X51 Headers redux...
Nordschleife Master
Joined: Jul 2009
Posts: 5,963
Likes: 113
From: Vancouver, BC
It's no secret the 997s ability to breathe can be enhanced. The stock header design, IMO, is awful. The X51 units open the car up a bit in the mid range and offers a throatier tone especially when combined with PSE. I wouldn't expect much of a hp increase though. Swap out your cats with 200cell offerings if this is your goal.....
If you're into DIY projects, this one is quite simple and can be done in an hour or two. Be careful of the disconnect at the cats---at least on my '05 the 3 point flange had studs and a few snapped when too much torque was applied to loosen the nuts.
The following pics courtesy of Edgy01 ( Dan ) illustrates the different designs.
Relatively inexpensive around $700 compared to aftermarket pieces. Most here will tell you this mod is a go !
If you're into DIY projects, this one is quite simple and can be done in an hour or two. Be careful of the disconnect at the cats---at least on my '05 the 3 point flange had studs and a few snapped when too much torque was applied to loosen the nuts.
The following pics courtesy of Edgy01 ( Dan ) illustrates the different designs.
Relatively inexpensive around $700 compared to aftermarket pieces. Most here will tell you this mod is a go !
Former Vendor
Joined: Oct 2009
Posts: 1,691
Likes: 2
The full AWE system also got around the same amount of increases in torque. I can clearly see that the benefits are much greater on the C2S than the C2.
+11-12 crank hp, +10-11 crank tq for 997 - tied in with an engine chip of 10+/10+
That is a nice bump in torque.
+11-12 crank hp, +10-11 crank tq for 997 - tied in with an engine chip of 10+/10+
That is a nice bump in torque.
Rennlist Member
Joined: Jun 2001
Posts: 1,916
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From: The NC
Did you ever get an answer as to whether an X51 header on a 997.1 C2 (non S) is worth it? I do understand that on an S (997.1) it's worthwhile.
Rennlist Member
Joined: Jul 2009
Posts: 6,087
Likes: 51
From: MA
No. Look down your C2 car and you`ll see that stock headers on C2 car are almost exactly same as those 'X51' headers for C2S, just off slightly less diameter. C2 is OK with headers, just needs 200 cell cats.
Poseur
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Rennlist Member
Joined: Nov 2005
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From: Santa Barbara, CA
Not necessary. Although I ported and polished mine before I put them on. They looked much worse than the 3.8 OEM headers inside until I cleaned them up.
Nordschleife Master
Joined: Jul 2009
Posts: 5,963
Likes: 113
From: Vancouver, BC
Now, on that note... is there ANY advantage to update the software to X51 Software if you only did X51 headers and PSE? IF, any dealer would do it to begin with!
Nordschleife Master
Joined: Jul 2009
Posts: 5,963
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From: Vancouver, BC
Rennlist Member
Joined: Jul 2009
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From: MA
aftermarket ECU flash pushes your car maps beyond limits of stock emissions restrictions and that is where you actually gain additional power, there are no real miracles there. ECU flash also may increase your rev limiter to 7500 from 7300 rpm. custom maps can be pre-tuned to 93 octane gas to give additional gain and also you can activate 'sport' throttle response map permanently (if you car does not have 'sport' button - it helps to resolve this issue).
Nordschleife Master
Joined: Jul 2009
Posts: 5,963
Likes: 113
From: Vancouver, BC
he says no 'need'. that means stock ECU will work just fine.
aftermarket ECU flash pushes your car maps beyond limits of stock emissions restrictions and that is where you actually gain additional power, there are no real miracles there. ECU flash also may increase your rev limiter to 7500 from 7300 rpm. custom maps can be pre-tuned to 93 octane gas to give additional gain and also you can activate 'sport' throttle response map permanently (if you car does not have 'sport' button - it helps to resolve this issue).
aftermarket ECU flash pushes your car maps beyond limits of stock emissions restrictions and that is where you actually gain additional power, there are no real miracles there. ECU flash also may increase your rev limiter to 7500 from 7300 rpm. custom maps can be pre-tuned to 93 octane gas to give additional gain and also you can activate 'sport' throttle response map permanently (if you car does not have 'sport' button - it helps to resolve this issue).
Poseur
Rennlist Member
Rennlist Member
Joined: Nov 2005
Posts: 17,730
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From: Santa Barbara, CA
The X51 kit has different software because the heads are entirely different. Stronger valve springs even provide a higher redline. I have been running my 06 S for a couple of years with the X51 headers and the PSE and never bothered with any software. it's not applicable.
Last edited by Edgy01; Oct 16, 2012 at 12:58 AM.
Nordschleife Master
Joined: Jul 2009
Posts: 5,963
Likes: 113
From: Vancouver, BC
The X51 kit has different software because the heads are entirely different. Strongly valve springs even provide a higher redline. I have been running my 06 S for a couple of years with the X51 headers and the PSE and never bothered with any software. it's not applicable.
Rennlist Member
Joined: Jul 2009
Posts: 6,087
Likes: 51
From: MA
