X51 Headers revisited
05-15-2007 | 11:45 PM
#46
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From: Austin
Originally Posted by 4thporsche
Since no one else has responded I'll give you my best guess..... since the Fabspeed and AWE exhaust systems fit on both the 997 and 997S I would say that the x51 header will fit the base 997. Take 5 minutes and call a dealer (SunCoast?) and they can tell you for sure.
07-06-2007 | 06:00 PM
#47
Pro
Joined: Mar 2002
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Not entirely off topic, but which set of O2 sensors provide usable information to the ECU. I have been told one set just tells the ECU that the cat is working and the other set what the mixture is. I am thinking it is the first set that is important (ones befor the cat). If that is correct is there a way to trick the ECU so it thinks the CAT is there and working so I dont get CELs.
07-06-2007 | 06:55 PM
#48
Burning Brakes
Joined: Dec 2006
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Originally Posted by Turboflyer
Not entirely off topic, but which set of O2 sensors provide usable information to the ECU. I have been told one set just tells the ECU that the cat is working and the other set what the mixture is. I am thinking it is the first set that is important (ones befor the cat). If that is correct is there a way to trick the ECU so it thinks the CAT is there and working so I dont get CELs.
What was nice about bimmers, is the fact there is software for the M3's that delete the rear 02 code from the DME (ECU)so the DME just ignores the rear 02 signal. I had this on my M3 as I was running 100cpi metallic race cats and got a SES light on my M3. The race "shark" software from Turner Motorsports solved this.
Dave
07-06-2007 | 08:04 PM
#49
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Originally Posted by cobra06
When I had the stock and X51 headers next to each other I couldn't help saying to myself "what were they thinking", I've seen better exhaust manifolds on 1953 Ford Tractors. The stock pipes neck down right at the flange, and I would guess there is a turbulent flow with the quick restriction to a narrow diameter, the X51's stay open from the flange with the same diameter tube.
installation was extremely easy. Took it for a drive. A little more deeper tone, and purely subjective...seemed more responsive to the throttle, reached up through the RPMs a bit quicker. Maybe just psychological, but at least I don't have to look at that stock set with the bad weld job. Overall, to me it was a very worthwhile relatively inexpensive modification, using an OEM part
installation was extremely easy. Took it for a drive. A little more deeper tone, and purely subjective...seemed more responsive to the throttle, reached up through the RPMs a bit quicker. Maybe just psychological, but at least I don't have to look at that stock set with the bad weld job. Overall, to me it was a very worthwhile relatively inexpensive modification, using an OEM part
07-06-2007 | 08:30 PM
#50
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From: Santa Barbara, CA
Originally Posted by cobra06
I just received a set of X51 Headers from Sunset, `$550.00 with new bolts and gaskets. Welds were a bit rough on the intake, so I ground the proud bead down with a flap wheel, and smoothed the entire port. They are a vast improvement over the 997S stock pipes, as far as appearance and design. The diameter is about. 7.0mm larger then the stock, which varied between 41-42mm (stock) depending on which collector you measured. Even if it doesn't bump HP significantly, they look better and without a doubt flow better, and that makes me feel better. Can't see how they can hurt.
Please list the part numbers if you would be so kind. I'm thinking of going in this direction the end of the month. (And price breakdown if you have that detail).
07-11-2007 | 10:50 PM
#52
Instructor
Joined: Jul 2007
Posts: 138
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From: Seattle
Great info, thanks! Im going to look into this as well. Not sure if I'll be able to do my own mechanical work anymore though.. we'll see 
Originally Posted by cobra06
When I had the stock and X51 headers next to each other I couldn't help saying to myself "what were they thinking", I've seen better exhaust manifolds on 1953 Ford Tractors. The stock pipes neck down right at the flange, and I would guess there is a turbulent flow with the quick restriction to a narrow diameter, the X51's stay open from the flange with the same diameter tube.
installation was extremely easy. Took it for a drive. A little more deeper tone, and purely subjective...seemed more responsive to the throttle, reached up through the RPMs a bit quicker. Maybe just psychological, but at least I don't have to look at that stock set with the bad weld job. Overall, to me it was a very worthwhile relatively inexpensive modification, using an OEM part
installation was extremely easy. Took it for a drive. A little more deeper tone, and purely subjective...seemed more responsive to the throttle, reached up through the RPMs a bit quicker. Maybe just psychological, but at least I don't have to look at that stock set with the bad weld job. Overall, to me it was a very worthwhile relatively inexpensive modification, using an OEM part
07-12-2007 | 02:22 AM
#53
Burning Brakes
Joined: Feb 2006
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From: Chicago area, IL USA
The more I look at the stock 3.8L headers, the more I think that Porsche is holding out on us...
