Introducing the SteamSpeed STX 71 for Mitsubishi Evo X
You’ve asked, we listened. SteamSpeed now supplies turbos for the Evo X. To start with, we brought over our same proven 59 lbs/min STX 71 CHRA we have used since the beginning on the STI. On the STI, it typically puts down 400-450 whp and ft*lbs on pump gas. How do you recon it would perform on a Evo X? We set out to find out. More pictures here…..
SteamSpeed STX 71 for Evo X Specs
Make no mistake, the STX 71 is designed to be a 18k. How does it compare?
As you can see from the basic specs, the wheels are a somewhat smaller than the 18k; yet, the STX 71 flows 5.5 lbs/min, or about 10%. In simple terms, the STX 71 will be a more responsive than the 18k while being capable of making ~10% more power.
Initial Dyno Results:
We’ve had a few testers out there, and the intal results are looking good. It looks like they are getting a little more response with a little more power vs the 18k.
Here is some plots from data logs produced by Aaron at English Racing. this is the STX 71 vs the OEM turbo. As you can see, you gain +100 whp, and give up close to nothing. It feels the same as stock.
Here is the same car on their DynoJet dyno:
Here is the result from one of our customers in Florida.
[STX 71R for FA20 Performance Performance Hypothesis [Pre-Test]]
The OEM style twin scroll turbine housing is restrictive for turbos larger than the OEM unit and our STX 67 JB turbo.
This means for our big turbos, exhaust back pressure ratios can get well beyond 2:1 that is efficient for a JB CHRA.
If you are going 5:1 or 7:1 makes it hard to build power and it wears out the journal bearings and especially the thrust bearing.
Tuners that have a good strategy to manage this backpressure can make good power with the larger STX 67+ and 71 turbos, but if they didn’t, sometimes our customers would be disappointed.
The main point of that post was that a BB CHRA actually solves all of these problems:
The CHRA can stay efficient even if the pressure ratios are 5+:1
This means, it will be a lot easier for all tuners to build power with the BB version of our turbo.
The turbo will just make more power under the curve in general
The the thrust bearing is more durable, so the CHRA will stand up to more punishment.
[STX 71R for FA20 Test Results]
We set out to actually prove if the BB version of the STX 71 would perform as well as we had hypothesized, and solve the issues we had with the JB CHRA on the larger turbos. The short version is that yes, the SteamSpeed STX 71R BB Turbo for FA20 did exactly what we thought it would. It was a lot more efficient that the JB version of a similar size; therefore, it made more power everywhere. I suspect that tuners all over will be having an easier time getting results their customers want.
Here is the dyno result. 470 whp on E50 and 410 on 91 octane pump gas, and not measured on this chart, a ton more response everywhere. Note: this is at high altitude in Utah.
[Technical Notes From Jessie at FNP]
Jessie: “Hey, First let’s go over what we saw, liked and disliked with the unit.
It’s big, if the new unit has a clearance for the oil pan and obviously ships with hardware we are good. Obviously as the prototype it is going to have clearance issues, and fitment issues. There were literally no other issues noted from Luke on install.”
SteamSpeed: This will actually be a non-issue for retail units. We have actually already resolved all fitment issues on our production 71R. The production model has a modified turbine housing with a cutout to clear the OEM oil sump without modifying it. We also designed and manufactured custom studs that we include with the 71R install kit. This is how the retail unit will work:
Sounds epic. Do yourself a favor a crack open the boost nipple when running. The ball bearing turbo sounds incredibly mean at idle. With a catless exhaust it should sound great out the tail pipe. Think diesel turbo, screaming at idle.
Response, Response, Response. This turbo is incredibly responsive compared to the previous version. Transitions in and out of boost are much quicker.
More linear boost curve via WGDC input. What do I mean? Check out this boost profile compared to WGDC on the old vs new turbo. The new unit is much MUCH more linear with interrupt cycle. This tells us the effects of back-pressure are far less of an issue with this upgraded unit. You can also see the old turbo have more “Creep” under the curve. The new unit doesn’t not do this. The compare for RPM isn’t valid, as the previous tests were done in 4th, the current in 3rd.
67+ JB WGDC
71R BB WGDC
Makes more boost in the upper RPM’s. This also is a direct causation from the upgraded cartridge. It seems to be able to operate at higher levels of back-pressure with ease.
Red JB vs Yellow BB
Less oscillation of MRP than the outgoing cartridge. Just one of those anecdotal observations, normally we see much greater fluctuations in boost on the FA20 with our incredibly fast sample rates. This unit fluctuated much less, the average was 18% realized lower fluctuations. This is a great indication of how much more air is being delivered.
Much more efficient flow from the turbo. Check out the new vs old charge air temps!
New unit held much better boost. From 1.9bar avg on the old unit at redline on 100% interrupt, to 2.3bar avg.
