DR911s

I just completed installation of new Flat 6 diverter valves, following the very helpful videos of Tier1Terrier and Mingus Dew and Flat 6 Motorsports. And I did some boost air leak down testing following the excellent video of Mingus Dew. Unfortunately for me, I didn't have available the necessary bits of hose and and bolts and clamps to make plugs for the two differently sized nipples that come off the right side [passenger side] of the Y-pipe just before the Y-pipe connects to the rubber boot whose other end connects to the throttle body, or to separately test the approximately 1" ID hoses that connect to each branch of the Y-pipe to enable testing of the symposer system components for leaks, so I consider my leak test inconclusive. My car certainly did not hold boost pressure like Mingus Dew demonstrated with his earlier generation true Turbo car. The plumbing for 991.2 3L twin turbo engine cars is different in many areas than in an earlier generation true Turbo car!

I did not find any loose or missing connections for any of the maze of vacuum/pressure signal hoses and clear plastic [?Nylon?] tubes that are visible when the rear bumper cover is removed. And the "master" vacuum/pressure signal hose that connects to the Y-pipe and when properly installed goes over the top of the right [passenger] side branch of the Y-pipe to the large solenoid valve that is mounted via a tab/slot on the top center of the air box cover was perfectly routed. Close examination of it revealed no damage to it or its coupling or internal O-ring where it attaches to the Y-pipe nipple. That hose is actually a piece of plastic [?Nylon?] tubing that is covered with a braided protective jacket.

I chose to use the little molded plastic right angle vacuum signal hose connectors supplied with the Flat 6 diverter valves that I installed; they very securely grip the metal nipple of the vacuum hose line to the diverter valves. Those right angle fittings can be released if necessary using a pick tool to lift the grip ring at the bottom of the fitting pulling away from the valve. I reused all of the OEM hose clamps, and made certain that all hoses were fully seated and properly oriented and likewise for the clamps. [The OEM diverter valves appeared to be properly installed and properly functioning when removed... and sealing well; I couldn't blow any air through them. I realize that my lung pressure is far less than boost pressure.]

While my car with slightly lifted at the rear, I also checked the functioning of the waste gate actuators and linkage, and did not find any corrosion or other issues with smooth movement throughout their full stroke range. I also checked the functioning of the actuators for the OEM Sport Exhaust, and they, too, did not have any corrosion and functioned smoothly throughout their full stroke range.

At minimum, I learned a lot about my car and how Porsche puts components together... and will be ready to do the next engine air filter change myself! The electrical connectors were to me the most daunting part of this project, because they are of several different designs and require different amounts of force applied to the right component as you pull or lever them apart. But careful study before applying force worked every time, including for the somewhat tricky double wiring connector holder buried behind the right tail light assembly. The secret to it is that there is a latch at the bottom of the holder which when released allows the cover to swing up and out of the way to access the actual wiring harnesses connectors which are easy to separate after removing them from the holder. [Thanks to whomever posted that little but important detail!]

Next step is to do a little test driving! I am currently running the FVD Brombacher tune file, since the error codes occurred regardless of whether the OEM or FVD tune was installed.

Side question: Has anyone who has a 2017 or newer Carrera with the 3L twin turbo [?9A2?] engine noticed motor oil in the filtered air inlet and boosted air outlet of the right [passenger] side turbocharger? I've noticed a bit of oil there and throughout the Y-pipe and the rubber connector hose to the throttle body. For that reason I also cleaned the ?pressure? sensor that is mounted on top of the Y-pipe just upstream of the throttle body boot. Flat 6 and others sell a vortex type collector and catch can that can be mounted to the right side turbocharger. I'm thinking that such motor oil vapors will be contributing to buildup of carbon deposits on the back sides of the intake valves which is not good for long term performance. If it matters, I'm running Mobil 1, 0W-40 European Formula motor oil, the same as the dealership has used for all maintenance services from the beginning for my car which now has about 35k miles, including about a dozen track days. I rarely exceed 7k engine rpm, usually short shifting the PDK in manual mode when on track at between 6k and 6500 rpm, and hardly ever use Sport Plus mode. The engine doesn't appear to use much oil, even when tracking the car. Less than 1/2 quart total between oil changes which are at about 5k miles intervals.

VektorPerformance

Yes! That is exactly why we designed our Air Oil Separator. You can find a customer review in this thread.
https://rennlist.com/forums/991/1348...mance-aos.html

Boost leaks are always a challenge. Good work on diving into the car which scares off most owners.

DR911s

Thank you, Vektor.

