Ported Headers. What positives?
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cjv, this is not gasket matching. What we are talking about is grinding away the excess weld material in the stock headers (there is a lot of it!). There are threads here and on Rennlist started by Kevin (UMW) describing the whole process.
Porting the inlets of the flange itself (gasket matching) would take a remarkable amount of work and many bits as it is very hard stainless steel. But since you mentioned it, I was surprised to see how much smaller the flange inlets are compared to the size of the gasket. If it was intentional for the reason you stated then it makes sense. Do you have any data to support that info? I only ask because match porting is a common practice in racing.
Porting the inlets of the flange itself (gasket matching) would take a remarkable amount of work and many bits as it is very hard stainless steel. But since you mentioned it, I was surprised to see how much smaller the flange inlets are compared to the size of the gasket. If it was intentional for the reason you stated then it makes sense. Do you have any data to support that info? I only ask because match porting is a common practice in racing.
In English, their is a slight step where the top of the head meets the top of the exhaust. You do not want to smooth out this step. What occurs, without this step is the sound harmonics in the exhaust travel back through your valve train resulting in a loss of some power.
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It is well documented in some books. Now I will have to go back and get this information for you.
In English, their is a slight step where the top of the head meets the top of the exhaust. You do not want to smooth out this step. What occurs, without this step is the sound harmonics in the exhaust travel back through your valve train resulting in a loss of some power.
In English, their is a slight step where the top of the head meets the top of the exhaust. You do not want to smooth out this step. What occurs, without this step is the sound harmonics in the exhaust travel back through your valve train resulting in a loss of some power.
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BTW, OEM headers are all the same. There was no difference between k16 or k24 headers.
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Chad, I bought this book back is 2003, I think, after asking you the name. It's a very good reference guide.
Mike
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Wow, are you 110% sure about that?!?! I was always under the impression that they were different between the k16 and k24 cars. I just learned something, but can you confirm for sure? Thanks for the info!
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Headers are the same for a K16 or K24... ditto! As far as porting... I didn't want to go crazy. I think Porsche has spent good money on R & D... so I just cleaned up the lower flanges where the factory header bolts to the turbo. There was a lot of excess weld in that flange so I spent some time cleaning/opening it up. I probably opened it up another 15% to 20%. I figure that has to help feed/spool up the turbos. As far as noticing a difference...???
