Turbo Blankets / Exhaust Wrap

I thought you wrapped the exhaust going into the turbo???

 

Cowpie explained it very well in a post in an old thread. By keeping the exhaust side of the turbo at a more stable temp, the gases "flow" better and actually lower your EGTs (pyrometer temp). So if you go with the theory that more efficient exhaust flow will then translate into your engine operating more efficiently. Now that doesnt mean you will see a MPG gain, but making your engine work less, to do the same job, certainly makes sense. The air side of the turbo to the CAC, A2A and then intake, actually gain by not being wrapped (insulated), so they can dissipate heat from the turbo air going into the engine.

 

I didn't wrap the flange pipe after the turbo on mine. Not a bad idea though, but the benefit might not be quite worth the trouble. I'll leave it to those that have done that to say whether it does or not.

Cetane pretty well covered it. As exhaust cools in the flow, it will flow slower and create somewhat of a choke point. If you can keep the exhaust flowing by not allowing it to cool too quickly, it maintains it's freer flowing characteristics, thereby allowing the exhaust to get out of the cylinders more quickly, which will in turn keep EGT's at a lower temp. It the restriction, that will cause increases in exhaust temp. This is why, to get the most efficiency, there needs to be a balance between exhaust temps, turbo boost, and having the engine at the proper RPM to both overcome restriction in rotational inertia and not over revving and using more fuel to get the same job done. If one can keep the exhaust flowing quickly, you also get a faster spool up on the turbo.

It sounds complicated, but it really isn't. That is another reason I ditched the waste gate turbo on my Detroit 60 for a BW non waste gated turbo. Just like we are talking about keeping the exhaust flowing by reducing restriction, having a waste gate turbo, in many ways, is like putting a nozzle on a garden hose. You get a faster flow on the output side by reducing the size of the orifice the exhaust has to move thru, but you create a restriction on the input side (the cylinders and exhaust manifold). That can drive EGT's up and efficiency down. Kind of a waste of a good engine. Now, to be fair, a waste gate turbo is not always a bad thing. If one is doing primarily local P&D kind of work, a waste gate turbo is actually beneficial. For primarily highway work, not so much.

 

This is more expensive, but the product holds up longer. http://www.atpwrap.com/

 

What adverse effects to the motor oil? Doesn't this promote oil coking? I run the southwest deserts and have concerns about the high temps generated within the insulated turbocharger.

 

Mr Haney, I`d like to get your advice on a turbo app. for my 4 1/4 B model. I`m a little confused reading all the threads on the subject. I would like to know how you would go and if you have it in stock. I`m new on the forum so I can`t pm you. Sorry if I hijacked this thread for a minute, but I seen Mr. Haney on this one.

 

Cold gasses are more dense. When the blanket is installed, it keeps the gasses hot. Hot gasses flow faster and they go through the turbo faster. With the increased airflow, EGTs are reduced in some strange physics way.

This works in the same way hotrodders use header wraps. The wraps keep the exhaust gasses hot so the gasses move faster out of the exhaust.

 

Why would you have any higher temps in the turbo at 115F ambient temp than you would at 32F ambient air temp? The temp in the turbo is related to the work the engine is doing, and any restriction in the exhaust flow. You can destroy a turbo at 32F just as easily as you can at 115F. I have crawled long pulls, in 100F+ heat with gross loads on, and never exceeded 900F on the EGT's. Oil coking? that hasn't been a real issue for a couple of decades now with modern oils we have.

See myth number 7
http://www.bankspower.com/techarticles/show/30-Turbo-Diesel-Fact-&-Fiction

 

Good question. You're safe from coking issues. Coking only occurs after shutting down hot, even then its very rare in a water cooled turbo. More so in a diesel turbo that doesn't see nearly the temps of its gas counterpart.