Output: Was increased by 12.35% over the older unit. This was also impressive as the turbo could have easily generated around 8% additional output, but the owner of the test vehicle was very specific to “Take it easy”. Based on the airflow averages and their changes, I’d say this observation is fairly precise.
Check out these airflow differences: Old Turbo 229 average max, New over 300! (it was 309 average when extrapolated up). That is an increase of 35%. Same intake, and injector scalings were used on both turbos. Compared to the stock turbo this is over 56% increase in flow!
Well, hope this helps you guys. I poured over all the data and these were the things that popped out at me.
We are excited to announce our final revision to our Focus RS intercooler! We’ve gone through three design revisions and this is the perfect design.
[Mounting & Fitment Improvements]
The first prototype core design showed huge efficiency gains vs the OEM unit; however, we saw room for improvement. In the next two prototypes we iterated and improved the end tanks and mounting tabs to further increase the efficiency of the core and ease of install.
After the intercooler had been mounted and driven nearly 1000 miles of road conditions including freeway cruising, data log pulls, dyno time, and spirited drives, we found ways to improve its mounting to the chassis vs the OE. In our final version, we increased the thickness of the mounting tab material from 3mm to 5mm and adding a perpendicular support to the lower tabs for greater strength and durability. This insures a rigid mount to radiator chassis. We also found that utilizing openings in the bumper frame to support the intercooler from the top was much more effective then the OE mounting points; the factory cooler is only suspended from the lower tabs and held vertical by the upper tabs that engage hooks into the casting of the cooler tanks. Due to the increase in weight of our cooler we knew the lower supports would never be sufficient without the extra bracing. To utilize the bumper frame, we installed a bolt and nut through the opening. This was fine for our final prototype but we look forward to using a plastic insert and screw to secure the upper mounts. This will ensure ease of installation with minimal effort.
Here you can see just how massive this thing is. There’s also a good view of the upper bumper frame mounts. This holds the weight nicely and gives great support for the cooler.
[Intercooler Performance Testing]
Our upgraded Focus RS intercooler, uses quite a bit more heat removing aluminum vs the OE unit. It is about 30-40% larger by volume and more than 50% larger by mass and surface area vs the OE unit. The performance of the intercooler core of our first prototype was stellar, so final prototype’s core remains the same.
Our Focus RS intercooler upgrade brings intake temps well below 100 degrees F. It doesn’t get terribly hot here in Washington State but we did manage to have a day with an ambient temp of 80 degrees F and a resting 101.9 degrees F. You can see in the graph how the Charge Air Temp (white line) drops rapidly when the throttle body opens. And makes its way back down to 86.7 degrees F when grabbing 3rd gear. That’s great! Many tuners are happy with and consider an intercooler “good” if it can manage to get below 100. The temp does start to climb as expected in the longer gears but as shown in the second graph the charge air temp only climbs 5 degrees to 92 degrees before lifting off the throttle. In comparison, the OE core is much less efficient. We’ve recorded increased charge temps of around 30 degrees F. That means our upgraded Focus RS intercooler around 25 degrees (6x) cooler than the OE intercooler!
Above is the data log of a 1st through 3rd and into 4th gear acceleration. The white line shows Charge Air Temp. The Charge Air Temp is around 100 degrees F when the throttle plate is closed. The induction air is moving slowly and heat from the engine heats the air. When the throttle plate opens is when the largest drop in Charge Air Temp occurs. Lots of fresh air is let in and the heated induction air passes through quickly. As the vehicle hits 3rd gear it is apparent the turbocharger is now working very hard. There is a slight increase in Charge Air Temp towards the end of 3rd gear. If this data was done without the cooler we would see. Data log continued (same log as previous graph)
Have you been wondering what our stock turbo STX 67 upgrade could do, the Results are in!!!
For this unit, we started with an OEM unit and increased the compressor wheel around 3mm on the inducer and 4mm on the exducer. The turbine section remained the same for this prototype. It is not clear if the OEM turbine housing can support a larger turbine wheel; there is not much room in there.
Our N55 turbo with similar enhancements on the cold side, and is able to make about 60-70 whp more power than the stock unit + stage 2. Lets see how our Focus RS prototype does.
We couldn’t be more pleased with the initial performance gains of our STX 67 prototype for the Ford Focus RS. Our friends at English Racing in Camas, Washington helped us reached 345 WHP and 383 wft*lbs @ 22psi (recorded with map sensor). That’s 55hp & 77 ft*lbs over the factory tune.
– Stock 2016 Focus RS
– SteamSpeed STX 67 turbo prototype
– SteamSpeed front mount intercooler kit prototype
– COBB AccessPORT
– 92 octane WA pump gas
Here are the dyno results from our car at English Racing.
