Exhaust wrapping

[Stealer Of Souls]

Hi.

Been out of the game for a while (and wasn't that deep in the game to begin with).

Looking for people's experiences with various techniques to insulate the exhaust system.
I have tried a fibreglass wrap, which seemed to work well enough, but all it took was a couple of scraps (speed bumps and nasty steep driveways) and the stuff started to fall apart pretty badly. I have no idea how much survives on the car at the moment, but I think it pretty much upwrapped itself.

I'm mostly trying to keep some heat out of the cabin, when daily driving my poor passenger gets a serious case of hot foot and all that extra heat seems to build up since I don't have the most effective ventilation system (short of windows down at 100kph).

[d1 mule]

Exhaust wrap is shithouse,it holds moisture causing the exhaust to rust.

HPC coating is the goods but literally 10 times more expensive (based on prices on their website)

what about heat sheilds like stock stuff?

[Evlc36]

Procoat good - about half the price of HPC, and based on my last turbo build, holds up well - my manifold and other bits are currently getting coated by them.

[Mr Revhead]

How does coating work compared to wrap? I've heard a few say not as good.
To the point they wrapped over the coating.

[RomanV]

+1 to wrap sucks.

I've had:

wrapped exhaust (fell to bits pretty quick)

heat wrapped then wrapped in 1mm aluminium plate over the top/hoseclamped on (worked well to stop the wrap from deteriorating, but looked horey)

I've currenlty pulled off all of that junk, and am making up some under car heat shields.

Using 1mm aluminium plate spaced 5+mm away from the body with rivnuts and some threaded rod/nuts.

Stainless steel would be ideal, but just using what I've got.

Main issue is melting underseal and hot feet

[Evlc36]

I found it reduced temps really well in my prev build - prior the underbonnet temps were pretty insane and rooted the paint on my bonnet, afterwards it wasn't that hot when I opened the lid - and it looks awesome:

[d1 mule]

How does coating work compared to wrap? I've heard a few say not as good.
To the point they wrapped over the coating.

A mate pit crews for a Trans AM, prior ho HPC header temps were in the region of 850 C, after HPC 325 C

[KinLoud]

Hey there Lyndsay - long time no see!

Go with factory theories...
often a simple thin sheet of metal between floor and exhaust pipe -
An air gap either side of a thin metal sheet - in still air the "cold side" of the sheet will "float" at half the temp of the exhaust pipe.
With airflow for driving it will be even cooler.

Ken

[RomanV]

Also Altezza extractors are factory heat wrapped...

Lots of fibreglass crap but then encased in a stamped stainless steel cover to stop it from flying everywhere.

It does work, it just doesnt last long on its own.

[tractionfree]

you can buy an adhesive stainless steel tape to wrap over heatwrap if you want to give it a bit more protection. we use it on helicopter exhaust joints, its sharp as buggery though

[rollaholic]

Hey there Lyndsay - long time no see!

Go with factory theories...
often a simple thin sheet of metal between floor and exhaust pipe -
An air gap either side of a thin metal sheet - in still air the "cold side" of the sheet will "float" at half the temp of the exhaust pipe.
With airflow for driving it will be even cooler.

Ken

factory is good, but not always best. they do have budget constraints after all. (see - gold foil on mclaren)

[92mr2paddy]

ive got that carbon/titanium weave heatwrap on my downpipe and since then temps dropped alot and ive got stainless ties every 50mm to stop it unraveling,

i had the shit fibreglass stuff ages ago holding with hoseclamps, which just fell off and the wrap was shit too,

i say if you got decent wrap and proper ties the theres nothing wrong with it really, alot easier than making heatshields etc

[Mr Ree]

I have had the same heatwrap on my 2jz ever since I went na-t in 2008.

It is still just the way it was when I first wrapped everything, but then again, Im probably alot fussier than most people and spent an extremely long time getting it all as perfect as possible, and hence, it hasnt unwrapped or disintegrated.

I also wrapped everything after having it HPC coated.

[d1 mule]

I also wrapped everything after having it HPC coated.

That'll be why it hasn't disintegrated, has never got super hot.

[pc]

I painted my headers, wrapped them in fibreglass, then painted over that. Holds together fairly well... just not where stuff i've run over hits it or where the wire i was using to hold it on came loose and wore through it.
Not all fibreglass wrap is equal though. The first time I did it I used some loose weave crap and that didn't last long.

Wrapped headers are awesome if you have to stick you hands in the engine bay soon after using the car.

[Flannelman]

Soak the wrapping in water before starting. This lets the wrap stretch as it being applied. A few hose clamps here and there to hold it together so that the wrap can dry. In doing so it shrinks making it tighter on the pipe.

As a side note, there is nothing that can be put on the exhaust that will resist being punished by driveways or speed bumps.

[Stealer Of Souls]

Wow, I do not manage to get back on here often enough!

I think where it goes under the car I might look at getting heat shields between the floor pan and the car. It seems to me that this would be one of the better solutions since it is so difficult to prevent the odd scrapping.
My car is definitely not low, but that's still what ultimately killed the fibreglass wrap I previously had.
On a side note, the wrap was quite good on the exhaust header. Made a noticable different if you stuck your hand in the engine bay after driving. It also stopped the alarm siren from malfunctioning due to overheating (of course the real damage was done by then).

I remember now looking at HPC and Procoat, I think that'll be the header solution once I get a set of headers worth coating. Maybe some appropriately placed and shaped shields to further help limit the "apparent" temps when fishing around under the hood after a drive.

Hey there Lyndsay - long time no see!

Go with factory theories...
often a simple thin sheet of metal between floor and exhaust pipe -
An air gap either side of a thin metal sheet - in still air the "cold side" of the sheet will "float" at half the temp of the exhaust pipe.
With airflow for driving it will be even cooler.

Ken

Yeah it has been a while. I've been out of the loop with work and the car has been off the road in a holding pattern while I reclaim my garage!
Now that my garage is clear I have begun the resurrection process.

[Stott69]

Bazda has just priced me up getting Sinco manifold and dump pipe, then procoating it. Very reasonable prices, so hit him up if you decide to go that way

[Stealer Of Souls]

Bazda has just priced me up getting Sinco manifold and dump pipe, then procoating it. Very reasonable prices, so hit him up if you decide to go that way

How reasonable is reasonable? I remember Woolf mufflers in Auckland quoting around $300 for some very basic headers, that was some time ago though.

[Stott69]

Im getting 2jzgte twin scroll, so the price isn't comparable to what your after. Coating has been qouted at $180 for the maniflod