Category Archives: PREracing News

Shift S3ctor 2016 Recap!

Great weekend at the mcminnville municipal airport here in Oregon! We lost 4th gear day one, but turned it up and shifted over the hump into 5th. Still went 177.8 mph in the standing half mile! This engine is over a year old and still keeps taking what we throw at it. Pass after pass after pass. Built and tuned by PREracing. Precision Turbo & Engine #pte6466 #turbo. Tuned on #COBB #accessport. #osgiken triple plate clutch. #turbosmart boost control. #manley internals. #preracing #fasterisbetter

Looking pretty good in the morning light!
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Zack taping up some holes for better aero.
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Ready to roll out! Was looking for 180 on this pull, came out just a tad shy.
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Last min preparations before a run.
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The leader board at the end of day #2! Second place in the sedan class but look at those speeds in AWD. Just about every one would have been a world record yesterday but 247mph in a standing 1/2 mile! Are you serous?!
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PREracing Is Now Hiring!

Like high performance cars and a great work environment? Then this is the place for you. One of Portland’s largest high performance automotive facilities is looking to add to its great team as it expands its team to include the next great team member. We are looking for a high performance automotive service technician who can bring a level of service excellence and a desire to help grow the firm.

Candidates must thrive in a fast paced technical position, display exceptional troubleshooting skills and have the ability to think outside the box. Prospective employees must demonstrate a deep knowledge and understanding of aftermarket high performance automotive systems.
Please apply at the link below and complete the Core Values Index assessment when applying for this great opportunity.

Responsibilities

  • Keeps equipment available for use by inspecting and testing vehicles; completing job specific tasks such as, engine tune-ups, trouble shooting, engine diagnostic and other job related tasks
  • Maintains vehicle functional condition by listening to operator complaints; conducting inspections; repairing engine failures; repairing mechanical and electrical systems malfunctions; replacing parts and components;
  • Verifies vehicle serviceability by conducting test drives; adjusting controls and systems.
  • Complies with state vehicle requirements by testing engine, safety, and combustion control standards.
  • Maintains vehicle appearance
  • Maintains vehicle records by recording service and repairs.
  • Keeps shop equipment operating by following operating instructions; troubleshooting breakdowns; maintaining supplies; performing preventive maintenance; calling for repairs.
  • Contains costs by evaluating service and parts options.
  • Keeps supplies ready by inventorying stock;
  • Updates job knowledge by participating in educational opportunities; reading technical publications.
  • Accomplishes maintenance and organization mission by completing related results as needed.
  • Other duties as assigned

Preferred Qualifications

  • 5 years or more experience
  • ASE Certifications (encouraged)
  • Automotive Technician
  • Diagnosis and repair of EFI Vehicles
  • Forced Induction Systems
  • Dealership Experience
  • Welding and Fabrication
  • EFI Personal Project

If you are interested in this exciting opportunity, please click here to apply.

Stock Location Turbo Showdown!

I will start with the background on what motivated us to do this test. We see a lot of different cars with a lot of different parts go toe to toe on our all wheel drive dyno dynamics dynamometer, and with no two cars being the same it can be hard to pin-point just what turbo really throws down the best power. A customer came to us with a very specific goal. He wanted us to figure out what turbo would make him at least 450whp and 450wtq. We decided to test out a few stock location turbos… Nine of them in total! Retail value of the tested turbos was a somewhat staggering 15,223 dollars!!!

Here is a list of the conditions that all turbos were to be tested under:
• All had to be true bolt on stock location turbos, meaning 2.5″ inlet and ihi flange.
• All turbos were tested with a Turbosmart 45mm external wastegate containing a 14psi spring to ensure that internal gate inconsistencies could not affect the performance.
• Same car, same tank of E85, no changes to any other mechanical systems.

PARAMETERS:
• We allowed a 15 minute cool down before any final numbers were recorded, two runs back to back, highest run recorded.
• We monitored the Carbon Monoxide level in the room constantly to make sure exhaust gases were not building up to unacceptable levels in the dyno cell.
• All turbos were run at “pump gas” friendly 21psi, as well as 25psi high boost tune. We did our best to record all results within +/- .5psi.
• Air fuel ratio was run at as close to 12:1 as we could manage on every recorded run.
• All runs are weather corrected since testing was done over multiple days.

THE CAR:
The car used for this test was a 2005 Legacy GT. This is a quick list of mods, if nothing is mentioned assume it is stock. All dyno pulls were made on a single tank of E85 confirmed at 82% ethanol.

ENGINE:
• CP 9.0:1 forged pistons
• Manley H-beam rods
• Manley 37mm intake valves
• Manley 33mm exhaust valves
• Manley springs and retainer kit
• GSC s1 cams
• Tomioka Racing Unequal Length Header
• ETS FMIC kit
• Tomioka Racing turbo inlet tube
• TGV deletes
• 700whp fuel system
• K&N 2.75” intake
• Cobb access port was used for tuning in speed density.

