I do heat soak back tests at Garrett, and the hottest temperatures on the center housing are not steady state temperatures. On the GT40 I've tested, the bearing bores would spike up 300 C after about 6 minutes after hot shut down.

That being said, go ahead and coat your turbine housing and wrap it with a blanket (we do for some OEM applications) but just make sure you allow proper cool down before shut down.

Water cooling is the best for heat soak back, because the water absorbs much of the heat, and siphons more water in even after the water pump is turned off.

Kevin

 

Hi Kevin,

ah, just the info I was searching for. So you recommend driving the car off boost for a time before shutting down, and using a turbo timer to let it idle for a minute or so before shut down?

Also, I'm curious--what oem applications do you coat and use a blanket?

thanks!
Rich

 

I havent seen or heard of any problems using Polydyne coating. It actually extends the life of your turbo and anything else you want coated.

You would'nt be able to touch your manifold after running the car or anything like that, but you will see a major improvement in oil and water temps, as well as egt's.

I have my stationary gears, rotors, rotorhousings, turbine housing, manifold, downpipe and bearings coated. With this caoting you dont have to worry about build up, because it actually becomes part of the metal after it cures. With that being said, it wont chip off and ruin your compressor wheel or anything like that.


From Turblown's website

 

Rich,
A lot of OEM applications use blankets, or some sort of heat shield, but coated each turbine housing for an OEM with ceramic would be too costly to be worthwhile. Although the shielding improves turbine stage efficiency nominally, it is usually done to protect sensitive electronics.

Kevin

 

Did you compare heat soak back temps for blanketed vs unblanketed? It would be interesting to see how much difference the spike would be and if you can model effects on lifespan. WOuld you run the test just for the hell of it? If so, why not compare dry and wet CHRAs, too. Thanks!

 

A wrapped turbine housing will most likely hold the temperatures longer compared to the non wrapped one and not necessarily increase the peak, but you'll be fine if you just properly cool down the turbo before shut down.

Kevin

 

Wrapping the turbo with a custom blanket or shroud won't negatively affect it...period.

Asides from the benefits (cooler underhood temps, increased exhaust expansion, reduced turbo lag, etc) its actually one of the most overlooked upgrades.

...and before someone chimes in on how old this thread is (because it definitely warrants a review) or that wraps and coatings will make your **** rot - prove it.

I've yet to see a picture of a turbo, header, downpipe that was wrapped or coated show signs of degradation due to the added heat isolation. Trust me, I spent a few afternoons trying to find a picture showing this vs. the numerous threads of guys saying that it will even though they've never experienced it.

 

Glad someone brought this up.
I just ordered a blanket and DEI wrap to help with underhood temps.
Will I see a large improvement?

 

^i did

 

sorta skipped the conversation but my t78 was ceramic coated on the outside and had a heat blanket on it, you can now visibly see pieces of the ceramic coating flaking or missing.

it may have just been bad coating tho.

kevin.

 

I've said to heat coat the twin turbo manifold over five years ago and everyone said I was wrong. Typical answer even from friends and people that just llike to follow the majority (what are they doing with RX7's?) are if it worked it would a been done and I can't think for myself, duh. Quoting some people I know. The turbo manifold was actually tried even before I sugested it but the wrong stuff was used and it wasn't even 2k degree stuff (was on big thread). Jet Hot is not the best just most known. Their stuff flaked off my down pipe just installing it.

Anyhow getting sidetracked. The kermit stuff was used on engine internals on the 797B, correct? I had all my twin turbo stuff heat coated by a local place (excluding turbine manifold becuase I couldnt take it apart) and it all held up fine. If you can fford the coatings, go for it.

I think the thread is from the problem of mild steel being wrapped with header tape which holds in moisture and promotes rust. Well my HKS mild steel DP which was heat coated (jet hot) rusted within 6 months without any header wrap.

 

kevin, if you want your stuff properly ceramic coated (3600 degrees), let me know.

To update, I ended up installing the blanket recently on coated turbine housing. Underhood temps definitely went down, the jury is still out on potential after-effects. Based on the massive reduction in underhood temps, I think it was a good decision.

 

Thanks for the info.
My underhood temps with no blanket and wrap are causing my intake temps to climb pretty high sitting in traffic and at stoplights, so this was the info i needed.

 

The 2000-F Jet Hot coating on my downpipe still looks like day I put it on about 5 yrs/40,000 miles ago. Their 1300-F coating has held up well on my turbine housings, efini y-pipe, UIM and LIM.

I'm going single real soon and intend to use a blanket over a ceramic coated turbine housing.

Jack

 

i may take you up on that offer, the fd gets real hot under the hood.

kevin.

 

To comment on the efficiency (slightly...might be a bad comparsion)

On my 1/2 bridge TII, I was doing some initial break in/shake down driving near my shop here up and down our back road. With no hood

After driving around (albiet in vaccum) I noticed the intakes were quite cool compared to when I was running around stock (TMIC, stock turbo etc. now its full single, front mount, haltech etc.) but attributed it to the no hood factor.

Days later I was doing similar runs but boosting the car slightly, and ambient temp was a good 10 degrees (celcius) above the day I drove without a hood. And even with the hood on, there was no noticeable increase in underhood temps. Certainly nothing like that staunch, barbecue like, waft your face would be hit with when cracking the hood of a stock TII

Plus header wrap gets tha ladies ya know

Edit; BTW, Its not even a proper turbo blanket. I simply spliced some DEI header wrap in strips and tie-wired it around the turbine housing. Mani. and DP were wrapped (1 layer) also. I now have a speedmachine blanket which does an even better job (I can GRAB it instead of simply touch it)
And there is no coating whatsoever

 

Dude, you know for the ladies you are supposed to wrap the other head..er....

 

You should see a noticeable improvement of lowered under-hood temps. Also, the purpose of wraping the turbo is to isolate heat and keep the exhaust gases expanded longer. By doing that you actually are able to reduce turbo lag.

 

The wrap will help - for some extra protection for your intake checkout this wrap shield - (youtube clip, excuse the deutsch host) http://youtube.com/watch?v=qlU-r9IEaHM

 

The nicest and most functional "blankets" can be purchased from atpwrap.com. They are custom made to each application from insulated inconnel so you would have to send in your housing unless Tim already has done one of those housings. They build heat management shields for military applications as well as Champ Car and ALMS applications. They are a work of art and there is nothing better as far function and quality. I will have my downpipe and manifold/wastegate done very shortly for the ultimate in heat management.

 

gotta be honest with you as I don't think many people would want to send it in especially when it's pretty easy to make your own. DEI gives you more than enough material so even if you mess up you'll have plenty left over to try again.

 

I still like the gotham one the best. That thing is like a thick as diaper for the turbine side. No heat getting through that fat bastard

 

Funny you posted this Rich! I just ordered one this week and never even thought about it being an issue. I too have a ceramic coated turbine already. I can not imagine it voiding a warranty with Garrett since A-spec offers it as an option. I have to say from my last uncoated turbine to this coated one my under hood temps are still very hot!

 

Wow that looks like something you'd find in a NASA workshop.

Mind sharing what is it gonna cost you to get the housing, DP, and WG done?

 

You're comparing that crap to inconnel???? I think you had better do some reading on what inconnel is and the applications it's used for jr.

-J