For Tier1Terrier et al.:

Yesterday evening [Sept. 9] after completing the Flat 6 diverter valves installation on my 2017 C2S that has Sport Package and PDK, and checking and rechecking all hoses connections and clamps and the turbo wastegate actuators and linkages and swivel joints at the wastegate lever arms, I took a short test drive. I was within my city limits so full throttle and high rpm in any gear weren't possible, but my drive included a lengthy hill and during that ascent with only about half throttle I observed 17 psig on the MFD! I was driving in Sport Mode with the FVD tune. Ambient T of 73F. I don't recall ever seeing that before, in any driving mode with either the OEM tune or the FVD tune. More driving/testing is needed, but I'm hopeful that I have achieved some improvement. Only a lengthy drive will tell me if the stuttering recurs or any fault codes.

Today I did another ~20 miles within city drive that confirmed that all electronics systems appear to be working normally, including the blind spot warning system and rear camera.

I hope to make a longer rural trip later this week where I can do a little testing of various drive modes and WOT into upper RPM range. I have not erased the earlier set Fault Codes P0299 and P2262, figuring they will be helpful to the dealership if I have to resort to them for resolution of the issues with my car.

MingusDew

Those videos with the 997.1 Turbo aren’t mine, just some helpful ones I came across and saved for reference as the layout and approach to service is very similar.

For the electrical connectors, many are designed to be under tension when clipped together, to prevent water intrusion, and pushing them together releases tension. So sometimes, unintuitive, but you need to push the connector together to release tension on the latch, then they’ll pop apart.

DR911s

Thanks! That tip regarding the electrical connectors is an excellent point!

So, the preferred sequence is to
1) push together the two pieces of the electrical connector, and
2) while pushing them together, squeeze the lever arms (or use a tool such as a small screwdriver) to depress them and thereby release the lobe of the lock from its corresponding notch or detent, and while doing so,
3) pull or push apart the two pieces of the connector.

Of the connectors I encountered when doing installation of new diverter valves on my 2017 C2S, that for the rear spoiler was the most difficult to disconnect, due to its size. The easiest ones I've encountered when working on my car were those for the ABS signal lines at the wheel hubs; they literally popped when I used a small screwdriver to work their lever arms, and they have a handy recess molded into the lever arm just for such a tool.

Regarding the video, thanks, again to you for posting it, and to whomever made the original video. As you said, it's a very useful reference.

DR911s

For Tier1Terrier et al.:

My Fault Code P0299 "Boost pressure deviation" and Fault Code P2262 "Boost pressure less than set point value" appear to be solved via installation of the Flat 6 Motorsports diverter valves on my 2017 C2S which has Sport Package which includes Sport Exhaust and Sport Chrono, and PDK and RWS!

Today I did a road trip of a little over 100 miles in two legs of about 50 miles each on rural roads, and tried all driving modes and the Sport Response button, and all appear to be working very well. I'm running the FVD Brombacher DME [ECU] tune, and the Porsche OEM PDK software. I do not know if FVD's engine tune changes anything in the PDK programming, but we know that Porsche uses torque limits as control values, too. Fuel used was Meijer 93 octane, which is allegedly Top Tier rated; there was no ethanol label on the pump.

As John of Flat 6 has stated much earlier, 991.2 Carrera cars equipped with his EVOMS diverter valves [https://flat6motorsports.com/collect...991-2-carrera] will exhibit crisper upshifting response. I can confirm that behavior, and for the first time for me in my car, when in Sport Mode or Sport Plus Mode, and applying about half throttle, the car not only responds very quickly but also will upshift earlier and very crisply, Previously, it would hold the lower gears longer and allow the engine RPM to go quite high before upshifting, and often when I manually upshifted it, the car's algorithm would soon thereafter drop it down a gear or two. I did not observe any of that today. Sport Plus of course, being more abrupt and sending a greater impulse of torque as the PDK upshifts.

Previously to the changeout of the OEM [Audi labeled!] diverter valves on my car, the maximum boost I saw on the MFD was 12 psig almost every time, and rarely 13 psig and extremely rarely 14 psig. Now I can easily reach 17 psig in any operating mode, and that doesn't require high rpms or even half throttle. That 17 psig on the MFD is reached rather quickly, and my guess is that the actual boost value is higher at times, but is not being displayed due to the preset maximum value enabled by Porsche to be displayed.

No stuttering or hiccuping was observed. I'm still holding back on stating that issue has been solved because when it occurred in the past, the car had been driven for a longer time and mileage before the anomaly occurred, but I'm very hopeful now. To me, it's almost like driving a new, more powerful and more responsive car.

I'm looking forward to a track day, or a long drive in mountainous roads, to confirm that all of my issues have been resolved.

Revsportz

For anyone using the turbosmart kompact plum back diverter valves part number TS-0203-122, is the supplied green spring enough for 991.2 3.0 with APR GTS tune? Or did you guys had change springs?

thanks,