Guys, I already have my exhaust manifolds coated however my car is back in pieces so was going to do the hot side of the turbo.

I have heard that you shouldn't do the inside of the host side of the turbo. Can anyone confirm this.

Cheers,
Michael

 

You should not do the insides off anything pre-turbo. The coating may fail and come off damaging the turbine. Just do the out sides mate.

 

Hmm, so ceramic coating piston domes is bad?
Seems that piston crowns are pre-turbo.

Seen many snails coated outside "and" inside . If the coater properly cleans the parts and is competent , then there should be no issues.

But I would still recommend you query the professional opions from professional coaters. .such as Swaintech , jet hot , etc.

 

mine were only coated on the outside.

if you have room for turbo blankets, they work alot better

 

I have been told by a professional not to coat the inside of the housing, only the outside. Mine were already coated inside and out before I was told that, so I figured I would stick with it and see how it works.

The issue is the clearance between the turbine blades and the housing once the turbine blades heat up and expand. The housing also expands, but it takes longer due to the housing mass. Anyway, ceramic coating is fairly thin, so hopefully I won't have any issues (as I knock on wood). It will come down to how tight the tolerances are. Since my housings are cast, I'm hoping there is enough tolerance to allow for the ceramic coating.

As far as the comment not to ceramic coat anything before the turbo, I don't think this is an issue if the ceramic coating is applied by someone who knows what they are doing. It is not uncommon for pistons and exhaust ports to be ceramic coated.

 

I did inside out side of manis (pre turbo) but only the out side of the compressor, like Terry said I heard it can cause clearance issues so to be safe I just did the outside. Turbo blankets insulate heat better but they also trap the heat causing premature turbo failure....according to some theories!!

 

I was told by Jet-Hot to do the outsides only of anything pre-turbo because the coating can flake off over time and cause damage. They also said that if you do the housings on the turbos you will void any warranty you may have with a new kit.

 

One note here - my last motor had ceramic coated pistons, and I saw no indication of the ceramic coating flaking off when we dissasembled the motor.

 

Slightly OT but I had my manifolds, downpipes and hot side thermal coated. The shop doing the install called and the mating surfaces on the manifolds had been coated (where it meets the engine and wastegates), they told me I wouldn't get a good seal so they were going to machine those sections. I didn't even think of this, I figured the gaskets would make the seal.

 

We have used PolyDyn for all of our ceramic coatings and have never had an issue with the coating flaking off or anything. If we have a turbine section coated we usually take some really fine sandpaper and clearence the section where the turbine wheel is till it can spin freely again. Even then we usually never have to sand them at all.

I have my entire exhaust side coated from the heads all the way back to the tips of the exhaust. I had all my old IC piping coated on the outside and a teflon flow coating on the inside until I changed everything and just havent done anything with the new piping yet.

 

thanks for the responses but as suspected a mix bag of responses. My exhaust manifolds were done years ago inside and out but I will probe the shop about doing the outside only of the turbo and see what they say.

Another part which some say to do is the oil sump. I don't understand this as you don't want the heat to stay in the sump.

 

the sump? blah waste of money. you want the oil as hot as possible to easily out of the sump but coating wont do much.

 

Ok just got my pipe work back and they did only the outside for me. According to them they have had no complaints about it flaking but at the end of the day they didn't really know or care. In there eyes i'm paying so happy to do which ever.