THE TEST:
I just want to clear up one thing before we get to the numbers. Some of the turbos tested only have results for 21 psi because this was the highest boost level we could achieve on these turbos. Wastegate duty cycles were at 95% on these turbos. All of the gt28 based turbos, the Tomioka and the Steam speed included really seemed to struggle with this problem. I would suggest not buying either of these if you plan on running any more than 21psi.

TOMIOKA GT28 – 21PSI-TAPERING 19PSI

IMG_7458

• DYNO ROOM TEMP = 66 *
• HUMIDITY = 77%
• BARO = 30.0
• WEATER CORRECTION FACTOR = .975
• CO = LESS THAN 100PPM
• MAX POWER = 412WHP
• MAT TORQUE = 394WTQ
• RETAIL PRICE = $1695

REVIEW:
This one really fell short on our testing. It didn’t spool very well for a small framed turbo, with boost finally peaking all the way up around 4700rpm. Also notice the strange shape of the boost curve. This was a problem we noticed with both of the gt28 based turbos we tested. This turbo could not reach above 21psi either, it does however have a decent peak power output for such a low boost level. Fitment is good, and the kit comes complete with everything needed for install.

TOMIOKA GTX2876R - MAX (21PSI) (2)

TOMIOKA GTX2876R - MAX (21PSI)

BLOUCH DOMINATOR 2.5XTR 10CM 21PSI TAPERING 19PSI

IMG_7461

• DYNO ROOM TEMP = 61 DEGREES
• HUMIDITY = 77%
• BARO = 30.05
• CO = LESS THAN 60PPM
• WEATHER CORRECTION FACTOR = .970
• MAX POWER = 426WHP
• MAX TORQUE = 400WTQ
• RETAIL PRICE = $1799

REVIEW:
All of the dominator turbos we tested performed well. This was the biggest we tested, and it was optioned with the 8cm housing. For its size it spooled pretty well, and it made great power on both low and high boost. If you’re looking for maximum horsepower out of your 2.5 inlet, this is your best bet.

BLOUCH 2.5 XTR 10CM - 21PSI (22)

BLOUCH 2.5 XTR 10CM - 21PSI (23)

BLOUCH DOMINATOR 2.5XTR 10CM 26PSI TAPERING 22PSI

IMG_7461

• DYNO ROOM TEMP = 64 DEGREES
• HUMIDITY = 75%
• BARO = 30.05
• CO = LESS THAN 60PPM
• WEATHER CORRECTION = .969
• MAX POWER = 463.5WHP
• MAX TORQUE = 455WTQ

BLOUCH 2.5 XTR 10CM - MAX PSI

BLOUCH 2.5 XTR 10CM - MAX PSI (2)

BLOUCH DOMINATOR 1.5XTR 8CM 21PSI TAPERING 19PSI

IMG_7461

DYNO ROOM TEMP = 66 DEGREES
HUMIDITY = 71%
BARO = 30.05
CO = LESS THAN 32PPM
WEATHER CORRECTION = .976
MAX POWER = 418.3WHP
MAX TORQUE = 398WTQ
RETAIL = $1699

REVIEW:
This is just a good turbo on all counts, spools well, makes great power and looks the best out of all the others in its size. We tested this in both housing sizes, this 8cm version would be best suited to stock engines cars with a relatively low power band.

BLOUCH 2.5 XTR 8CM - 21PSI

BLOUCH 2.5 XTR 8CM - 21PSI (2)

BLOUCH DOMINATOR 1.5XTR 8CM 25PSI TAPERING 21PSI

IMG_7461

• DYNO ROOM TEMP = 67 DEGREES
• HUMIDITY = 71%
• BARO = 30.00
• CO = LESS THAN 130PPM
• WEATHER CORRECTION = .970
• MAX POWER = 440.9WHP
• MAX TORQUE = 431WTQ

BLOUCH 2.5 XTR 8CM - MAX PSI (2)

BLOUCH 2.5 XTR 8CM - MAX PSI

STEAM SPEED STX71R BALL BEARING 21PSI TAPERING 19PSI

IMG_7455 - Copy

• DYNO ROOM TEMPERATURE = 62 DEGREES
• HUMIDITY = 87%
• BARO = 29.77
• CO = LESS THAN 80PPM
• WEATHER CORRECTION FACTOR = .985
• MAX POWER = 407WHP
• MAX TORQUE = 382WTQ
• RETAIL = $1599

REVIEW:
This is another one of the gt28 based ball bearing turbos, and just like the Tomioka it fell short of expectations. It could not reach a target boost higher than 21psi, and made just slightly less power than the equivalent from them as well. Another note on this, they ship the turbo with steel braided coolant lines with adapters to barb. The barbs are not the correct size for the stock Subaru 1/2 coolant hoses. So I had to do some adapting to make it work as intended. This makes for a very “un-clean” installation.

