The fuel system delivery is pulse width modulated (PWM), but essentially I run the pumps at full power at startup to build pressure quickly, then they go down to near-idle for normal drivability. The main benefit of this is to keep from heating the fuel, but there are other reasons why this is a good idea as well. Once you hit a certain torque target it ramps up the fuel pumps back to full speed. It basically has a low, medium, and high setting. I suppose if you were really determined you could do it in a returnless fashion and send just the right amount of fuel with the variability of the pumps but I haven't gotten that granular with it.

Yes, we are using the chiller - it is not compatible with the ESMotor intake manifold setup, but it has been modified to allow for more fuel flow and for fitment purposes. Since the chiller is actually on the return (vs the feed) there isn't as much concern with flow capability through the chiller.

 

Thank you for answering!
The Protomotive X-pipe is not 180 degree U-turn exhaust but more a left turbo to right tip exhaust right? With a connection in the centre for blendning the pulses? Good performance gain on that!
I have a muffled 2,5" X-pipe exhaust with bypass valves that goes to straight 3" (you can see the turbine wheel through the outer tips) and the difference in performance is quite evident. I have prepared with pre and post turbine pressure, but not had the energy to connect sensors to my S6+ yet. I will share the data when I have it, but from my memory from the dyno I hade the same back pressure as boost running 1.5 bar on my stock engine with my EFR 7163 turbos. The do88 inlet pipes do struggle a bit then in my opinion, so I totally agree that a intake upgrade is a must for an efficient package.
With my exhaust setup I solve the back pressure issue, but the sound is not so nice unfortunatley.

I will try to record some runs with the dragy app and see what the difference is on the same boost with closed vs open bypass valves.

Really nice stuff from Xona with the new approach on turbine design!

 

That's correct, the Proto is a left turbo to right tip and vice versa with a little overlap in the center. Much more free flowing than the traditional "Crash" X-pipe design, and it uses some off the shelf Magnaflow mufflers. It sounds good, and is quiet but doesn't have that same growl that the BBi exhaust does. I do miss that, but it's just not the right thing for my application. I'm really impressed with the new Xona UHF turbine, Garrett will likely never make anything like it - although I'm sure Precision Turbo will try to copy it pretty soon, like they did with the billet compressor wheels and other things that Forced Performance/Tial/Xona have introduced.

I'm actually working on my own performance box, along the lines of the dragy but a different design. I hope to post something about that sometime soon.

 

Here's a video recently put together from the November Wanna Go Fast race in Dallas. You can really hear me fighting traction in 1st/2nd/3rd gears. Has a little in-car footage. I need to finally get off my rear and make my own video from the footage, I have the entire run in-car.

​​​​​​​https://www.youtube.com/watch?v=IeiRsZkHM2U

 

nice! starring me with the sunroof open as a stunt double in the beginning

 

People were confusing our cars all weekend! They look very similar aside from that great looking XONA sticker on my car .

 

After a couple of false starts, namely getting Chris @ Unobtainium's time to do a new header design that places the turbo in a non-stock location, I have finally posted my headers for sale. Get yourself a set of Xona 6564S, 7164S, or be a big baller like ProdigyMB and try the 8264S with the internally gated housing and run my headers .

The for sale thread can be found here: https://www.6speedonline.com/forums/...997-turbo.html

 

rix,

Thank you for going out of your way and taking the time to let the members know what path you have gone in modifying your 997 Turbo. I have read every darn word you have typed in your posts. Thank you greatly on being very precise and letting us know of all the detailed modifications that you have done. You have an immaculately built car with some of the best car enthusiasts, mechanics & knowledgeable people whom have taken part into this build. Drive it & race it safely.

 

2nd that. New to Porsche. I've done plenty of other marque builds but this was a great educational break in to learn Porsche Turbos. Thank you!

I'm also seriously considering your Inconel headers in teh for sale section too.. Damn it, I really don't need another build right now...

 

Thanks, I try to be as specific as possible. When dealing with high end cars such as these everyone tries to do proprietary development and keep everyone else in the dark in order to create value for their brand. I try to respect that by not giving away all the secrets, but at the end of the day information gets lost if it isn't shared. It's a careful balance. I find it specifically awesome that you are in Kuwait, I actually lived there for ~2 years in the late 2000s. We should trade notes sometime, Kuwait holds a special place in my heart.

