This is a back to back (Monday dyno pulls, turbo swap Tuesday, Wednesday dyno pulls) comparison of the Xona Rotor XR6564 and the new 2019 Xona Rotor XR6564S turbocharger.


XR6564S vs. XR6564 at the same boost (or as close as you're going to get to being the same). Target was 330kpa, or about 33psi. Above that the regular XR6564 was running out of steam so it was difficult to get an apples to apples comparison, whereas the XR6564S still had lots left thanks to the improved turbine wheel.

Everyone gets excited about the compressor wheel, inducer/exducer diameter, flow rates, intertia, etc. No one is paying attention to the most important part of the turbocharger, the turbine wheel. No one except Xona Rotor. This is where the magic actually happens, as this is what converts the engine exhaust gas energy to drive the compressor wheel. Xona has quite literally re-invented the wheel. If I sound excited about it, it's because I am. I have been running turbo engines, and in general on a constant pursuit for more power for about 20 years. I've never seen this big of a jump in tech all at once.

We ran the XR6564 back to back vs. the XR6564S on my 911 Turbo -- the only difference being the new Ultra High Flow turbine wheel and found some jaw dropping results. I knew the first time I put my foot down at the WannaGoFast Dallas Half Mile that something interesting was 'afoot' after picking up 7mph over my previous best with more still on the table. After the race I put the car on the dyno to gather data in order to understand just how much of an advantage the new parts are.

The new turbine wheel immediately does two things for you.

1) It actually increases response.This is an entirely new generation of turbocharger, rewriting the rules of what's possible. You can now run a "small" turbine wheel in a "small" turbine housing and gain substantial performance at the same time. The rate that the boost comes on changed enough that we had to take some response OUT of it in order to keep the boost from overshooting our target of 33psi. I think this wouldn't be a problem if you had larger external gates, but I like the packaging of the Tial IWG housings.

2) While increasing response it also flows better in all out conditions. The way this new turbine wheel is made, it has 10 inducer tips, but only 5 exducer blades. So it gets great acceleration, but the outlet isn't blocked up with as many blades so the high speed and high boost performance is improved at the same time. My turbos are take full advantage of this because my .62 AR housings and this turbine wheel DROPPED my exhaust pressure by 100kpa at full power. - I wouldn't believe it if I hadn't watched Wayne calibrate and install the sensor with my own eyes. 14psi lower back pressure, and so much response that we have to take some of it out with the boost controller in the lower gears.

Here's a video of the car on the dyno:

Here's the car on the dyno at Dallas Performance in Dallas TX.

Practically speaking, what this means is that instead of ordering a 6564 or 7164 turbocharger in a .82 sized housing, now you can get away with running it in a .63 housing and gain a ton of response, in turn putting more area under the curve. It makes the car more fun to drive too. There are multiple sizes of this new turbine aero that will be released, I don't have all the specifications just yet - it will be announced at PRI the first week of December.

I believe I am going to be running the XR7164S next season - still working out the details. My car currently has the 2018 XR6564 turbo on it, we didn't bother swapping it back to the 6564S because the car will be going back to Driversource in Houston for header swap, exhaust changes, and bigger air intakes to feed the compressor wheels.

 

Rix
does your fuel delivery system pressure and return is linear with the power curve and demand ? is your controller controlled by the ECU ? and are you still using the chiller ? seems that that cooling part is the bottleneck in the system ?

 

Rix, any idea if the new turbine is to be used across the entire line? I have baby Xonas and to be honest I don't think the turbine is the limiting factor whatsoever (in my installation) so just more curiosity than anything else. I'll ask Tial directly - btw, their tech support is really great...I had some questions and minor functional tweaks needed and Mike at Tial was superhelpful and responsive to my emails.

 

Bogg yes there would be a gain as your bsfc would drop and your ve would increase from the reduction of exhaust gas in the cylinder I did estimates for my car running similar turbos to yours and the backpressure was not terrible however it could be better. This new turbine could possibly get the backpressure close to ideal below 22-24psi? I have to make some estimates and see.

