Heat Shield vs. Turbo Bag

[thom_77]

My engine doesn't have the turbo heat shield on it, and I was thinking about having one installed now that I have the new turbo on there.

In poking around the internet, however, I've found heat shield 'bags' for the T3 that wrap around the hot side of the turbo, which help keep engine bay temperatures down and also apparently have the added benefit of helping the turbo keep the cool side cooler and making the it spool faster (although I don't see how that is possible).

Anyone have any experience with these things? The average price is around $150 and they don't require any real installation (they're fitted for the T3 and close with velcro or snaps).

[Jonathan]

Considered this myself as the heat from the turbo downpipe commonly causes the zinc to corrode on the chassis - I've seen many examples of holes in the chassis next to the turbo.

I've recently wrapped heat material around the downpipe - turbo outlet to cat - to see what difference it makes (little).

I know on the later cars the turbo is also air cooled (from the left hand side ear) so bagging it is not probably a good idea, the concept is to contain the heat in the gas, which moves quicker.

I believe one chap in Hong kong done a turbo /header wrap and said it was a difference in performance.

Whether you should do it or not...I dont know, there have been discussions on it as well on here and again usually draws a blank.

[trackmagic]

Tom,

I have one from DEI still sitting on the shelf. When I rebuilt my engine I went with the thermal barrier coating which is working very good and so just been slow to putting the bag on. My thoughts on why you might want one is to keep the engine compartment temps down, especially if you drive it hard and live in a warm climate.

Best,

Jeff

[rogerch]

Physics says if you don’t dissipate the heat it will build up, so I guess a turbo bag would mean the turbo itself will run hotter, I have no idea as to the effects of this on an Esprit, but I’d be finding out before fitting one.

Low temp day today, 0.9 bar wow we wus flyin’

[Bibs]

Running hotter is a good thing Roger.

[vauts1800]

I agree with Roger, Heat is good, it is what makes the Turbo spin. containing the heat inside the exhaust side of the turbo should make the heat go out the tail pipe.

[jonwat]

I've read that lagging the turbo to keep it hotter means it stays hotter for longer after switching off & is more likely to heat up & carbonise the oil inside it. Not good.

[mchlrodrigues]

I've got one fitted and I wrapped the wastegate discharge as well. They do make a tremendous difference in engine compartment temperature, but the materials don't last. The turbo blanket will smoke for about an hour when first installed as about 0.5" of the ceramic packing closest to the housing turns to ash. After the initial "burn in" wear is much slower, but after 18 months or so depending upon how hard the car is driven the thread holding it together will burn up and the blanket will begin to fall apart. Any metal touching the outside of the blanket, such as an O2 sensor, will burn through as well with time.

Standard header wrap will burn up in a couple of months if the car is driven hard.

I've recently bought a new blanket, which is supposed to withstand 1800oF continuous, called a Lava Shield, by Heat Shield Products.

http://store.newlevelmotorsports.com/helafituhesh.html

It's considerably thinner and is unlikely to reduce heat in the engine compartment as well as the first one, but hopefully it'll hold up. I also bought some new header wrap called Inferno Wrap, also from HSP supposedly good for 2000F continuous.

I've yet to fit either so I can't say whether they'll live up to their reputation. My car has a water cooled ball bearing turbo; I've had no reliability issues, but I can't say what might happen with an old air-cooled plain bearing T3.

[MrDangerUS]

Sometimes you can find an answer at the “Stevens” site, same car =same problems

http://www.thelotusforums.com/forums/index.php/topic/22242-heat-shield-templates/

http://www.thelotusforums.com/forums/index.php/topic/13941-turbo-shield/