I have some photos of new parts, videos, and data that I've been procrastinating posting. The sad thing is I've had my car taken apart (for the constant pursuit of more power) so much lately that I actually went a little bit insane and bought a 991 GT3 to hold me over. The good news is that Mrs. Rix actually supported the decision, including calling me back after originally telling me I was nuts and suggesting that I buy yet another car to cover the gap caused by selling my CTS-V Wagon for the GT3. Who am I to argue? .

 

Best advice I can give to anyone on this thread is don't make your car so fast that you feel like you're going to die every time you press down on the throttle. I recommend the Xona 6564 and keep torque around 900 ft lbs. Unless you're trying to go (well) over 200mph in the 1/2 mile you don't need more. Even the 68mm VTG turbos are a little lazy. The 6564 is a great combination and drives just as well.

 

Getting ready for Texas2K19! I'll be competing in the roll race, Thursday and Friday of this coming week.

Have some new updates to share. The big one is that I've redone the intakes, headers, and turbos. I plan to go with some air/water intercoolers in the near future, and redoing the headers was necessary in order to position the turbos where we wanted them for that design. I think that was the single biggest thing holding me back previously. The new turbos are a rebuild of my "old" 6564S turbochargers into Xona 7164S turbochargers. They use the new turbine wheel from Xona/TiAL/FP. The difference from the old ones is that we stepped up the compressor wheel size from the 65lbs/min compressor to the 71lbs/min compressor. This is the same size found in the "3582" combination most are familiar with. The main trade off with using internal wastegates is that you don't have as much wastegate capacity, and a reduced range of operation. In order to combat this Xona has developed some new dual port wastegate actuators.


Dual port wastegate actuator. It has a port on either side of the diaphragm, which allows for finer control over boost vs. a single port.

Gregg at TiAL is just unstoppable. Everything he makes is beautiful.

A single port actuator applies boost to the wastegate spring, which opens the wastegate at the desired (spring) pressure. Pretty simple. If you have a 14psi spring in the wastegate, when you apply 14psi of pressure to the actuator it opens the wastegate and regulates the turbo shaft speed to 14psi.

When you add boost control, you either use some sort of bleeder valve to evacuate pressure from the line going to the wastegate (manual/mechanical boost control which is basically a very small boost leak), or an electronic controller with a stepper motor or pulse-width modulated valve to "hide" pressure from the wastegate in order to control it beyond its otherwise defined mechanical abilities. In this configuration you can run a minimum boost of spring pressure (14psi in our example) or you can use boost control to dampen/hide pressure from the wastegate and run more boost. Usually this type of arrangement is limited to somewhere around 2-2.5x the base spring pressure. 28psi should be possible with boost control, and 35psi is a bit of a stretch. That's what I previously was running in my car, and we went to a ~22psi spring in order to get boost up top to hold in the 35-37psi range.

This is where it gets interesting. If you have a dual port wastegate actuator, you can simply apply pressure to the opposite side of the diaphragm. So instead of using boost pressure from the intake manifold to open the wastegate, we can also use it to keep it closed. The main difference here is you can run a lower pressure base spring, and instead of being limited to 2 - 2.5x multiple for 28-35psi you can get more in the range of a 3.5 - 4x multiple in order to run 14-56psi of boost. This is useful in this type of car because in 1st and 2nd gear specifically, you need to keep the boost down (and ultimately) the torque output under control. It's no good if there is nothing you can do other than light the tires up in the first two gears. This was part of the problem I had at the last half mile race, aside from the surface being pretty slippery it was simply making too much boost in 1st and 2nd gear. This arrangement is also useful at higher RPM in upper gears where a single port wastegate would blow open, using the pressure from the intake manifold to hold it closed is what gives you the ability to run higher boost. This does complicate the boost control system a bit, but thankfully I'm running the Syvecs S6+ ECU which can just simply handle this without any limitations or trade offs.


Xona Turbo from the PRI show in December showing off the prototype dual port wastegate actuator. This didn't really make the "news", but is a big deal for internally gated setups. Also note the 3D printed wastegate actuator arm (right), we upgraded my turbos with the longer arm for more leverage on the wastegate as well.

The short version is that if you're using an internally gated turbocharger you need a dual port actuator if you want to run more than 30psi of boost and have a reasonable range of boost control. That, of course, is a statement targeted to the 911 engine, very large boosted V8 and V10 engines (Viper?) have different characteristics and don't generally run as much boost due to their larger displacement.