The quicker spool is a function of the reduced weight from having splitters. From a turbine wheel design perspective weight is our biggest **** for spool up because it's inertia ^2. This is why the EFR get a lot of praise for quicker spool for example using their TiAluminide wheels.

For you guys that like whistle, this is Disney World. Using only half full blades will keep the frequency in human audible range a lot longer, Rix can confirm that I don't know what TiAL uses for their tongue to wheel ratio but that would be the other place to increase or decrease whistle with some turbospeed trade offs.

Would love to see one in person to really analyze it. From the picture yeah I can see advantages for aftermarket type problem statement but I see trade offs which is expected of course. Most of the trade offs I see are not a big deal in our case but would not fly in OEM use. There are some I would only know after I have one in my hands sorry I think it's a neat way to address our needs just don't know if all the trade offs are fine to make

 

Excellent info Maestro, as always. Not sure it is worth the trouble and cost for me to do this but something to consider anyway. I don't think I would want any more whistling than what I already have which is easily heard.

 

Honestly your turbos are so new that it's hard for me to justify it personally. Maybe when you build the engine one day or get tired of your current turbos? Some of the whistle could be taken care of by muffler design so don't get scared off by it Just wanted people to know that is one of the trade offs.

 

 

That's why I listed it as a trade off not a positive or negative. Some may love it others may not Just something to keep in mind Besides you need at least some turbo whistle to know you are alive right?

 

Is the whistle more pronounced OFF throttle or ON? On mine, the sound of ghosts following me (whoooooooo) is louder on deceleration. Not a deal breaker but I wonder how loud it is outside if I can hear it in the car, lol. I should have cruised the neighbourhood on Halloween.

 

You will hear this particular sound "turbine blade pass" more on decel. Because on throttle we pass thru our audible frequency faster and on decel the turbine slows down slower cause of inertia keeping it in this range more time. I wouldn't think of it as louder just more time in this range There are other factors that affect this but I would need a TiAL housing and this wheel in hand to comment lol

 

I don't want to turn this awesome thread into a NHV discussion cause that's boring But just know that so many things affect this. For example if you have bellows in your exhaust system like sometimes I have seen on aftermarket options for this car, we can turn that into a speaker. Yes I have run into that before.

 

Really nice data Rix!
Thanks for sharing!
Reducing back pressure with 100 kPa is brilliant for performance. So this was with the same compressor side?

What is your exhaust system currently? If I remember correctly you had some data from earlier dyno sessions with X-pipe and w/o, or were they never posted?

 

I can't hear a difference in the car, but standing outside of it at idle it sounds great. I wouldn't say there's a huge "energy" difference in terms of how much louder it is, more that you can hear the flutter/whistle along with the bass of the overall exhaust note. Sounds great. I don't know why the Maestro is so hung up on it .

 

My exhaust is currently a protomotive X-Pipe, with BBi exhaust tips ... Not exactly how I drew it up, but between waiting for parts and trying to make race schedules sometimes you just put it together and make it work.

Chris from Unobtainium is going to come down to Texas and do a new turbo kit for the car - he's already working on the headers, next step is a full titanium exhaust. The goal is to come up with a full headers/intake/exhaust package, which doesn't really exist in the 997 aftermarket for 1000whp+ power cars. The part I'm not sure about is whether I'm going to have the Y-Pipe re-done as well, and do a stock style airbox with a less wild Y-Pipe design. I will be working out those details in the next 30-60 days.

There is some data between the BBi XPipe (one of the best sounding exausts on any car, period) and the current Protomotive but my eMap sensor decided to die in the middle of it and I don't have real quantifiable data. I can tell you the car was .3 seconds quicker 100-150 on the Protomotive, and that it made more overall power but the dataset quality didn't meet my criteria to post. There isn't an "off the shelf" exhaust I'd recommend for a ~1200-1500whp car right now, hopefully we can change that.

 

Yes, I believe there are 4 new UHFTurbine wheels coming from Xona Rotor. All the details will be out the first week of December. They range from small to large, there is something for all power levels in there.