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So I have been reading a little about a small mod that I considered undertaking: porting and polishing the stock 997.1 headers. I have read about some mild performance gains (faster spool of turbos) but mostly was interested in attempting this to see if I could do it, and it also allowed me a project that I could undertake in the man-cave at my leisure.
I didn’t want my car to be undriveable while I tackled this, so I bought a stock set of lightly used 997TT headers from a friendly RL’er for a fair price.
I used an air powered die grinder and a carbide cutting bit to do the bulk of the work.. I only have a 15Gal compressor, which will work with the die grinder, but it runs out of steam unless you stop every 5-10 seconds. Thankfully my neighbor has a 60 Gal compressor with a 50ft hose, so I borrowed his air so I could have a nice continuous operation of the grinder.
Looking at the stock headers, there’s a fair amount of extra metal around the welds.. I wanted to keep the lip/ridge around the collector but smooth out the bigger humps.
I started with the carbide bit, followed by some 80 grit cloth rolls, followed by 130 grit, followed by some emery paper. The surfaces of the exhaust runners and collector are now super smooth..
I cleaned them up by washing them with my power washer.
I used all new gaskets and the install took about 2 hours.. not bad.
Unfortunately most of my pics of the fully polished product got corrupted by my phone, but I have some of the porting..
I considered performing the same operation on mine. I know a lot of the 996 guys do this with success but, Do you think to much reduction could cause a cracked weld?
They're the same part as the 996TT, but yes I would think if you removed too much or flatened it out to much it could end up cracking.. Its hard to see in the pics but I smoothed out the uneven spots and left a small ridge where the welds were.. Hopefully it holds up!
Nice work, but porting and polishing may have the opposite effect you were looking for unless you know exactly what you want the engine to do. E.g., do you want low end torque, high-end power, mid-range torque etc. Based on that the flow is calculated, etc.
The stock intake, head and headers on the 911 turbo are definitely good to !,000 hp - as SRM Engineering just attested to also.
On a Naturally Aspirated engine, it's a whole different ball of wax - spending $400 on porting and polishing the heads on a 2008 Z06 I gained 50 hp and 60 lb-ft of torque!
Fabworx does great work...and that's why I'm installing that type of header on my car as we speak...but I'm going to have to disagree on 997 headers being good ..for 1000 hp....I'm not saying it can't be done but there was a noticeable diffrence on a turbo that I was very familiar with when he upgraded his turbos..that being when his stock headers were changed I noticed faster spool and a nice power surge at 3.5 rpms...if you have light mods its not needed but as your reaching goals past 600awhp that turbo is sucking more air...
Curious to find out how much you found those headers for. I have my set that is simply sitting there looking pretty (well, ugly as they are not really pretty) doing nothing.
These headers are one of the nicest I've seen and I'll be posting a thread with a dyno and some other bolt ons to see how these bad boys spool up...I'm not sure on price but I'm sure they'll work something out with you..
Curious to find out how much you found those headers for. I have my set that is simply sitting there looking pretty (well, ugly as they are not really pretty) doing nothing.
I ported mine years ago. My welds were huge and it probably increased the port area 15% or so. No need to go crazy. You don't want to grind through the weld. You also don't want to polish the port. Ideally you want the surface lightly textured to energize the boundary layer air and improve flow. My turbo builder is a big fan of porting the stockers and says on back to back set ups he's reduced spool by 300 rpm. Reality or wishful thinking? I have no idea but for a couple of hours of work it's worth it I'm my opinion. Some of the headers are really bad, some pretty decent. Only one way to find out and if you already have them off the car, that 80% of the battle.