The next thing updated was the headers. Chris @ Unobtainium did a new design in order to accomodate my turbocharger placement specifications. This is more of a forward looking thing, I wanted to be able to use the biggest turbo inlet pipes I could find for the next Colorado Shift-Sector race, as well as be able to position things to make room for Air/Water intercoolers. I think somewhere along the way I finally gave in and declared my Turbo a garage queen.

Then this happened.


I went temporarily insane and purchased a 991 GT3.

I like big butts and I cannot lie.


The results of my first grocery shopping trip after the purchase.


After all this it looks like I'm going to have to have a pretty good year! LOL


The new turbos are XR7164S, 71lbs/min with the new Ultra High Flow Turbine. This is the real game changer that I've been posting about for a while, and lets you run a smaller turbine housing AND turbine wheel and get the same power output as much larger combinations. Since you're running smaller parts you get more response. It's like a free lunch in the turbo world. Here's some pictures from PRI that I took of the wheel. You'll see copies of it in the Precision Turbo booth later this year, I promise .


Ultra High Flow Turbine 3/4 view

Business end, this is where you can really see the difference.

While the old wheels work great, this new design has the same area at the turbine inlet to drive the turbine but removes a lot of material on the exit to really raise top end flow without much compromise. Whatever compromise may exist in the design is made up for the overall drop in the mass of the wheel. I ran these back to back with the standard 64mm turbine wheel and couldn't tell a difference seat of the pants in terms of response. If anything it actually hit harder. The best dyno number I've seen out of the car is ~1279whp on the 6564S. If one were to play some numbers games and extrapolate the possibilities you could argue that for 130lbs min of airflow (65lbs/min * 2 in a twin turbo configuration) the car made 1279 on the Dallas Performance Dynojet. That's approximately 9.83hp per pound of (rated) airflow. What happens when we go to a 7164S? If we say 71lbs/min * 2 = 142lbs/min, and multiply that by the same 9.83 we get 1396hp. Granted that's a ballpark figure but it would not surprise me at all if the car can make 1400 to the wheels, as we hadn't really even turned it up on the dyno yet on the old combination. Of course, there are some assumptions in there, the turbine can flow enough, the heads/cam/valvetrain combination are up to it, etc. It will be interesting to see. If there is time I will have it on the dyno this Wednesday to get some numbers before the race. These are probably best case numbers. Unless you have ported heads, cams, big valves, and ALL of the supporting modifications it's difficult to max out a turbo combination.


New Unobtainium Headers in process.

Getting there!

Chris really knows no bounds it seems...

Finishing up! X marks the spot for backpressure and EGT sensors .


Chris actually did the unthinkable as far as I'm concerned, he shipped the headers via DHL. As anyone who has read this thread remembers, DHL holds a special place in my heart. That place that you wall off and try to forget due to the amount of pain they've caused you. Of course, there was that one time that DHL sent Steve @ Driversource a nice gift basket and an apology letter for the last time their overnight service took 2 weeks. As luck would have it they *actually* delivered the headers overnight this time.


New headers test-fitted for install.


Other side


Close up of the dual port actuator, and new 3D printed intake pipes installed.


Here's the whole thing re-installed, with the air/air intercoolers, dual port wastegate actuators, and 3D printed intakes.

Another thing that we've been working on is integration between the Syvecs ECU and Motec dash. It sounds a little counter-intuitive, but the tachometer needle doesn't actually move fast enough to keep up with the engine until maybe 5th gear. So when it reads 6500rpm in 2nd gear it may be more like 7300rpm. This makes it a bit tricky to drive the car. I've taken more or less to driving it by ear, and and knowing what the engine sounds like. I don't generally drive it staring at the tach, but I definitely want some feedback that I can glance at from time to time that is accurate. Here's a video Wayne made while setting this up for me.

Steve put the whole thing together in ~2 days, ready for TX2K19!

It runs! It runs!

It's race week. I'm picking up my trailer, getting packed and ready to go. Hoping I really get some good video, vBox data, and pictures. Definitely going to do a dedicated 60-130 run to get the monkey off my back. Stay tuned...

 

Amazing!!!

 

One of the nicest big builds on the forum. Appreciate all the documentation I think this is the right balance of turbo for you. Good luck and can't wait to see it run

 

Wow those manifolds are beautiful, Cant wait to see how your car performs. Good luck at the event