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?

 

How well do they match the opening in the heads? If they match not much to do. If smaller match them.

 

Go for aftermarket gaskets??? Example fabspeed.

 

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.

 

Why do those look like Ebay headers??

 

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.

 

 

Headers look pretty decent, what pipe size is that?

 

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....