carbon bonnet

There's a few threads on this Chris if you have a search.

 

The heat repellant film stuff is what people use... You can buy it off ebay

 

Chris if I wasn't on mobile I'd find you the thread. Basically the heat stuff will prolong the life but still goes milky I'm looking into turbo blankets atm to reduce heat under the bonnet.

 

I fitted the reflect a gold when I had my bonnet replaced under warranty, I also fitted an engine cover too. It took longer for the bonnet to go milky and isn't as bad as the original but I feel traffic is the problem if I go for a drive nice and early get back the bonnet hasn't changed, sit in traffic for a journey get back and it's a noticeable difference. So just avoid traffic

Another thing I have noticed is the car's with a sports cat and de cat don't seem to suffer, a car I know had started to go years ago,owner fitted a sports cat and it's never got any worse and it was a really small area to start with.

I honestly think the only way to fully rid the problem is to buy a cazan bonnet, that's what im going to do then store the original.

 

TBH i'd be doing what chris said, try a turbo blanket, they seem to be the best at keeping the heat in the turbo!

 

I did the same as Ed when mine started to go but it hasn't stopped it getting worse. Interesting that yours is starting to go again already when Renault claim the replacement bonnets are from a different supplier. I looked into having mine replaced and they offered 60% of the £1800 cost but will only guarantee it for 12 months.

 

Be interesting to see how the turbo housing holds up to all the extra heat contained within it.

 

But the turbo's designed to withstand that heat, they can glow orange /white!
I wouldnt think it would cause any damage tbh, its not like its beeing quickly heat cycled from hot to cold or anything

 

Im fully aware how hot a turbo gets but if the blanket keeps it at upper temperature tolerance for the housing then it will shorten the life but who knows what the housings heat tolereance is.

 

Dan To give you an idea of what heat will do if your approaching the upper temp limit.
The limit for carbon steel is about 420 degree C, so say it will last 20,000hrs at this temperature if it goes only 10 degrees above you loose half it's life, so your down to 10,000!!!

 

I've removed the rubber strip below the windscreen, when hot you can see the heat escaping from under the bonnet, also fit some silver reflective tape to the under side of it too

 

Could be onto a winner here, agree with you Naith never seen one get worse once it's been decatted or had a sports cat fitted.

 

Removing the rubber strip must help

 

I think it's an absolute joke that firstly Renault see fit to charge £1800 for an inferior product and even worse if they have changed supplier and not addressed the issue at hand.

At £1800 they are having people's pants down, the reason it goes milky is because of incorrectly specified and cheap materials.

Next time Renault offer someone an insulting 60%, send them my way, they can have a bonnet that does the job and keep some nice change in their pocket.

 

If its cast iron, which they normally are it will be around 750C+ above this it may form cracks

 

You'd be mad to fit those turbo blankets imo harbouring all the turbos heat is just plain silly. I don't think there's any real cure for the milky bonnets it's just a poorly made carbon bonnet nothing you can do they all will fail