STEAMSPEED STX71R - MAX (21PSI) (2)

STEAMSPEED STX71R - MAX (21PSI)

TOMEI M8265 21PSI TAPERING 19PSI

IMG_7453

• DYNO ROOM TEMP = 61 DEGREES
• HUMIDITY = 86%
• BARO = 30.05
• CO = LESS THAN 100PPM
• WEATHER CORRECTION FACTOR = .960
• MAX POWER = 430.9WHP
• MAX TORQUE = 405WTQ
• RETAIL = $1490

REVIEW:
We have used this turbo in the past on some customer cars, and it’s a solid all around choice. It spools reasonably well for the power, and makes good power on pump gas boost levels. The other nice thing about this kit is it includes a new top mount intercooler elbow, as well a couple different options for feed lines. Also notice that this turbo did not pick up much power at higher boost. It’s just running out of its high efficiency range up top to make the big numbers, but the torque did swell nicely on the spike.

TOMEI M8265 (2)

TOMEI M8265

TOMEI M8265 25PSI TAPERING 20.5PSI

IMG_7453

• DYNO ROOM TEMP = 61DEGREES
• HUMIDITY = 86%
• BARO = 30.05
• CO = LESS THAN 100PPM
• WEATHER CORRECTION FACTOR = .960
• MAX POWER = 447WHP
• MAX TORQUE = 438WTQ

TOMEI M8265 - MAX PSI

TOMEI M8265 - MAX PSI (2)

STEAM SPEED STX67+ (td06) 21PSI TAPERING 19PSI

IMG_7455

• DYNO ROOM TEMP = 65 DEGREES
• HUMIDITY = 85%
• BARO = 30.00
• CO = LESS THAN 60PPM
• WEATHER CORRECTION FACTOR = .971
• MAX POWER = 428WHP
• MAX TORQUE = 405WTQ
• RETAIL = $1349

REVIEW:
This was actually one of the surprise turbos in the bunch that we tested. It spooled nearly identically to the Dominator 1.5XTR 8cm, but did not produce the same power per pound of boost during that time. This turbo made strong numbers on both low and high boost, and has one of the best price points of the bunch.

STEAMSPEED STX67+ - 21PSI (2)

STEAMSPEED STX67+ - 21PSI

STEAM SPEED STX67+ (td06) 25PSI TAPERING 19PSI

IMG_7455

• DYNO ROOM TEMP = 65 DEGREES
• HUMIDITY = 85%
• BARO = 30.00
• CO = LESS THAN 60PPM
• WEATHER CORRECTION FACTOR = .971
• MAX POWER = 434.3WHP
• MAX TORQUE = 435WTQ

STEAMSPEED STX67+ - MAX

STEAMSPEED STX67+ - MAX (2)

STEAM SPEED STX67 (td05) 21PSI TAPERING 19PSI

IMG_7455 - Copy (2)

• DYNO ROOM TEMP = 67 DEGREES
• HUMIDITY = 82%
• BARO = 30.00
• CO = LESS THAN 100PPM
• WEATER CORRECTION FACTOR = .994
• MAX POWER = 428WHP
• MAX TORQUE = 418WTQ
• RETAIL = $1249

REVIEW:
This is the td05 exhaust housing version of the STX67. It could not produce above 21psi because of the reduced turbine size but It did however make identical power to the larger turbine version, and spool difference is negligible. I recommend spending the 100 bucks to go to the td06 version unless you’re running a 2.0l engine.

STEAMSPEED STX67 - MAX

STEAMSPEED STX67 - MAX (2)

FORCED PERFORMANCE HTA71 21PSI TAPERING 18

IMG_7454

• DYNO ROOM TEMP = 67 DEGREES
• HUMIDITY = 86%
• BARO = 29.76
• CO = LESS THAN 100PPM
• WEATHER CORRECTION FACTOR = .995
• MAX POWER = 415WHP
• MAX TORQUE = 408WTQ
• RETAIL = $949

REVIEW:
The HTA71 has the smallest housing sizes of any of the turbos we tested. It spools reasonably well and makes pretty solid numbers at pump gas boost levels. We did pretty much max it out during our tests at 415whp. That being said, it still has the best power per dollar ratio out of everything we tested. If you’re looking for around 400whp and on a budget then this thing can get it done.

FP HTA71 - 21PSI (MAX)

FP HTA71 - 21PSI (MAX) (2)

BLOUCH 1.5XTR 10CM 21PSI TAPERING 19PSI

IMG_7461

• DYNO ROOM TEMP = 70 DEGREE
• BARO = 30.02
• HUMIDITY = 86%
• CO = LESS THAN 100PPM
• WEATHER CORRECTION FACTOR = .984
• MAX POWER = 439WHP
• MAX TORQUE = 445WTQ
• RETAIL = $1699

REVIEW:
This turbo was not originally part of our test lineup, but because of the power output of the 2.5XTR at high rpm, we were thinking this might deliver the best of both worlds for our customer. His power goals were 450wtq/450whp with awesome spool. Well, it delivered. With the headwork this car has I believe that the 8cm housing is just a bit too small. Because of this the 10cm version was able to spool just slightly faster, and absolutely kill it on the top end where the turbine housing was continuing to flow well. Hands down this was the best turbo of the bunch, especially on our test car.

