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I had mine installed this past Sunday afternoon/evening - just getting around to posting now. I'll share my impressions on the build quality, installation process, and feel of the car post installation. The high-level summary is that I'm very happy about these headers and want to congratulate the Dundon team on a great product. I did quite a bit of reading and research on other solutions out there and went with Dundon due to their open and transparent engineering process, attention to detail, and reputation in the Porsche aftermarket performance world. Oh, and they also have the highest gains out there so far .
Build Quality & Installation
Installation took a very experienced mechanic about 4 hours to complete. Aside from me handing him an occasional tool and holding things in place while he bolted them on, it was a one-man job. His comments upon inspecting the headers pre-installation were that the workmanship was on-par with some of the the best products he's ever worked with. The documentation was good - especially the revised version with pictures that Dundon sent over after they had shipped the headers. The welds are excellent, the materials used are high-end (even down to the freely spinning springs), and the attention to detail is top-notch. My mechanic has been around high-end and bespoke racing products for 15+ years (often fabricating small custom bits himself to get the job done) and said that he was thoroughly impressed with the headers. Installation went smoothly on the left (driver's) side - everything just slipped right into place and bolting back on was straightforward. The right (passenger) side was a bit more difficult to get everything to mate up cleanly. We had to loosen the exhaust midpoint mount to get things to move around a bit to align with the exit point on the headers, but overall not a big deal and everything tightened up nicely with nothing seeming to be out-of-place in the end. The car was started (wow), warmed up, and checked for leaks around all gaskets and pipe joins - everything was airtight and good to go.
Post Install Feel
When the exhaust flaps are CLOSED, the car can easily be driven in a way that continues to maintain factory noise levels (same thing Alan C. mentioned earlier). However, with exhaust flaps OPEN or when you really stand on the throttle with exhaust flaps CLOSED, the car is significantly louder both inside and outside and the sound is nothing short of glorious (IMO). There also seems to be noticeably more "crackle" when letting off the gas after a hard pull, but this may be biased feedback due to me paying more attention right after I've had work done.
I'm currently running the stock tune. The power curve is noticeably smoother, and the seat-of-the-pants dyno can definitely feel the additional pull and power. I didn't dyno the car pre-install, but did a number of 2nd, 3rd, and 4th pulls at WOT on my way to the shop so I could have something in recent memory to compare to after the install was complete. The power is there and its real - the car feels (and sounds) significantly meaner than before. As previously noted, it gets really fun up around 3500+ RPMs and pulls hard all the way to top. I plan to get the car on a dyno, but that will be sometime during the 2017 driving season after a few more changes that I'm considering. Can't wait to get this out to the track - corner exits and straights should be noticeably different with the upgrade.
Here are a few pics with some descriptions:
Dundon Race Headers (top) vs. stock headers (bottom) - note the difference in length and diameter as well as the much-discussed 4th pipe
Headers off the car, gasket prepped to receive new part
Close up shot of installed header
Dundon Race Headers installed - super clean!
Here's a video of the initial cold start just after installation was complete. Great first impression Dundon!
Also, if anyone in the Austin, TX area wants to get together to experience these headers, please feel free to shoot me a PM and we can arrange something (possibly a few laps at Harris Hill?). Always good to meet other enthusiasts out there.
Great work guys! I think you're on to something here...can't wait to see the catted version for comparison.
The photo of the exhaust ports reminded me of one other item. When I looked at mine, 7700 miles, there was no carbon buildup on the exhaust valves. The perimeter of the valves had a light brown color
Great post - Thx 512GT4. Is the sound clip with the valves closed?
Thanks! Yes, I should have been more specific in the original post. The cold start was valves closed.
Originally Posted by ajag
Nice post 512GT4, can't wait to experience mine!
I think you're going to like them...
Originally Posted by KareemGT4
so no CELs guys?
Nope, nothing yet. My mechanic said he'd seen similar strategies that had worked elsewhere in the race world (Pikes Peak Hill Climb racers) to avoid codes without a bunch of reprogramming or hacking up the car too much. Nice and simple - always the best as long as it works. This isn't a daily driver for me, so others might have better feedback - definitely something to track over time.
Thanks! Yes, I should have been more specific in the original post. The cold start was valves closed.
On cold start the valves are always open,regardless whether you have pressed the exhaust button or not,for about 30 seconds or until you touch the throttle.
On cold start the valves are always open,regardless whether you have pressed the exhaust button or not,for about 30 seconds or until you touch the throttle.
Didn't know that - thanks...apparently they were open
12-13-2016, 01:38 PM
I'll get vids of both pre and post runs.
Got mine installed!
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