Absolutely!

OBX is the cheaper route, but you lose the heater. If you can't live without heat, go with SSI's!!!
I strongly recommend the Dynomax SS Ultra Flo or Welded Ultra Flow. They seem to me to be the best compromise of MAXIMUM air flow, without being obnoxiously loud! I'm surprised more Porsche guys don't go with it! You have to go to a muffler shop to have pipes custom made to match up the headers to the muffler, and a bracket for the muffler as well. That being said, the cost of a custom installation & Dynomax muffler is still cheaper than the purchase price of most after market "bolt-on" mufflers made specifically for the 911.

My understanding (perhaps others will correct me if I am wrong) is 1 5/8" header tubes is correct for your application. There are a lot of opinions about mufflers, crossovers etc.

Thanks guys, I was thinking about using the dynomax duel 2.5" in single 3" outlet muffler with the obxs, I just can't bring myself to cut my body up, and it would eliminate the need for a crossover or X/H pipe, do u think its too big for my setup? thanks again guys.

Andy

Just go with 2 in 2 out. one can go out where the OEM cut out is on the rear valance, and just point the other one down. I did this, and didn't need to cut up the valance. It all fits with LOTS of room!
That way, you can maximize the performance portion of the muffler!

Thank you again patrick, and you don't think the obxs are too big for my mildly built 3.0?

Andy

Anybody try to purchase a set of these lately? They seem to be NLA. No longer offered on eBay and vendors i've inquired with are "sold out"

I might have a set for sale Kevin that I'll give you a deal on - I have a set of 993 HE in my garage that I need to put on first (and get some stainless steel welded)

Thanks JD. No big rush by any means. My exhaust is fine for now with the cat bypass and dynomax 1 in 1 out i'll be hooking up soon. Just don't want to dyno my car with the "stock" setup & remap chip, and then have to dyno + remap again when I install le' headers.

Why the switch to the 993 exchangers? Better fitment + heat?

What would you need to do to use an O2 sensor with these, or any other headers? Are there O2 sensor fittings that could be either drilled, tapped and screwed in or welded in?

There are extension pipes that you can attach to these headers. The extensions allow you to use a factory-style dual-in "banana" muffler like the Dansk mufflers. In one of the extensions you can drill a hole and install an O2 sensor bung.

You can get the bung from places like here at Pelican

http://www.pelicanparts.com/catalog/shopcart/MISC/POR_MISC_INNOVT_pg14.htm

or Jeg's and Summit racing. But that's kinda silly to pay $8 for a bunghole and plug. You can go to the hardware store and get the appropriate sized metric nut (I think our sensor thread size is M18 x 1.5) and weld it atop a hole you drill in the pipe. And there you have your O2 sensor connection to the headers or extension pipe. If you choose to put the 02 on the headers, you should put it at the collection point and not on just one cylinder pipe.

They're baaaaaaaaacccccckkkkkk.......

http://cgi.ebay.com/ebaymotors/OBX-Exhaust-Manifold-Headers-for-65-89-Porsche-911-ALL_W0QQitemZ350069525217QQihZ022QQcategoryZ33631Q QssPageNameZWDVWQQrdZ1QQcmdZViewItem

The latest OBX option: http://cgi.ebay.com/ebaymotors/OBX-Racing-Header-Porsche-65-75-911-RSR-3-0L-Flat-6_W0QQcmdZViewItemQQ_trkparmsZ72Q3a552Q7c39Q3a1Q7c 66Q3a2Q7c65Q3a12Q7c240Q3a1318QQ_trksidZp3286Q2ec0Q 2em14QQhashZitem130246478877QQitemZ130246478877

The primaries on that system are NOT equal length and the mandrel bends are NOT one piece. How can they call this a performance header? At best it will duplicate stock.

Brian~ I respectfully disagree with your comment. Have you done any testing to back your claim?
With the installation of OBX Headers, a Dynamax 2 in 2 out muffler, and a SW Chip, I went from 208hp to 245 at the flywheel. This on a 167k mile 3.2 in my '85 Carrera. I now ride the bumpers of most 993,996's at my track of choice WSIR.

This isn't my claim, it's physics.
You are leaving torque on the table by not having equal length primaries. OBX and the like are simply cheap big tubes. Yes you will see a HP increase due to the larger ID tubing but they are not optimally tuned, which makes them similar to the factory exchangers in basic layout.

Looks like Patrick's seen a nice gain using them. Which headers do you prefer instead?

Everything out there is pure garbage right now. I wouln't put anything OBX makes on a Porsche. Does a big red "R" sticker come with those?

The standard for the industry is of course SSI, with equal length primaries and one-piece mandrel bent tubes (= no chance of failure). But those are on the smallish side ID for a performance engine over 3.2L in size.

The best large tube headers I have seen recently are made in-house by S-Car-Go. I don't recall seeing any that had heat exchangers though. You just are not going to get a tune tested quality product for $500. There is no free lunch. Yes, a larger ID than stock will make more peak HP but that's not all there is to be gained. How much of the gain is simply from the muffler and chip? Wong does great things with the computer.

The S-Car-go's that they advertise in excellence etc. are actually made in China by QSC. You can buy the same product from them. The do like quite nice - not sure if they are actually equal length though. They do have a nice collector, which is quite a step-up from the lower cost Bursch copy QSC headers they also sell.

I hope that those are not what I saw when I was at their shop. The units I looked at were made in-house (I was told) and ran over $2000. They looked like quality parts. Now if they are outsourced to China the same rule applies - QC is lost and the product is garbage.

You bring up a VERY good point. This is the dupe that many outfits are pulling now. Fabspeed is a good example. They do the R&D in-house and outsource to China leaving the impression that everything is made in their shop.

Having said all that, headers like OBX do have their place - as long as you truely know what you are getting. If that is what you want then all is good.

I have good results from these (although mine more closely resemble the ones from s-car go like QSC)

My belief which may be totally wrong is that the porsche headers are so short, that equal vs non equal is less important than on a v-8 or straight six.

I would use these over the B&B droning, equal length, made in the USA pieces o crap all day long.

BTW - I am tough on exhausts - I've had to had two MK mufflers repaired - and a dansk that I've knocked the stuffing out of (993 SS cams tend to run the mufflers hot) no issues with my POS OBX/QSC stainless Steel made in china headers.