Thread: Defender Heat and long distance driving

Originally Posted by AndyG

Save me a video of when you lap someone at Bathurst

Around the track or over the mountain?

Originally Posted by stewie110

What are the downsides of wrapped exhaust. Does the heat build up cause any damage or is it a null issue?

I did a fair bit of reading on this when I was considering it. I was particularly concerned about having it periodically wet/muddy/dirty and doing damage to the exhaust (or the wrap itself). I didn't ever find anything conclusive, but the general consensus appeared to be in favour of it being OK. There was some concern over the exhaust rusting, but from what I read the wrap itself would most likely deteriorate before the exhaust system in such conditions. Being a relatively cheap modification I felt that an OK compromise. However only time will tell (this is the first 4WD I've wrapped and it has only been three days).

I was never concerned about thermal damage in a Defender. As AndyG suggested, there's risk of damage if you wrap the headers (and particularly in high-performance vehicles), but we're definitely out of that league, and I haven't wrapped into the engine bay anyway (I doubt I'd get in there without pulling the vehicle to bits). You're also not wrapping the entire system from head to toe (or mouth to arse?), so there's a bit of "thermal relief" around the place (not a technical term, just my made-up opinion) to let some heat dissipate naturally. I've previously wrapped much higher performance vehicles and driven them like a moron with limited damage (to the exhaust, anyway), so I felt fine doing similar in a Defender (not the driving like a moron bit).

Some high-performance theorists suggest you should wrap the headers to keep the heat and exhaust speed high to improve scavenging, but I believe this does more harm than good (it often damages the headers) and opinions vary wildly (many header manufacturers won't warrant their stuff if it is wrapped). However these are all words that hardly apply in Defender-land (in my opinion) as this topic is actually about comfort rather than performance (although we do stress the vehicles a lot when off-road). Will it increase temperature in the engine bay by wrapping the middle bit? Maybe, but I figured it wasn't going to be too detrimental for my purposes (my opinion only).

From the firewall to the big muffler is an easy task and would cover most of your areas of concern (depending on 90 versus 110 and where it all is... I forgot to clarify that I did a 90 in my previous post - your wrap length will likely differ in a 110). There's a natural expansion-type point at the firewall where I started... well finished, actually - I wrapped from back to front, so the "leading edge" wasn't going to snag on stuff if I brush over it.

I will also wrap the next section from behind the big muffler to the rear muffler in the near future - this runs under the load space in my 90 and wrapping it will remove a lot of extra heat from this area (which is coincidentally right where my daughter sits). I don't wrap the mufflers. I'm not sure why - it's just habit. I never have and I don't think I've seen too many people who have either (in a car, anyway). There's probably a reason apart from aesthetics, but it's also perhaps another "thermal relief" area (maybe that term will catch on)... remember the heat has to go somewhere. Wrapping it keeps the heat inside and it has to come out the rear end eventually. Perhaps my rear mud flap will suffer the 90 melting problem now!

This has been one of my easiest and (relatively) cheapest installs - just take your time and you can get pretty good results. Look at the wrap before you start to apply it - the stuff I use has a more "secure" leading edge (it looks a bit like it has been overlocked) and a looser weaved trailing edge - getting the right bit on the outside helps to stop it fraying in my experience. You will also get some fibreglass on you but it's far better than working with insulation bats (I don't use gloves - I want to manhandle the wrap to get it nice and tight). I recommend wetting the wrap before install to aid in a nice, tight finish once it's dry. I'd also recommend getting wider wrap than I used (50 mm instead of 30 mm) to save some time and RSI from going around and around in circles (I just had some 30 mm left in the "shed"). I'll use 50 mm when I do the next section.

Originally Posted by AndyG

Save me a video of when you lap someone at Bathurst

I overtook some kid on a scooter does that count?

Kogvos,

Thanks for your post.

What make and size wrap did you use please?

Cheers,

Peter

Originally Posted by YOLO110

Kogvos,

Thanks for your post.

What make and size wrap did you use please?

Cheers,

Peter

I use Magma Wrap from Thermal Velocity. It's not as cheap as some but I've had good experience with it and I prefer it (I'm no expert, just an enthusiastic tinkerer).

Here is a picture of my Defender just done with 30 mm wrap. I'm really annoyed about that bad overlap about eights turns from the flange... I didn't notice it when applying and it's too late to do anything about it now... but looking back at the picture it's all I can see now!



But... I don't recommend using 30 mm wrap because it is quite narrow and takes longer to wrap (and is more fiddly as a result). I just had some from previous projects and used it up. I would use the 50 mm wrap instead (and will on my next section as I've now run out).

I also buy it in 10 metres rolls instead of 20 or 30 metres because I find it's easier to handle the smaller roll when lying on your back. But the longer lengths are obviously a lot more economical.

When you get to finishing your wrap, double the end over a bit so the loose strands are tucked underneath the wrap. You can either use stainless cable ties (which come with the stuff I buy) to secure it or hose clamps (which are easier to use, just not quite as sexy). I put cable ties on the start and end of my wrap (and anywhere I start a new roll - you may see a cable tie above the crossmember if you look closely in the above photo).