.co.uk/products/ProductDetail.asp?cls=MSPORT&pcode=SFSSFD31-1

I have also put heat reflective tape all over the filter housing and manifold.  This also reduces temp especially when sitting around. This was £5 for a reel of ebay! and I tested it with a IR thermometer by the fire and it works well!
http://cgi.ebay.co.uk/Thermo-Shield-Heat-Wrap-Self-Adhesive-Tape-1-5-x-15_W0QQitemZ130176606001QQihZ003QQcategoryZ38786QQssPageNameZWDVWQQrdZ1QQcmdZViewItem


People spend A LOT of money on this for racing cars as it does make a difference, however its really the icing on the cake, its not difficult so its tempting to do for a weekend job, but things like bigger intercoolers make performers jumps not little steps that heat management does.

The one thing im not sure about is what happens to this stuff when it gets wet! if its not done by other 4x4 competition vehicles then there  is a good reason and is suspect that its to do with water/mud ??

[bilge rat]

that takes me bavk used to work on lotus , doing upgrades to track spec 190 upgrades and the like . miss it , infact my little girl i named elise !. any way back to the disco ,i put a bit of heatproof material between the manifolds,  did rap some round the top intercooler hose as a trial but to be honest didnt notice a great deal of difference. as for exhaust not so much heat but reduce back pressure slightly i would say would be more worth while, replace the centre box with a straight through . think paddoks do them . or even remove the tail pipe although this does not do much anyway. have you tweeked the pump, you can boost the turbo pressure on the 200 slightly. freeflow filter , plenty to go at. alan......

[carbore]

I like the look of the JE engineering ECU upgrades, I think my TD4 Freelander will get one once its out of warranty.

[lee celtic]

Yes I have tweeked the pump (Thanks Orange landy) and I have a K&N

What I'm thinking of is when off road and not moving fast the engine bay gets hot and having popped the bonnet while off road to check stuff like you do the top hose and steel air box have been hot to touch .

My first thought was a ali plate fitted between the engine and the air box like a heat shield then to use polystyrine veneer wrapped around the cylinder of the air box then covered with aluminised tape ,then heat proof exhaust rope around all the bends and ribbon around the straight bits again covered with ali tape . I have two 5" motorcycle cooling fans to fit to the intercooler to increase low speed air flow and as soon as the exhaust starts to blow the middle box is history :D

I did see kenlow have made fans that blow down through the bonnet to cool things down but the thought of blowing a bow wave straight down onto the engine makes me think No.

[Range Rover Blues]

Well I noticed that the bottom pipe on the 300TDi RRC is insulated from new, don't now whether it's a noise or heat issue though.

It can't hurt to insulate them, but the exhaust wrap is a good idea, it keeps the speed of the exhaust gas higher so should release a little more power.

[carbore]

Id be careful about using polystyrine could melt/catch fire.
  The thermal tape I linked form ebay is great. I stuck some one a bit of card and tested it with an IR thermometer both on and off the tape when I held the card up to the fire. Made a huge difference.  Slapped it all over the filter cone on the Elise.

[kourgath]

I have used the same 'sock' stuff that carbore linked to from Demon Tweeks.

Reduced underbonnet temp noticably.  Previously used the wrap stuff, sock way easier to fit, just not as neat.  The 4.6 generates so much heat when do stag do's off-road that I had to add more fans and cut holes in the bonnet to let the hot air out.  Pootling along a 5mph doesn't create an underbody air current :-)

[L90OOK]

Surely improving air flow through the engine bay would be a better use of time & money? ...i.e...drilled bonnet, wing vents etc...  :?:   Heat will only build up if it has nowhere to go.
Or am I way off the mark?  :?

[Xtremeteam]

on my 90 i fitted 200&300tdi wing vents so when stuck in a bog winching with the fans on the air has somewhere to escape & IMO looks neater than drilling the bonnet to [!Expletive Deleted!] :lol:

next stage for me is to wrap the manifold & turbo housing as the hotter the gasses are the faster they move so should reduce the back pressure slightly & give slight reduction in boost spiking,( in theory)

[isle of man]

i have a set of these........ http://www.genright.com/category.aspx?categoryID=117









peter henry