BLOUCH 1.5 XTR 10CM - 21PSI (2)

BLOUCH 1.5 XTR 10CM - 21PSI

BLOUCH 1.5XTR 10CM 25PSI TAPERING 21PSI

IMG_7461

• DYNO ROOM TEMP = 70 DEGREE
• BARO = 30.02
• HUMIDITY = 86%
• CO = LESS THAN 100PPM
• WEATHER CORRECTION FACTOR = .984
• MAX POWER = 472.8WHP
• MAX TORQUE = 472WTQ

BLOUCH 1.5 XTR 10CM - MAX

BLOUCH 1.5 XTR 10CM - MAX (2)

CLOSING:
Overall there are a lot of solid performers in this group, and most are likely not to be disappointed with the majority of these choices. One thing I will say about these graphs is to pay close attention to power output at the very beginning of the graph. There is a big difference in the way these turbos drive around town. The gt28’s are just dogs anywhere out of boost, while the most responsive of these being the once again the Dominator 1.5XTR, especially the 8cm version. Please keep in mind also that if you are looking for even more power, that the real restriction on these turbos was the 2.5” inlet diameter. There are countless other options when you step up to the 3” inlet that will put down over 500whp. Hopefully this will help some of you make a more educated decision when spending over $1000 bucks on your next power adder!!!

PREracing becomes an EcuTek Master Tuner!

PREracing has been selected by EcuTek to become an EcuTek Master Tuner!  Becoming a Master Tuner allows us to sell and custom tune ProECU tuning kits. We can now also remotely tune vehicles anywhere in the world.

There are lots of useful and advantageous features to the EcuTek products. It features flex fuel support for most vehicles, the custom maps feature allows you to setup nearly any engine safety function.  This includes but isn’t limited to; oil pressure protection, oil temperature protection, coolant temp protection, air / fuel ratio protection… you get the idea. The custom maps feature can also be used to program traction control and closed loop boost control. The uses are vast.

EcuTek allows map switching without a handheld device (usually done through the cruise control switch). This switch can also be programmed for on-the-fly boost control, cam control, launch rpm, or anything else you may want.

EcuTek is fast and easy to use. An ECU can be read and modified in as little as 30 seconds! Lets face it. Dyno time is expensive! The faster the process takes the less you have to pay on the dyno.

  • License: $350
  • Cable: $400 (Not required. Can be purchased for at home tuning and data logging.)
  • Tune: $400-$600 (Vehicle dependent)

Being EcuTek master tuner not only allows for remote tuning and calibrations, but it opens us to a wide number of new vehicles we can tune.

What vehicles do ProECU Tuining Suites Support?
Subaru Tuning Suites – Supporting over 850 vehicles *****This includes almost all Naturally Aspirated models after 2000*****
Mitsubishi Tuning Tools – Supporting over 390 vehicles
Mazda Tuning Tools – Supporting over 280 vehicles

Nissan Tuning Tools – Supporting over 380 vehicles

To reprogram the ECU, the EcuTek programming interface is simply plugged into the diagnostic socket of the car. Some of the supported vehicles can then be reprogrammed in under 25 seconds!

Unlike other ‘chipping’ solutions, ProECU Tools require no soldering and no physical access to the ECU – an altogether quicker, cleaner and more reliable method of tuning. Rather than spending time soldering and desoldering hair thin chip legs, the tuner’s time can now be spent more productively, with less time spent wiring things up and more time actually improving the mapping of your vehicles car.

Tomioka Racing Subaru Turbo Sale! ENDS 11/30/2015

Extra, Extra! We’re INSTALLING and TUNING Tomioka Racing turbos (excluding twin scroll) on all supporting Subaru’s for as low as $1050! That’s about the equivalent of a $200 install & tune with the purchase of a turbo! This promotion does not include the install or purchase of any additional aftermarket parts such as uppipes, downpipes, injectors, etc, that may be required to properly run your desired setup. It is solely the Turbocharger, gaskets, and any hardware used in the BOLT ON installation of the Tomioka turbocharger.

Now that’s scary. Interested? Call 503-619-0055 or send an e-mail to info@preracing.com

Below is a list of Tomioka Turbos that apply to this promotion!

TD05-16G: $1050.00
TD05-18G: $1150.00
TD05-20G: $1300.00
TD06-20G: $1600.00
TD05-GT28 Billet: 2095.00
Hybrid VF54: $1950.00
Hybrid GT28 Billet: $2095.00
Hybrid GT30 Billet: $2495.00
TD05-16G Billet: $1150.00
TD05-18G Billet: $1250.00
TD05-20G Billet: $1450.00

Each Tomioka Turbocharger comes packaged the componets below and will be installed

  • Turbocharger
  • Actuator
  • Oil Pipe
  • Water Pipe
  • Gaskets
  • Hardware Kits

TURBOCHARGER SIZING GUIDE
VIEW TURBOS ONLINE

Q&A:

