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Lets talk 'Heat Wrapping'


Brazil

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I would like to have your views and opinions on heat wrapping as its such a grey area and there's so much mixed opinion on this subject.

 

FYI: I am using a HKS T04Z full turbo kit, and with supporting mods I am going to try and push 750bhp

 

Positive views I've read:

 

More heat equals more flow,wich equals more power,you run a turbo beani, heat wrap your manifold and dump pipe and i guarantee you will get some power gains and your engine bay temps will drop dramatically.

 

Negative Views:

 

Increased residual heat in the exhaust ports and manifold, due to the wrap, the exhaust valve temperature increases, so any unburnt air-fuel mixture in the camber after ignition and exhaustion of the gases is ignited from the higher temp.

 

There is more to be worried about then just manifold damage. I experienced detonation when readily when i had a wrapped exhaust.

 

I've also read a lot that heat coating has very little effect and doesn't work as good as the wrapping material.

Edited by Brazil (see edit history)
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I've always had everything I can heat protected the best i can, never had any negative sides IMO, my cars have always made good power for the spec.

 

I've read that the wrap is not advisable on all manifolds; but the Whifbitz kit is heavy wearing and there is little chances of getting damaged due to the heat wrapping. Could the same be said about my HKS T04Z turbo kit?

 

Is Jamesy's Do-Luck, heat wrapped?

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depends on the grade of coating you get, friend of mine had his manifold and downpipe done on his MR2 and wasn't too bad

 

If you get the equivalent layer zircotec coating to wrap it is expensive, I had my LS7 runners and downpipes coated along with the BW turbo hot sides and it cost £1800

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When you add horsepower to an engine, one side effect is added heat generation. Most engines are designed to operate at 80-85Celsius, however the exhaust gasses that leave the engine can easily be over ten times hotter than that, and it's common for turbo exhaust manifolds and exhaust downpipe to sit right up against the engine. When you have something that is 1000 degrees about two inches away from something you're trying to keep at 80-85 degrees, it's just common sense to use some kind of insulation.

 

Chapter 10: exhaust manifold design

Maximum boost Designing, Testing and Installing Turbocharger systems by Corky Bell is an nice book which describes heat management in detail.

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Can wrapping a tubular manifold contribute to it cracking, do you think?

 

It will crack a cheap (thin guage)manifold for sure.im using a boostlogic manifold and am going to wrapping it,anything heavy guage or steam pipe will be fine ,but you should always check your egt

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Can wrapping a tubular manifold contribute to it cracking, do you think?

 

Possibly, poor design and weld can fail from the added heat retention, although in my experience if it fails with wrap it would have failed without

 

A well designed manifold with good quality stable metal usually expands and contracts within its stress limits

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My hks mani was wrapped, it cracked in 2 places, ive had it repaired and left the wrap off, time will tell if it cracks again, btw ive now braced the turbo to try and help.

 

Ohh, I was hoping not to hear any negative about the HKS manifold.c

 

Where did it crack? Is there a way that I can modify it so it will be tougher?

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When you add horsepower to an engine, one side effect is added heat generation. Most engines are designed to operate at 80-85Celsius, however the exhaust gasses that leave the engine can easily be over ten times hotter than that, and it's common for turbo exhaust manifolds and exhaust downpipe to sit right up against the engine. When you have something that is 1000 degrees about two inches away from something you're trying to keep at 80-85 degrees, it's just common sense to use some kind of insulation.

 

Chapter 10: exhaust manifold design

Maximum boost Designing, Testing and Installing Turbocharger systems by Corky Bell is an nice book which describes heat management in detail.

 

That's for explaining mate. :)

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It will crack a cheap (thin guage)manifold for sure.im using a boostlogic manifold and am going to wrapping it,anything heavy guage or steam pipe will be fine ,but you should always check your egt

 

I too have a BL manifold, it's unwrapped and has been in place since about 2004 with no cracks. My EGT probe is in the collector, so it'd soon show up the increase in gas temps, didn't think of that, thanks :) Might even improve spool due to more heat energy hitting the turbo. I've got performance graphs of it unwrapped so I might have to wrap it and do some testing...

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Can wrapping a tubular manifold contribute to it cracking, do you think?

 

Absolutely, the junk most commercially produced kits use, material wise, needs all the help it can get. Forget wrapping and coating, spend the £££'s making proper supports for the turbo and wastegate instead. Ensure the manifold to head flange can expand and contract on the head, with oversize bolt holes, correct washers and nuts, and a multi layer shim gasket(s). The manifold may need slitting vertically on the flange to make it into two or three short sections, that can individually move about. You can do a LOT yourself to make up for the serious shortcomings of the manufacturer. 9 month old Trust manifold on RB26, after several attempts to repair chronic cracking by what appears to be the local blacksmith

Edited by Chris Wilson (see edit history)
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I've braced mine, with that much weight it seemed crazy not to, also I run a flexi section on the downpipe

Same here.

Absolutely, the junk most commercially produced kits use, material wise, needs all the help it can get. Forget wrapping and coating, spend the £££'s making proper supports for the turbo and wastegate instead. Ensure the manifold to head flange can expand and contract on the head, with oversize bolt holes, correct washers and nuts, and a multi layer shim gasket(s). The manifold may need slitting vertically on the flange to make it into two or three short sections, that can individually move about. You can do a LOT yourself to make up for the serious shortcomings of the manufacturer. 9 month old Trust manifold on RB26, after several attempts to repair chronic cracking by what appears to be the local blacksmith

Nice welding!!

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