Gen II exhaust manifold/header: thermal coating/porting questions. . .

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My engine mounts are shot. I am taking Dave's advice and going at them from the top.

But since I am going through all the work to remove the factory manifolds, I might as well get my money/time's worth.

On my GT35R STi I noticed some significant changes by thermally coating the SS header; lower engine temps & quicker spool.
Now I know that the temperature staying condensed in the pipe moves the exhaust more quickly. So the plus of lowering under hood temps is great (will probably do side pipes too).
Beyond the lower engine bay temps, I am wondering if there will be a noticeable gain from the more-quickly moving gasses from our great flowing heads ( )?

Next, is it possible to port-match the manifolds to the heads? I really know nothing about the manifolds. Are they more restrictive than the stock heads can flow or the opposite?

Searching really didn't have many results for the info I'm looking for.

Thanks,
Nick

 

[Steve-Indy]

Hi, Nick. I really don't know enough about thermodynamics to answer your question...BUT, that fact did not stop us from an experiment or two a while back. You may want to read the thread...and follow the link to Ron's post:

http://forums.viperclub.org/rt-10-g...ramic-coating-entire-exhaust.html#post2321806

You should drop down to Viper Days in June at Ginge Man.

 

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Thanks for the link & the invite Steve.

Another IN/KY member tried a variation of this process on his 2001 Viper...coating everything from the Belanger headers, collectors, high flow cats, and first section of the 3" Corsa cat-back exhaust...which did move the heat rearward...giving the "hot tail pipe". After a 50 mile drive in his 2001 and my 2001 side by side( mine being stock except for a Corsa cat-back system) we stopped and measured the exhaust gas temps at idle...and the coated system's readings were over 100 degrees higher...NOT a "good" in our opinion. When we later dynoed his car, it had a lower than expected HP as well for a "creampuff". Needless to say, we did not try any other extra coatings.

Again, thank's Steve for great input.
This result is the important info I was looking for. Since exhaust flow is increased with higher temps, coating the entire exhaust (headers, sills, cbe) should create enough heat to essentially make the exhaust system less restrictive.

Nick