100hp/liter is totally possible in a NA motor. The X51 3.8 hits the mark. Why does it cost $20k extra?
(If I can solve this problem, I can fix world hunger & global warming, too...)
100hp/liter is totally possible in a NA motor. The X51 3.8 hits the mark. Why does it cost $20k extra?
(If I can solve this problem, I can fix world hunger & global warming, too...)
07-12-2007 | 10:41 AM
#54
Race Director
Joined: Mar 2006
Posts: 15,358
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From: Tampa
Originally Posted by dstrimbu
The more I look at the stock 3.8L headers, the more I think that Porsche is holding out on us...
100hp/liter is totally possible in a NA motor. The X51 3.8 hits the mark. Why does it cost $20k extra?
(If I can solve this problem, I can fix world hunger & global warming, too...)
100hp/liter is totally possible in a NA motor. The X51 3.8 hits the mark. Why does it cost $20k extra?
(If I can solve this problem, I can fix world hunger & global warming, too...)
07-12-2007 | 11:22 AM
#55
Three Wheelin'
Joined: Dec 2005
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From: Houston, TEXAS!
I honestly don't know $heet about whether or not this will provide a performance gain, but there is no arguing those stock headers look like a total POS, and the upgraded model looks awesome. I cannot fathom that this would not help in some manner on the performance side. I am so going to do this upgrade.
07-12-2007 | 11:29 AM
#56
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From: Santa Barbara, CA
I have a set on order with Sunset Porsche in Portland. Will be putting them on mine in a few weeks after some port cleanup. With bolts and gaskets out the door it was something like $565.
07-12-2007 | 01:01 PM
#57
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From: Tampa
It really suprises me that out of all the Porsche magazines worldwide not one of them has done any type of muffler or header shoot out. They do no performance type of articles or shoot outs period showing dyno results and 0-60 and 1/4 mile times. How about a shock and/or spring shoot out with track times? The Vette mags and many other car mags do these type of deals all the time.
I'd like to see how the X-51 header stands up to the longer length tube headers that should scavenge exhaust better thus making more power like the Fabspeed and AWE headers.
I'd like to see how the X-51 header stands up to the longer length tube headers that should scavenge exhaust better thus making more power like the Fabspeed and AWE headers.
07-12-2007 | 02:40 PM
#58
Burning Brakes
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Originally Posted by mdrums
It really suprises me that out of all the Porsche magazines worldwide not one of them has done any type of muffler or header shoot out. They do no performance type of articles or shoot outs period showing dyno results and 0-60 and 1/4 mile times. How about a shock and/or spring shoot out with track times? The Vette mags and many other car mags do these type of deals all the time.
I'd like to see how the X-51 header stands up to the longer length tube headers that should scavenge exhaust better thus making more power like the Fabspeed and AWE headers.
I'd like to see how the X-51 header stands up to the longer length tube headers that should scavenge exhaust better thus making more power like the Fabspeed and AWE headers.
I agree I wish one of the PCar mags would do something like this like Muscle Mustangs and Fast Fords and such. It would be nice. My experience with equal length vs. non equal length is that the equal length can make more midrange power (by a few hp at our hp level) but nothing really on the top end.
Dave
07-12-2007 | 02:42 PM
#59
Burning Brakes
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Originally Posted by Edgy01
I have a set on order with Sunset Porsche in Portland. Will be putting them on mine in a few weeks after some port cleanup. With bolts and gaskets out the door it was something like $565.
Don't take to much off of the header port, as it can compromise the weld. Mine were pretty clean from the factory, and it looks as if the factory cleaned them up quite a bit themselves. I did go over them very lightly with a dremel tool just to take a few humps down a tad more.
Dave
07-12-2007 | 05:01 PM
#60
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From: Santa Barbara, CA
Originally Posted by Dave07997S
Don't take to much off of the header port, as it can compromise the weld. Mine were pretty clean from the factory, and it looks as if the factory cleaned them up quite a bit themselves. I did go over them very lightly with a dremel tool just to take a few humps down a tad more.
Dave
Dave
Thanks for the tips!