: Polished Headers?

01-01-07, 04:31 PM
I know someone did this with the stock exhaust manifolds - think it was Marty (Lasstss) - but I was wondering if polished or extrude honed long tube headers would see any benefit. Whach'all think?

01-01-07, 04:38 PM
if they are long tubes...no benefit, its all in the design and collector configuration. There would really be no reason to do this except to smooth out imperfections due to inferior build quality.

01-01-07, 04:39 PM
Errr Never Mind

01-01-07, 04:47 PM
Right, I'm not really expecting polishing to be able to provide any benefits beyond the limits of the header design. But, like you mentioned, I'm wondering if the polishing, by taking out those surface imperfections within the tubes themselves, could provide better flow. So, anything to be gained here or move on?

And by imperfections, I mean just the general coarseness within the tubes, as well as visible ridges / scratches running parallel along the walls (usually along the bends).

01-01-07, 04:58 PM
the gains will be so small i think for you it would not be worth it, unless you can get it for free ! I know the ex-hone process can be costly. I have only seen this benefit the LS based DP race cars where they spend lots of money for a few HP and its all at the top end rpm at about 7200 when then go full out for a half a minute on the long straits.

01-01-07, 05:20 PM
My headers have the Cerma-Chrome coating on them, makes them look polished and is a nice thermal coating.


01-02-07, 05:32 PM
Polishing always gets you a 3% hp increase. Chrome is always good for 7%. I know this is true because I read it in the J. C. Whitney catalog!