  1. If I need supporting parts, will the install costs be covered by the promotion?
    •  No. Any extra parts needed (e.g. Downpipes, upipes, injectors) will be installed at an additional cost.
  2. If my car currently does not pass pre-dyno inspections, what will happen?
    • Before your car can be tuned, you first must pass a pre-dyno inspection. If you car does not pass, additional work outside of the conditions of the promotion will need to be done.
  3. If I already have a Tomioka Turbo, can I get the free tune/install?
    • No, the promotion is WITH the promotion of a Tomioka Turbo in the list above, you will receive free installation of the turbocharger and a tune for it.
  4. Is the tune custome or an OTS map?
    • Custom. Each vehicle gets the same dyno love as everyone else regardless of the setup.
  5. Does the turbo promotion include all hot/cold piping, waste gate,bov, fmic,misc parts?
    • No, This amazing package includes the Turbo Billet internal adjustable actuator, install, gaskets and tune via Open Source or Cobb Access Port for a Subaru. Fuel upgrades, Intercooler, exhaust or other modification parts are sold separate.
About Tomioka

Using experiences learned on the track and feedback from other tuners, the Tomioka Racing development team has extensive knowledge in turbo technology. Which has allowed them to provide turbo kit solutions for users who require smooth power delivery for the street and enjoyable sport driving. These turbo kits have been designed to offer a boost in power without sacrificing the response found in stock turbos and provide extra performance and without additional cost.

PREracing BBQ & Dyno Day – OCT 24th!

Subaru friends! Come hangout at the shop for another family friendly gathering with great food, nice cars, and awesome people! This may be the last time we can do this until spring so don’t miss out! Our dyno is lowered friendly, oh, and lifted too ;). No need to worry, we got you (Especially you stock guys). We’re expecting some high horsepower Subaru’s in the 400-500whp+ range to be showing up. It’s going to be what some call a HOOT! Can’t wait to see you all there!

FACEBOOK EVENT PAGE

3 pulls for 40$. Roughly 25 cars will be dyno’d if all goes well. First come first serve, so get here early!

Dyno pulls will start at 9:00am and will go to 5:00pm with a break somewhere in between. The BBQ’s will be fired up around 11:30am! We mentioned that the food is FREEEEE right?

Here’s some photos of the last dyno day we had!

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Fun with Corn: 2015 Subaru WRX e85 Ethanol Conversion

E85 is the shorthand way of saying 85% ethanol fuel and 15% gasoline or other hydrocarbon fuel. This fuel is typically made by distilling corn sugar into alcohol then blending it with gasoline to the desired ratio which can actually be anywhere from 53% to 83% ethanol according to government regulations.  There is some chemistry here that we won’t go far into but basically gasoline burns at a stoichiometric (complete combustion reaction) ratio of 14.7:1 with oxygen (it takes 14.7 oxygen molecules to completely burn one gasoline molecule) where as e85 burns at a rate of 9.85:1 with oxygen. The difference would result in a 67% ratio of gasoline to e85 except our gasoline is now actually e10 which has a stoich ratio of 14.08:1 for a ratio of 70%. This basically means it takes 30% more e85 than premium gas to burn the same amount of oxygen which should result in 30% less fuel economy.  The simple math, if mileage is 30mpg on gasoline, after switching to e85 mileage should decrease to 20mpg. We’ll have more on that later.

In order to convert the 2015 WRX to ethanol based fuels one must do the following steps:

  1. Drain the tank of all gasoline; do this by driving or using a pump. Unfortunately there is no drain on the bottom of the tank to make this super easy like older Subaru vehicles. We can’t all be perfect!
  2. Fill tank with ethanol; through the fill neck, just like pump gas.
  3. Tune vehicle for e85; this can be as simple as changing one table in the tune file although many tables must be changed for optimal results and maximum horsepower.
  4. Drive

Yes, it’s that simple. No need for injector changes, fuel pump changes, expensive flex kits and the like. The reason for this is the vehicles ability to step up pressure in the direct injection system to compensate for the additional fuel demand. By raising pressure the volume flow rate is increased.

Fuel Economy:

When discussing the switch to ethanol fuels the first thing out of most people’s mouth is “but that fuel economy though.” Well, this is the first time I think I’ve ever been able to proudly answer that question with “who cares.” First off, the fuel economy gauge in the 2015 WRX is woefully inaccurate. Hopefully soon COBB will release scalar factors for it so we can rein it back in but at the moment it’s extremely liberal. I guess if the gauge says 34mpg it must be true! (but it’s not) Actually at one point we observed 34.5mpg sustained on the gauge while running e85, clearly a miscalculation. Even on gasoline and a completely stock tune it likes to show 32-33mpg when if the math is done results show closer to 28mpg.

E85 Ethanol Fuel: 23.33 mpg measured (not observed) on the 349 mile trip to Spokane, WA from Portland, OR. Please note, this was done on ONE tank of fuel and while we actually ran out at our destination of Spokane County Raceway, we did make it. Actual measured ethanol content in this test was 83% ethanol which seems to be pretty average for Jay’s Garage in Portland where we source our ethanol.

92 Octane (E10 Unleaded Gasoline): 28mpg highway rated, 28.5 measured (not observed) on the 349 mile trip home from Spokane, WA to Portland, OR.