What does our turbo look like vs a full “stage 2” car (FMIC, turbo-back, intake, etc.) on the same dyno? There was still the same ~40 ft*lbs torque gains, and about 11 whp on top.
Some initial thoughts:
We saw some solid gains on our mostly stock car. It was in fact the most power and torque a Focus RS has put down at English Racing on pump gas.
Since we left the turbine section as is, we didn’t expect to see huge gains on the top-end that one could probably be achieved with a larger A/R turbine housing. Accordingly 11-33 whp gains on the top end are not huge, but still a significant improvement. 40 ft*lbs on the low end is a good result. That is something you’d feel daily driving. It is clear that Ford really wanted to optimize for low end torque with this design, so it may be a challenge to overcome that housing’s limitations without replacing it all together.
All in all, there were gains around 5-15% across the entire rev band, so we are pleased with the result. It really doesn’t lose any of the benefits of the stock unit in terms of responsiveness and so on while making solid gains everywhere vs the OEM unit. As is, it is a no-downside upgrade vs the stock unit.
Here are some unboxing pictures of our new Steam STX 67 turbo for FA20 (eg. 2015 WRX). This is our design validation (DV) prototype turbo. It doesn’t have as perfect machining as the final retail version will, but I think it does give you a much clear picture of what will be included in the box.
This is a design validation (DV) prototype, so it does represent a final retail product. For example the housings aren’t fully machined in these pictures, and they are just showing OEM accessories to illustrate that this turbo is a direct replacement for the OEM turbo. The retail version will have custom fittings. The final turbo will just reuse the stock turbo oil pan.
Looking for something a little bigger? Need something a little more custom? Here is a custom made Steam STX 25G with JDM twin scroll “stock location fitment.” With that said, this turbo is big, as it probably better suited for a rotated setup.
We’ve been manufacturing Subaru-only turbochargers for some time now. That is mostly because we started doing this because we are Subaru enthusiasts. That being said, our capabilities stretch to other brands. Now we are offering a twin turbo upgrade kit for both prospective stage 1 or stage 2 applications.
This is a legitimate turbo upgrade; meaning, it is designed for the factory location. We supply a new balanced CHRA, complete with new turbine wheel and billet compressor wheel in 62mm or 67mm, depending on what your goals are, and you install that CHRA in your existing turbine housing, attach the compressor housing and all other factory accessories, such as the blow off valve and the wastegate actuator.
With supporting mods, this kit is 600whp capable (stage 2). Because we are using our 9-blade technology, the spool is still quick and peak flow is there for high rpm performance.
As one might expect, these are manufactured with the same strict attention to detail that we have exhibited in the past with all of our Subaru turbochargers. They have superior internals and excellent balance characteristics; everything one needs for high octane, high RPM enjoyment.
Want more information? Give us a call at +1 (206) 607-9149 or visit our site.
Great news, our production Steam STX 67+ turbos for Subaru WRX STI are in stock! The preorders have already started shipping, so you should see your turbos soon.
In case you were wondering, they are similar to our standard Steam STX 67 turbos, except the plus model has the next larger turbine. The should both be 350-400 whp turbos. The plus model might be a better fit for your car than the standard 67 if your car is more built, has a 2.5l motor, or otherwise is higher flowing.
Tuners strongly recommend them; we recommend them. Now we make them: Introducing the SteamSpeed BCS (boost control solenoid aka EBCS) plug and play for all turbocharged Subaru models.
Our 3-port boost control solenoid provides super high resolution boost control to dial in much more accurate tunes vs. the old OEM 2-port solenoid. Our BCS provides your tuner the tool need to safely dial in the correct boost levels, and achieve the best results possible. At the heart of our BCS is a super reliable industrial valve that is more responsive, higher flowing, more durable than stock. With our high performance BCS valve, your turbo will spool quicker, and maintain the tightest possible boost curve.
We include everything you need in the box for plug and play install. It mounts right to the stock location without modification with our custom made brackets, and clips right into the wiring harness. We even include new silicon vacuum lines and bolts so no extra trips to the parts store is needed.
Installation is a snap. Our BCS can be installed in 15 min with basic tools by most everyone.
We have used the GrimmSpeed BCS on our cars in the past, and they have worked great. Tuners we have worked with in the past recommend them, so we used their product as a measuring stick.
For our test, we simply swapped out the GrimmSpeed BCS and hooked in the vacuum lines in the exact same ports and swapped their connector for ours into the wiring harness.
How did it work out? Not surprisingly, they worked basically the same since they both are based off of nearly identical MAC industrial valves. In our testing, our higher flow barb option did out flow the GrimmSpeed BCS by about 20%. Our standard barb option flowed exactly the same. In fact, in our testing, the boost curves were identical with both BCS.
This is how our EBCS was hooked up to the waste gate.