Stavros

I know the story always has been not to heat wrap turbo exhaust manifolds and turbine housings as they crack/melt, but who has experienced that?

Just wondering if its as realistic as "run without a dumpvalve and your turbo dies really quick".

See a lot of foriegn turbo cars running them with seemingly no issue

I do know personally of one car that fucked the manifold because of it, but only one.

jr

Ive seen a few downpipes that have failed because of cracks that was put down to the wrapping itself

Stavros

I was always under the impression downpipes were safe, lol, ive always wrapped downpipes, my cossie one was wrapped and never failed even with antilag!

nilrem

not seen one... it could just be the same a s the DV issue... that it wont make a big difference until you are running high boost on a high performance engine... and then i bet its only in race situations, like rally or something

jr

proberly so many factors in why some are fine and some arent, both ones ive seen fo were on high power s2's not that that really matters

Hardeep_Singh

my old turbo housing, manifold, and downpipe were all wrapped and there been occasions when i have ripped the motor so hard all the above have glowd red hot and i have never had any cracks appear!

Stavros

The driftworks S14a is a good example too, just like yours, all wrapped, running about 450bhp and abuse much harder than 99% of cars on here im sure, and never had a problem at all.

Also running about 1.5bar on a GT3071R with no dumpvalve either and had no issues with that breaking either.

Seems to me its worth a try.

Rick

For me, it's about maximising reliability. I woud not run a t34 at 2 bar without a dumpvalve, the shock loadings CANNOT be doing it any good, Sticker Paul snapped a shaft on his recently - would that have happened with some way to release the pressure?

Hot manifolds are bad, they are more prone to cracking than when run cooler. Not to mention the increased EGT's with the additional loading on the exhaust valve and piston that this brings. So, if you know it's bad - why do it?

In competition, every last half a hp counts, and there are arguments to say that the increased energy in the exhaust will spin up the turbo faster etc - but 99% aren't in competition, and want to have fun.

It's all very well saying "i ran it on mine and it was ok" - but that proves nothing. Take 100 cars with wrapped manifolds, and 100 without, run them for 100k miles and study the results - that should tell you something. That isn't practical though, so the next best thing i to rely on science theory to guide us - u'd be foolish to go against it IMVHO.

Stavros

But what about the improvment in spoolup, exhaust gas extraction, etc etc etc a more efficient (ie heat wrapped) exhaust side will give?

What about the differences not having all the heat radiated into the other parts of the engine (head especially) will give?

IIRC even rod commented that just his turbine housing blanket made a noticable difference.

There 2 sides to the argument.

Garage19

I would have thought that the science behind it would be that the turbine is driven by the kinetic energy of the exhaust gases. Losing any of that energy by letting it heat up the atmosphere will loose performance.

So on a purely performance point of view it is best to keep as much heat within that manifold as possible.

The only thing that limits this is the properties of the materials available.

The construction method of your manifold will also come under particular questioning. If it is a fabricated item things like post weld heat treatment and careful fabrication in the first place can help prevent cracking. I find sometimes you can predict the way a manifold will grow/expand and make allowances for it in the design.

Rick

Less heat is radiated, and this is a big plus - i am REALLY tempted to wrap mine because of how close it is to the radiator, plug leads, water hose..

Forget about radiating heat into the head - the manifold is bolted to the head - and when wrapped is much hotter - far more heat is transferred by conduction than by radiation - hence the head temperature is increased with a wrapped manifold, along with EGT's. Std ford turbo manifolds have high nickel content in them - i wouldnt be worried about them cracking, for me the danger is increased thermal loadings on the head/valve/piston/plug. With tubular steel, which is very thin, then the cracking risk is much greater.

I don't doubt that wrapping will help spool up - my own car after being driven hard for a couple of minutes and the turbo is beginning to glow, that it spools up noticeably faster. Less energy is now lost from the gas and so helps drive the turbo. However, reliability is no1 for me, and would rather prolong engine and turbo life rather than have that extra edge. If i was competing then things are totally different, pushing things to the limit with big budgets needed.

In the end, u have to decide for yourself if it's worth it to you.

Stavros

Theres no denying there is more stress on certain components.

But like with dumpvalves and fookin countless other mods people reccomend or shy away from, theory and reality are two different things.

Ie without a DV causes more stress and load, but the odds of one failing because of no DV is still absolutley tiny compared to what it seems on paper.

And it may be the same in this case too.

Hence me asking this question about people EXPERIENCE in it, rather than asking their opinions on the theory of it....

Rick

Yea, there is no argument there at all - wrapping will help spool up. The question is - are you willing to accept the incrased risks to reliability that this brings?

Stavros

see above tho. HOW much? we dont know.

hence why i DIDNT ask for an argument in the theory of this, just experience of this, as theory means fuck all in cars, we all mustve realised that by now.

Butch.

iTrader: (1)

i had a cossie which had the manifold and turbo wrapped with heat wrap and it use to smoke on over run quite badly then i removed the heat wrap it was fine didnt smoke on over run.............

Rick

Steve, i realise you are asking about experience, but I really dont think this is going to tell you anything - as there are far too few people to be able to draw any kind of conclusion.

I set up an RST the other week with a heat wrapped manifold - the car is totally std though, runs 11.5:1 at 7psi - that car is never going to melt. So if he came on here, and said "yea, im wrapped, never had a prob" - what use is it? Not a lot. Ok, thats an extreme example, but in order for statistics to help you with an engineering matter - you need a lot of them - and we have got maybe a handful....

Stavros

Its not going to tell me a lot.

But IMO a lot more than theory ever will.

Rick

We DON'T know - i totally agree. Theory DOES mean a lot - it's just how you apply it, very few people are skilled enough in the field to apply it properly. I'm with you thought that tests tests tests is what counts - it's just no way i can afford to do it! So rather than relying on half baked experiences, i try and use the theory as best i can - unless something is obvious - ie EVRERYONE runs their t4 of the compressor map - but they still seem to hold together...

Stavros

exactly mate, there is SO much that people say not to do, what in internet typing and looking at it seems absolute madness, but in reality the downsides of it are incredibly small compared to how they seem.

T4s at mega boost, the destructive abilites of ALS, the destructive abilites of no DV, cone filters sucking in hot air (NOT on rollers!), not running water cooling on turbos (on that note, there a LOT of GT series turbos running with no DV or water cooling, both are seemingly madness, but no harm yet, and its been a few years...), and quite possibly, the heat wrapping thing too.

All of these things shorten lives, but usually something more fundamental and common has made the item break way before these things fuck it!

Rick

When i get my own Dyno farm we'll put all this to the test - 10 engines with wrap, 10 without - all running 40psi on a t3

Thing is, at the mo i insist on driving a 15 year old escort, and if it doesn't get me to my finals on tuesday morning, i'm screwed