The surprising thing is that we only saw a decrease of 18.3% in fuel economy while running on e85. Mathematically the fuel consumption for e85 fuel should be much higher, upwards of 30% more in fact. There are two primary factors that caused this variance in expected vs. measured fuel economy, direct injection and high compression. These factors allow the engine to run extremely efficiently at low rpm making more torque for the same given air mass coming into the engine. This extra torque means the engine doesn’t have to work as hard to maintain engine RPM, so at 75mph in 6th gear the actual engine load is significantly lower on the ethanol fuel than the gasoline fuel.  Given the cost of e85 being typically 15-20% lower than premium unleaded the cost to run e85 in this car is basically a wash and with the added benefits it seems like e85 is definitely the way to go. Too bad the bio-fuel infrastructure in the Portland area (really the whole Pacific Northwest) is basically non-existent making availability the only real hurdle here to overcome.

Ethanol isn’t the answer for all our nations’ fuel problems but it’s a no brainer that we need to reduce our dependency on foreign oils.  With more and more vehicles coming to market with direct injection, most having significantly higher compression, I really hope support for ethanol grows and new engineered bio-fuels show their face in the years to come.

 Horsepower!:

Now for the section everyone actually cares about, the POOOOOOWWWWWAAAAA! Ethanol fuels contain a few properties that make them absolutely insane for making big power numbers.

Knock Resistance – The first of these properties is octane also known as knock resistance. This property is basically the fuel’s resistance to combustion which actually makes it burn slower. A slower burn means we get to start the burn sooner before the combustion becomes uncontrolled. This advance in ignition timing allows for serious power gains even at the same boost levels as gasoline.

Cool Combustion – Along with this slower burn we have really cool (literally) thermal characteristics of all alcohols, they burn very cold. Colder burn means lower engine temperatures and lower exhaust gas temperatures. This cooling effect is very important on the 2015 WRX due to the high intake temperatures it tends to see due to its poor intercooling design.  This is another reason the engine became so much more efficient on the switch to e85, even sustained highway driving saw lower manifold inlet temperatures by about 8 degrees on two days with the same ambient temperature.

Evaporative Cooling – While in boost this cooling effect is amplified because the ethanol cools the charge similar to an intercooler through an evaporative cooling effect. The basic laws of thermodynamics state that colder air is a denser air (or charge as we call it), denser charge means more oxygen molecules to burn at the same boost level which means more horsepower!  See where we’re going here?

These cooling effects along with the increased octane allow us to run more boost than would be safe on gasoline. Turning the boost up results in more oxygen molecules in the air charge, the more air forced into the engine to combust, the more fuel we can add, the more power we can put to the wheels. After turning up the boost, remapping the ignition timing, and adjusting the air fuel ratios we ended up with a grand total of 274.1 wheel horsepower and 282 ftlb of torque! That’s a peek gain of 43.5 horsepower and 25ftlb of torque by changing nothing but the fuel and adjusting the tune. More important is the overall gains under the graph which can be seen in the picture below. Torque is considerably higher throughout the entire pull which equates to seriously faster acceleration.  How much faster? We dropped almost an entire second in the quarter mile!

15 WRX STOCK TRIM WITH PRE TUNE

This graph shows the 2015 WRX in stock trim with the factory tune on pump gas in red and a PREracing custom COBB Accessport tune on e85 in blue. Substantial horsepower and torque gains can be seen throughout the entire powerband and power delivery is much more smooth.

Cobb Accessport V3 – 2002-2005 WRX

Cobb Accessport V3 – 2015 WRX & STi / 2014-2015 Forester XT

Cobb Accessport V3 – 2008-2014 WRX & STi / 2007-2012 Legacy GT / 2007-2009 Forester XT

Cobb Accessport V3 – 2006-2007 WRX / 2004-2007 STi / 2004-2006 Forester XT / 2005-2006 Legacy GT / 2005-2006 Outback XT

Fastest quarter mile pass on e85 : 12.989 @ 106.25 mph.

The only change was the addition of e85 fuel and a custom tune. Interestingly other passes “soft launching” had mph up as high as 107.28. So far on e85 we haven’t been able to run a true “clean” pass with a good hard launch because of the next weakest link in the vehicle, the rear end. The fastest time we have run bogged pretty hard off the line. With a good hard launch and ethanol we’re confident this vehicle has a mid 12 second pass in it. Stay tuned for that!

Overall this 2015 WRX is a completely different vehicle when fed with e85. Throttle response is crisper, acceleration is significantly improved, and the whole feel of the car is improved.  We really like the way everything came together and hope to really show off the platforms capabilities in the near future.

The downside to Racing:

With all racing comes the risk of broken parts and as we have turned up the power we’ve already started finding weak links. The first serious issue we’ve run into is a result of the hard launches. Both times we’ve been to the dragstrip and launched the car with ethanol in the tank we came home with a broken rear end.  Both times the spider gears in the differential shattered during a launch causing catastrophic differential failure.

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The car is just too heavy with too much torque for the tiny Subaru R160 rear differential. The STI models have an upgraded R180 differential and beefier axles to help with this issue but unfortunately the WRX was not so lucky. We have looked into different options and think we will probably go with the Quaife differential out of England. This will remove the vehicle from its “physically stock” status but it’s getting tiresome replacing these rear ends. Hopefully the Quaife will hold together and we can get a few hard launches on the all stock engine components to really show what this new direct injected corn fed beast can do.

