TrevorS

iTrader: (1)

Sure, if you've hundreds of bucks, one can always buy a header, but another possible route, though to more modest gains, is porting the stock exhaust manifold. Has anybody done that? What did you think of your results?

Thanks -- Trevor

elcapetan

FAIL!!!!!

/thread

coryjames

omfg step one place knife in hand
step to fall onto it
step 3 die?

there will be no gain from this but if it makes you happy whatever the gain from getting a header is from the loss of the primary cat so no gain

TrevorS

iTrader: (1)

OK, so are either of these responses expected to make sense to me? If so, then gee willikers, I guess I missed out !

Could you possibly try again in language more intelligable to the common bumbler?

I know about porting, I know about cats, and I know about Delaware State required emissions inspections (they actually measure what comes out the pipe). Now, what were you saying?

Thanks !

DJ08tC

You will see minimal to no gains

rangerryda

iTrader: (1)

What they are saying is buy a header and keep your stock setup for the emissions testing time of the year. It honestly only takes about an hour to swap back to stock. I used to have to do things like that when I lived in MD. In FL, you can run straight pipe year round .Porting your head on the other hand may yield a few ponies but is not worth the effort if you are not boosted imo.

draxcaliber

seriously guys, it isn't worth calling him a fail and face palm and such. porting out OEM headers is a fairly common practice, especially when keeping a car OEM as you build or restore it. saw it on an episode of GEARS with stacy david (he is the friggan man btw!) he said you can port out and polish OEM headers if you wanna keep your build or restoration with original parts.

but the gains would be very marginal dude. like it was said before, the gains made with header swaps are from the loss of the header mostly.

has anybody done it? not that i've seen here, some people have gutted their header instead so they can still pass visual inspection.

scuds03

Only time you should port a header is if you are port-matching it to a ported head. End of discussion.

TrevorS

iTrader: (1)

I can see that argument, especially for a serious HP hound, but I'm not sure I'm personally that dedicated. I'd like to be able to eke out what gains I can w/o having to backtrack for the inspections.

Thanks !

One can gain by porting both at the head and the pipe flange, depending on the condition of the OE of course, and true, a head flange port works best when matching the head outlets, but depending on the OE manifold, it can be pretty rough/ragged up there, and that fights back when the piston is trying to push out the gases.

I'm guessing the bolded sentence above actually meant to refer to loss of the first cat.

I've read manufacturers started installing a first small cat simply becuase they heat up quickly and start scrubbing much sooner than a large second cat that acts like a heat sink. If that's really the purpose of the small cat in this case, it'd be interesting to know what the measured difference is in exhaust emissions between just the main Vs having both (at normal operating temps, of course).

Thanks again !

EDIT: OK, I'm seeing what you mean by saying most of the gain is probably from dropping out the first cat. The stock pipe is already a 4:1 header with the first cat comprising the base of it. Chances are there's very little that can be done to improve the head pipe interface and as for the base of the cat, it's just a standard pipe flange coupling. Oh, well, so much for that thought and thanks for the inputs !

draxcaliber

yeah, my bad about the bolded sentence. but yeah, i wouldn't of even known about this if i hadn't seen stacy david doing this on his restoration of an old jeep on GEARS, where he smoothed and ported out a set of dingy old OEM headers. made them look like new when he was done with them!

rangerryda

iTrader: (1)

You won't really be back-tracking, it's just a temporary option to appease the tree hugging states so that you can romp around on your merry way after getting your happy face sticker for the emissions year

TrevorS

iTrader: (1)

I love it !

Thanks guys, I appreciate your assistance. It didn't work out the way I'd hoped, but that's the reason to ask questions, right ? Once again, thanks much!

Very best -- Trevor !

TrevorS

iTrader: (1)

Thanks dude !

I just installed a second generation exhaust manifold and O2 sensor housing in my Eclipse and spent "quality" time porting both. I'm pleased with the results and followed up by porting the TB in my Scion. Results continued to be good and so I got hopeful about the exhaust manifold, but it seems that was a step too far ! Still, yes, in a bolt-on world, there is yet something to be said for the archaic art of porting !

Again, thanks dude, I appreciate your assist!