23 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHHeader ports need to match gaskets perfect?
Leading reported evidence
Test 3.6l only
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
Their reason...Their 3.6l headers were designed and tested for the 3.6l only.
Leading evidence: 'Test 3.6l only' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check ports' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion · Original poster
I wish I had at least a performance box to run the same length of road and compare a before and after.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
Actually, IMHO, I would only recommend AWE or Cargraphic headers as their products are designed, tuned and performance tested for each specific engine application.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
Both AWE and Cargraphic design and test their products for tuned perfomance....
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
Actually, IMHO, I would only recommend AWE or Cargraphic headers as their products are designed, tuned and performance tested for each specific engine application.
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
23 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
0 acknowledgements have no verified action link; they do not establish a repair result.
Generation: 20261027T154520Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
How important is it for the header ports to match the gaskets? I've pretty much done everything I can short of going FI except for headers. I've looked at as many company headers as I could and finally purchased some headers. Everything looks very good except the header ports are a little smaller than the openings on the gaskets. How crucial is this? Go ahead and port match them?
I've traced around with a black marker where the gasket is. It's only a few mm's off. I haven't removed the OEM headers to see if they match the head openings but I'm assuming the gasket matches the head openings as they are OEM gaskets. I'm not sure how fabspeed gaskets are going to help as they should have the same opening size gaskets.
Bc they probably are. Thats why the ports are smaller. From searching those headers will cost you 13hp. Best thing to do is grind out the inner welds on the oem headers and weld the outter side to build up the metal bc grinding them will go through the runner wall. If you want to spend the money for headers then get the fabspeeds or B&B ones.
Actually, IMHO, I would only recommend AWE or Cargraphic headers as their products are designed, tuned and performance tested for each specific engine application. But with that said, headers really are not going to do much for your car and if they are designed wrong (as stated above) you will actually lose torque and HP....
Original gasgets have bigger holes than the actual port in the head.
So check the ports before you do anything.
I bought a set of e-bay headers, and problem with those were that the holes in the flange were way too big.
Payed 90usd shipped, so it wasn't very expensive. If I have the time and the motivation, I might make new flanges and some minor modification to those...
These are actually Ztek headers not the ebay ones. The reason I chose this company over the other ones is mostly because of the amount of welds. All 3 pipes are one piece unlike all ebay and even some other name brand headers. Most headers I've seen are made of 2 separate pipes welded together for the shortest pipe. From flanage to flange, the header is only 3 piece/3 areas welded where as the other ones are constructed from 4-6 pieces welded together. I hope that makes sense.
Those do look better but that doesnt really mean much. Atleast those dont tapper right after the flange like the ebay ones. These do have the same amount of parts/welds as the ebay ones do.
I know awe is top notch. Havent read anything on the cargraphics yet. I was simply going off what I found with good dyno results and those two was what everyone was praising.
Both AWE and Cargraphic design and test their products for tuned perfomance.... As an example, AWE does not make headers for the 3.4l 996 and they will not sell you the ones they do make for the 3.6l for installation on the 3.4l. Their reason...Their 3.6l headers were designed and tested for the 3.6l only. Their design is for speciifc performance parameters while not lossing low end torque/power. They have not designed nor tested this product on a 3.4l and therefore cannot garantee a performance increase versus a performance loss. the same with Cargraphic. It is interesting because both companies products include a different designed header for the 3/4l versus 3.6l unlike others which sell the same header for the 3.4, 3.6 996 and the 997. All interchangable. Anyone interested in putting headers on their cars should research and understand what they do and when, longer pipes versus shorter pipes, pipe diameter, etc., because all these factors influence your torque/power curve or loss of. IMHO....
The runner lengths are influenced by intake manifold runner length along with the lengths inside of the head. Those right there will determine what the length should be on each port. As for runner size. That all depends where you want your power to be and how to act.
Do you by chance know the firing order of the 3.4 engine? I'm going to be researching to develope a set of nice headers for my 3.4 over the winter.
geetee you should do a before and after dyno for those headers for the community
Firing order for the 3.4l and 3.6l are the same (1-6-2-4-3-5). Dont forget the Variocam Plus on the 3.6 though.. So, you are going to design and build your own headers? This should be interesting, please keep us posted....
These do not have the same amount of welds as many others i've seen. Look at cargraphics...each runner is 2 pieces welded together. Look at fabspeeds. There is a small section of middle pipe between the runners and flange. GMG, multiple ebay units, turbowerks, B&B, FVD, etc etc there are many many different headers on the market that are slightly different if you look closely.
I have only seen 1 independent dyno which was an ebay unit which lost hp. I have yet seen any of these "big tuner" headers dynoed by a 3rd party.
So, my very unscientific decision was to go with the zteks based as heavily on least amount of welds hoping least amount of areas that can break. Unfortunately, I have no place to dyno a before and after for these. I wish I had at least a performance box to run the same length of road and compare a before and after.
I just love building/creating things for my cars. I've been wanting to get a 911 for some time now to start developing parts for it. Mainly for cost savings. If it doesn't do any better than stock it atleast teaches me about the beast at hand. I know there's not much left to squeeze out of these engines (atleast it seems that way) but I want to give it a shot and see what I can produce.
Winters a coming so I will have plenty of locked in the cabin days
I spoke to AWE on the phone and do some interesting things with their designs and flow patterns. You may want to call them and ask some questions, etc., remembering that they have not developed headers for the 3.4l. Good luck and again keep us posted.
Well, I took the headers to a shop knowing I'd snap a few bolts. It turns out the OEM gaskets I purchased are larger than the gaskets that came with the car. My original gaskets matches the ztek headers flange perfectly well. I guess the new gaskets only come in 1 size possibly for the newer model?
Anyways....hard to tell if I've gained or lost any but definitely sounds better. Headers+200 cell+fisterD's.
Any suggestions on what to do next short of FI? Too many miles right now to go FI...