Final Thoughts:

These rear end issues seem to be isolated to drag launches as to be expected and fortunately there is a new form of racing that’s gaining momentum throughout the country, roll racing. This is where the race is started while already moving at a set mph, usually 30-40. This reduces drivetrain stress but still provides the exhilaration of racing head to head down a drag strip or other track. We had the great opportunity to sponsor such an event at the Spokane County Raceway in Spokane Washington. From a roll this little WRX did not disappoint and while usually outgunned it held its own against quite a few opponents with a whole lot more horsepower. Trapping as high as 121.43 on the roll the WRX performed admirably. Few people could believe it was a completely stock powertrain with just a tune and it definitely earned some respect. We can’t wait to be part of future roll events as we watch this new aspect of the sport grow.

Thanks for reading, until next time.

~Erich

The new 2015 Subaru WRX, stock, tuned, and track tested!

We recently got our hands on a brand spanking new 2015 Subaru WRX and couldn’t resist the urge to do some testing. This exciting new platform features the a 2.0 liter engine like the WRX of old but with quite a few major differences. The new car features a twin scroll low mounted turbocharger, direct cylinder injection, a completely redesigned engine, and a 6 speed transmission. Considering this platform is likely the future of Subaru we decided it would be a great vehicle to do some serious testing.

In this article we test this car in it’s purest “stock” form. We explore the capabilities of the car exactly as Subaru designed while making changes to only the tune.

Stock Baselines

It’s always a good idea to get a baseline when modifying anything so you know that your modifications are working as intended. To baseline our new 2015 Subaru WRX we decided first to put around 1000 miles on the chassis to break it in. After that it was off to the dyno for initial testing.

On the stock tune the vehicle put down 197.7 whp and 228 ftlb tq. A little shy of what we had expected from drivetrain loss over the advertised 268 horsepower. We decided to reset the ECU as often Subaru’s like to learn lower timing. This yielded slightly higher numbers on the first pull but on subsequent pulls we were back down to the previous numbers. The thing that was the most shocking was the boost curve, or rollercoaster rather. The boost came in spiking to nearly 20psi on the dyno, then back down to xx psi then back up before finally tapering off towards redline. This boost inconsistency was present on all pulls done with the stock tune. Regardless it was time for some tuning. This thing needed it bad.

Stock 2015 WRX Baseline Dyno Graph

Quick references: Actual vehicle weight 3,307 lb. Weight with driver 3,600 lb even. Fuel used is 92 octane e10 pump gas. The WRX has absolutely no electrical or mechanical modification for stock tests and only a COBB Accessport tuner for tuned tests.

Tuning COBB Stage 1

For tuning we are using the COBB Accessport and COBB Tuning Access Tuner Pro software which is a tried and true tuning tool for Subaru and other platforms. They also have excellent customer support as well as full datalogging capability which is extremely important for tuning and making changes especially in a racetrack environment. While laptop loggers and tuning solutions are available, the Accessports ease of use and feature rich interface make it the ideal choice.

Cobb Accessport V3 – 2002-2005 WRX

Cobb Accessport V3 – 2015 WRX & STi / 2014-2015 Forester XT

Cobb Accessport V3 – 2008-2014 WRX & STi / 2007-2012 Legacy GT / 2007-2009 Forester XT

Cobb Accessport V3 – 2006-2007 WRX / 2004-2007 STi / 2004-2006 Forester XT / 2005-2006 Legacy GT / 2005-2006 Outback XT

To get the party started we loaded the off the shelf (OTS) 91 octane stage 1 map onto the ECU. After letting it run for a bit and running it through some gears on the dyno to allow the ECU to learn we did the first pull. Immediately the IAM (dynamic advance multiplier) dropped down below 1 which is an indication of timing and knock issues. Another pull and the IAM stayed the same. 3rd pull and the IAM climbed back up a little. Horsepower on the COBB OTS Stage 1 map was 223.0 whp and 249 ftlb, a healthy gain over the stock rating. Additionally the boost was much more stable which translates into a smoother power and torque curve. Driving the car on the COBB Stage 1 map is much more exciting and predictable than the stock tune. Power comes on smooth and pulls hard to about 5500rpm. The throttle feels much more linear and less bottom loaded than the stock tune. All-in-all the car is actually easier and significantly more fun to drive.

2015 WRX COBB OTS S1 Tuned

An interesting note, while the ignition advance multiplier (cars adaptive timing) is defaulted to 1.0 in the Stage 1 map, it quickly dropped to 0.500 while driving indicating over advanced timing. After a couple full throttle pulls the IAM climbed up to 0.680 where it wanted to stay. It seems these direct injection cars are especially prone to knock at part throttle, more on that later.

Tuning PREracing Custom Stage 1

Since we have full tuning capabilities with the Accessport using the Access Tuner Pro software we wanted to see if we could make any gains over the COBB off the shelf stage 1 map. Adjusting the air fuel ratio slightly and making pretty significant timing curve changes we were able to squeak out 7.6 more horsepower to the wheels for a total of 230.6 wheel horsepower and 257 wheel torque. Not a huge gain but the more significant thing was that we did it by reducing overall ignition timing through the whole map and lowering boost. These two indicators show that the compression of this engine is too high for the boost and timing that was requested from the COBB 91 octane Stage 1 map. This made sense considering the vehicles ignition advanced multiplier (IAM) had dropped while driving the car on the COBB map.

