16 replies to this topic

[Paulus H]

Hi folks, can anyone advise me the advantages of wrapping the exhaust manifold. I have a Tullet and since fitting the boot area has been like a turkey roaster! It makes me think the engine bay temps have gone up accordingly, however I wonder if this is really a problem or not. The inlet pipe for my induction butts up against the grill (no ears on my car) so I would guess I am getting ambient intake air. My thinking is a wrapped manifold will be hotter internally and might cause the exhaust valves to run hotter. Any sensible advice would be appreciated. Kind regards, Paul

[techieboy]

Just fit better quality heatshielding to the engine side of the boot bulkhead to prevent the heat passing through. The original stuff is liable to melt with a stainless manifold. I replaced mine with Nimbus about 5 years ago when MartinS' melted and there's negligible heat in the boot. I've also removed the foam pad with the heatshield coating on, from underneath the boot carpet (the precious inch it frees up means a crash helmet can fit comfortably now) and have no heat issues, even with the supercharger and 3" Tullet system.

[FLD]

Another vote for nimbus here. 

[fiveoclock]

Just remember that if you wrap the manifold/exhaust the heat has to go somewhere else and can cause burn/heat issues further down the system

[fezzasus]

Have you asked Tullet?

[siztenboots]

do you have a cat exhaust , have you checked your lambda / manifold for leaks.

[TFD]

Stainless steel manifolds (So not OEM cast ones..) are heatwrapped to keep the heat "inside" wich results in a higher flowspeed in the manifold. Cast ones have more mass/heavier so they keep heat in much easier.

 

That's the technical theory. I never felt a real difference in spoolup heatwraped or not. Heatwrapping is a nice thing when you dont want to melt everything down or need to put your hand in a hot enginebay.

 

I would do it in a VX whit an aftermarket manifold.

[Paulus H]

I was also wondering whether my one remaining CAT would work better (less emisions) with more heat going through it?

 

Kindly, Paul

Edited by Paulus H, 07 November 2014 - 10:16 AM.

[Rosssco]

Another vote for a decent heat shield. Get rid of the crappy foamy stuff, which can, like my previous one, detatch itself and touch the exposed manifold, consequently going on fire and nearly melting the whole car on Courtenay's dyno..

 

With a sheet of nimbus installed (2 /3 holes in the rear clam for bolts, and leave a small air gap between the nimbus and the boot wall, use washers if necessary), it was no hotter than before, despite an exposed Tullet manifold..

 

You can also apply some of that adhesive, reflective insulation on the boot wall before the nimbus.

Edited by Rosssco, 07 November 2014 - 10:26 AM.

[fezzasus]

I was also wondering whether my one remaining CAT would work better (less emisions) with more heat going through it?

 

Kindly, Paul

 

Too much heat and you risk melting it.

[Nev]

I'd advocate exhaust wrap over Nimbus wherever possible, because: 1/ If you use exhaust wrap it contains the heat in the pipework, thus keeping the engine bay temps down. This is the key reason to use it IMO. 2/ It doesn't rattle. 3/ It doesn't bend/break over time. Critical hot things like manifolds can be double wrapped and it really makes a significant difference. The thing about using Nimbus is that you have already allowed the heat to escape, and all the Nimbus does is refelect that excaped heat somewhere else. ie it is a retro-active solution, where as exhaust wrap stops the problem at source and forces the heat out of the back of the exhaust (where it should go). I have been using exhaust wrap on my car for the last 5 years at least, I don't need to use any heat shielding at all around my turbo or exhaust manifold what so ever. I have completely eliminated the chimney above the exhaust manifold, the delicate brackets around the engine mount shields and gear cable shields, all without any heat problems. QED.

Edited by Nev, 10 November 2014 - 08:59 AM.

[Chris P Duck]

Not so sure about wrapping if your car is out in the rain a lot. It soaks up the water and steams like a bitch when you start it and it heats up (have honestly had 4 people stop me to say my car is on fire). Guess that's not a major issue as long as you're aware of it but it does concern me that the wet wrap is being held against the metal for extended periods... I'm sure that'll shorten the life of the manifold significantly.

[Paulus H]

I'd advocate exhaust wrap over Nimbus wherever possible, because: 1/ If you use exhaust wrap it contains the heat in the pipework, thus keeping the engine bay temps down. This is the key reason to use it IMO. 2/ It doesn't rattle. 3/ It doesn't bend/break over time. Critical hot things like manifolds can be double wrapped and it really makes a significant difference. The thing about using Nimbus is that you have already allowed the heat to escape, and all the Nimbus does is refelect that excaped heat somewhere else. ie it is a retro-active solution, where as exhaust wrap stops the problem at source and forces the heat out of the back of the exhaust (where it should go). I have been using exhaust wrap on my car for the last 5 years at least, I don't need to use any heat shielding at all around my turbo or exhaust manifold what so ever. I have completely eliminated the chimney above the exhaust manifold, the delicate brackets around the engine mount shields and gear cable shields, all without any heat problems. QED.

Thanks Nev, do you have any advice as the best practices for wrapping? I have never considered this on any of my previous cars but the Tullet really heats up the engine bay and if there are no tangiable downsides I am inclinded to give it a go. Thanks for your advice, Paul

[FLD]

Damp it before using it as it makes it more flexible / easier to apply.  Allow for a 50% overlap as you wrap which will result in a double layering.  Use plenty of stainless tie wraps to hold it all on!

[Paulus H]

Damp it before using it as it makes it more flexible / easier to apply.  Allow for a 50% overlap as you wrap which will result in a double layering.  Use plenty of stainless tie wraps to hold it all on!

 

Dude that was exactly the kind of advise I was looking for thanks!

 

Paul

[slindborg]

and if you go for the spray stuff that you apply after its wrapped, make sure you get some sort of PROPER spraying mask to wear as I did a manifold with it and was wearing a 2K compatible mask and I could still smell the solvents from the wrap spray.

 

Did make it last longer though.

[Nev]

Damp it before using it as it makes it more flexible / easier to apply.  Allow for a 50% overlap as you wrap which will result in a double layering.  Use plenty of stainless tie wraps to hold it all on!

Yes, exactly this. I have never used the spray after wrapping, but I can only think it would help prolong it's life too.