thermal coating on turbo...

[fullahotair]

When you guys speak of putting a thermal coating on your turbo, do you only apply the coating to the outside? or do some of you get the coating placed on the inside? does it affect tolerances? concern of the coating flaking? I have an TA33 and i am thinking of getting the exhaust elbow coated inside and out, but i wasn't sure about the rest of the turbo? Do i have to take the turbo apart and then take the exhaust housing to get coated? I haven't had a turbo apart, so i don't know what is involved in doing so. Does the exhaust housing come apart and assemble with ease??

Any thoughts/comments are welcomed.

Thanks,
Nathyn

 

[EMcNeice]

Nathyn,

I've been wondering the same thing. Every winter the exhaust housing rusts up on my turbo. I've never seen that side of a turbo coated before but i have seen the compressor housings coated. I would think thats the hottest part under the hood, especially when racing so i dunno if a hi temp coating would work. If you find out anything let me know!

 

[TRBON8R]

I too would love to find a coating that will last on the exhaust housing. I've got a nicely detailed motor and the one thing that ruins it is that rusty exhaust housing..... I can tell you, don't waste time with any of the high temp paints. I tried the high temp stuff from Eastwood. It looked great for about 2 months then turned to crap.

 

[Scott Atk]

The Black Satin 2000 degree coating works!! Its by Techline coatings and can be put on at home.

 

[fullahotair]

A local guy here in syracuse does ceramic coatings and such. He is goin to ceramic coat the inside and outside of the headers, downpipe, crossover, etc, with a black ceramic that is supposed to be able to withstand higher temps than the shiny stuff. He said he would coat all of those for about 200 bucks, so i think a small exhaust housing would be fairly inexpensive. I think the ceramic coating would work rather well. I don't know how much this coating varies from the stuff you can buy and do at home.


Nathyn

 

[disco stu]

I've been contemplating doing this, but I am not sure how well they can actually clean the inside of used exhaust components to ensure that the coating will stay where it belongs.

 

[fullahotair]

thats a good question. I am not certain how they would clean it, but if i were to guess, i would think they clean the parts in the same manner as a machine shop would clean a block or other greasy/dirty engine parts, which would be a "hot tank" type method - - just a guess though.

Nathyn

 

[Scott Atk]

Techline coatings specifies that you sandblast with low pressure (40 psi) to open the pores in the metal. They specifically say that you should not bead blast with glass bead as this closes the pores.

 

[sackracing]

my buddy just had his precison exhaust housing coated with 2000 degree black and it held up to 3 passes at the track great. cost him 100 bucks though.

 

[cool 84]

I've had the JetHot silver coating on mine inside and out for 5 years as well as a friend of mine and it still looks like the day it was done. If the coating will hold up on the headers, the turbo should be no problem.

 

[fullahotair]

thanks for responses, i am gonna take my goods to get coated in the next week or two.

Nathyn

 

[lazaris]

If the coating will hold up on the headers, the turbo should be no problem.

Although im sure the coating is holding up well, the turbine is the hottest point of the exh, more than the individual headers. So what works on the headers may not on the turbine housing. All 6 cyl's join there. If you have and EGT right before the turbine you'll see how much the temps drop if you unplug an injector during wot.

 

[sackracing]

jason cramer has his exhaust housing done in the 1300 coating i believe, there are pics on his website.

 

[norbs]

My turbo is coated with ceramic but two coats, guy said it would hold up to 1650 F. So far its held up to about 10 passes. But the spool up is alot better, i could feel the difference about 1 sec quicker spool up on the footbrake, well work the coating.

Here's a pic.


http://www3.sympatico.ca/norbz/motor_oct_2003.JPG

 

[cool 84]

Originally posted by lazaris
Although im sure the coating is holding up well, the turbine is the hottest point of the exh, more than the individual headers. So what works on the headers may not on the turbine housing. All 6 cyl's join there. If you have and EGT right before the turbine you'll see how much the temps drop if you unplug an injector during wot.

While I don't have an EGT guage, I've watched dynos and I know the headers get yellow in color while the turbo stays a dark red. I also know that after a few sustained runs my regular JetHot coating started flaking off the headers starting closest to the heads and less the farther away from the port. The crossover is fine, uppipe (it's a hotair car), and turbine housing look perfect.

Of course the EGTs at the turbine housing are going to fall off if you unplug an injector, you now have 5 cylinders pushing 1,600 degree air and one pushing warm air.

 

[chevyII]

That looks very clean,sweet. Just wondering where the breather lines go,catch can or v pump?

 

[lazaris]

Originally posted by cool 84
While I don't have an EGT guage, I've watched dynos and I know the headers get yellow in color while the turbo stays a dark red. I also know that after a few sustained runs my regular JetHot coating started flaking off the headers starting closest to the heads and less the farther away from the port. The crossover is fine, uppipe (it's a hotair car), and turbine housing look perfect.

Of course the EGTs at the turbine housing are going to fall off if you unplug an injector, you now have 5 cylinders pushing 1,600 degree air and one pushing warm air. [/QUOTE

I believe there was a post on what each individual cyl temp was for a before and after Power plate test. The temps at the headers were lower than what the exh housing see's. The cast iron housing may "look" different at wot because it because of its mass. The temp measured there however is still higher than the individual header pipes. It appears most people have harder time keeping the coating on the housing than the header.

 

[cool 84]

Interesting. I believe you since you have data and I don't but it's hard to understand. I can understand the turbine wheel being hotter but how can the housing be hotter? The exact same coating on the housing looks just like the day it was installed and the headers look like crap but get better the farther from the exhaust port. Not arguing but maybe someone can explain this to me. I understand because of it's mass it doesn't heat up as quick and doesn't cool down as quick but with it being farther away from the exhaust ports than the headers, how can it actually be hotter? Are you talking about the inside surface of the housing?

 

[jetmech]

I saw the 62 biscayne at rad rides by troy when we went to the unvieling of the 67 ebay
mustang and the turbine housings were coated silver on that car. the engine is a smalll
block twin turbo w/ 1200 hp, and the car did the hot rod power tour. the exhaust housing
looked beautiful. I called them to ask were it was done. they use a place in Steger Illinois
called Coating Specialties usually a 2 day turn around. Then use a die grinder to smooth
the housing out and then coat it. I forgot to call today but will try and call tommorrow
for a price on coating my new gt-61 housing. number is.708-754-3311, rad rods said they
use HPC coating. you can go to hpc's website and see the results.

 

[lazaris]

Originally posted by cool 84
Interesting. I believe you since you have data and I don't but it's hard to understand. I can understand the turbine wheel being hotter but how can the housing be hotter? The exact same coating on the housing looks just like the day it was installed and the headers look like crap but get better the farther from the exhaust port. Not arguing but maybe someone can explain this to me. I understand because of it's mass it doesn't heat up as quick and doesn't cool down as quick but with it being farther away from the exhaust ports than the headers, how can it actually be hotter? Are you talking about the inside surface of the housing?

By no means do I think your arguing. We are just discussing and sharing information. Maybe the housing being the thickness that it is helps keep the coating on by disapating more heat. I've always read guys had trouble keeping it on the housings.