2015 WRX PREracing S1 Tuned

When you look at the overlay of the PREracing custom map and the COBB S1 map you will notice one thing. The COBB map makes more power above 6000rpm than the PREracing map. The reason for this is that while the ECU is seeing knock and actively pulling timing during this area however the total timing is still higher than our tune. This area almost always knocks the IAM down on the COBB map if it hadn’t already dropped. In order to keep the IAM up we decided to reduce timing in that area on the PREracing tune so the ECU doesn’t see any knock and therefore doesn’t drop the IAM down. This effectively reduces where you should shift the car from stock redline of 6500 down to about 6100. We felt that this was better for longevity of the engine to not knock at all instead of knocking and having the ECU pull timing. We focus our tunes on raising peek power and power under the curve which is achieved well before 6500 rpm on this motor and for the sake of engine safety there is really no reason to rev the engine past 6100 rpm.

2015 WRX S1 Horsepower Overlays

Unfortunately once driving even with our lower timing and boost targets the WRX’s computer still wants to pull timing in places. While this automatic reduction wasn’t as severe as the COBB Stage1 map it was still more than we like to see. The easiest solution here is to add octane but unfortunately the pumps here in Portland only deliver 92 octane fuel not the 93 that is available in many parts of the country.

To the racetrack!

2015 WRX

Since the car is completely stock still we wanted back to back to back comparisons of stock to COBB Stage1 to PREracing Custom Stage1 so off to the track we went. The local Portland International Raceway dragstrip hosts quarter mile staged and timed drag races just about every Friday and Saturday night from April to September and is perfect for our testing needs. While our racetrack is essentially at sea level on the day of testing the effective density altitude of the air was 1512ft. This means that under standard atmospheric and temperature conditions we were effectively breathing as if we were racing at 1512ft, not sea level. The exact weight of our stock 2015 Subaru WRX was 3,307 lb and with driver we’re at an even 3,600 lb.

First pass we loaded the stock tune back onto the WRX, drove around for a few min to allow for ECU adjustments, and staged the car to race. Launching a Subaru WRX can be a bit challenging as it is very easy to bog the engine on takeoff which will cause horrible times. Fortunately we practiced a few launches in the shop parking lot and figured out a technique that provided for the most part ~1.8 second 60ft times.

Times for stock tune

Best Stock Pass

While some reviews put the car at 13.8 seconds at 100-101 mph our car on this day clearly was making less horsepower or weighs more than the cars tested, however these are baseline numbers for showing gains and were consistent enough for that purpose.

  • 60ft                        1.899
  • 1/8 ET                    9.067
  • 1/8 MPH              76.62
  • 1/4 ET                    14.208
  • 1/4 MPH              94.63 – clean pass

COBB Stage 1 Runs

After we felt we had a good cross section of baselines for stock we loaded COBB OTS Stage 1 tune onto the WRX and gave that a few passes. Immediately the difference was noticeable as we gained 3.27 mph for a total of 13.950 seconds at 97.9 mph. As on the street the IAM was dropping during the pulls and in 4th gear the car felt pretty flat.

Best COBB OTS S1 Pass

  • 60ft                        1.886
  • 1/8 ET                    8.864
  • 1/8 MPH              77.63
  • 1/4 ET                    13.950
  • 1/4 MPH              97.90     – Clean pass, IAM dropped slightly around 2nd gear

PREracing custom Stage 1 tune runs

As before with the OTS map we loaded the PREracing Custom Stage 1 Tune and gave it a few passes. The WRX responded well to the additional torque from the PREracing tune posting faster 1/8th ET and 1/8 mph.  3rd gear didn’t feel nearly as flat as the COBB tune and most importantly the IAM did not drop during the run.

Best PREracing custom S1 Pass

  • 60ft                        1.864
  • 1/8 ET                    8.801
  • 1/8 MPH              78.18
  • 1/4 ET                    13.869
  • 1/4 MPH              97.75 – Clean pass

The difference in ET with the PREracing map was primarily from changes to torque delivery which allows more power “under the curve” than the COBB OTS map. Since peek-for-peek horsepower was very close the final MPH was also very similar but the elapsed time was a noticed difference. For the day both the highest MPH and fastest Elapsed Time were from the PREracing custom map.

Final Thoughts

After all this testing two things are very apparent. One, the car needs better fuel. The complete lack of ignition timing really seems to be holding this engine back. Two, back pressure seems really high. Boost literally falls on its face as RPM increases and while it gives a decent amount of torque for a 2.0 liter engine it severely limits the overall power it can produce. Combine that with the requirement of the engine to run extremely low ignition timing before seeing knock and you end up with a car that comes in pretty strong but doesn’t finish particularly well, the exact opposite of 2.0 Liter WRX’s in the past.

Our next set of tests is going to address one of the issues identified as we show the gains and benefits of converting to ethanol based fuels. Stay tuned!