Bucky Lasek’s “Subrina” STI Build

Bucky Lasek has been a customer of COBB Tuning for a number of years now.  A true gearhead at heart, he loves being behind the wheel and enjoys being able to blow off a bit of steam when necessary.  Being a driver for Subaru Rally Team USA, Subaru is obviously in his blood.  He recently paid our COBB Tuning SoCal shop a visit to bump up the power output of his 2012 STI.

Bucky’s goal with his 2012 STI was to show what the car is capable of with the budget of an average enthusiast in mind.  Simple is the name of the game here, every bolt-on part has a purpose.  The car is equipped with a coilover suspension kit, upgraded swaybars, and basic bolt-on performance pieces to increase airflow through the engine.  This is a car Bucky can take his kids to school in, enjoy a bit of spirited driving in the canyons outside of LA, or beat on at the road course.  He originally came in a few years ago to have the car custom tuned on the stock turbo utilizing the COBB Accessport.  The car made 321 hp and 364 ft/lb on a 50/50 blend of ACN91 and 100 octane fuel with an upgraded exhaust manifold, turboback exhaust, fuel pump, and intake.


Recently, Bucky approached us looking to step up the power of his STI.  The car already had great low-end torque, he was simply looking to add more mid and high-end power to back up that torque.  After a consultation with the crew at COBB Tuning SoCal, a short list of modifications was established to reach Bucky’s power goal.

All of that would be tied together with custom tuning on three fuel types – 91 octane, 91/100 octane blend, and E85.  With the convenience of the Accessport, Bucky is able to switch between these maps in no time at all depending on the fuel in the tank.

When all said and done, Jon Hebbeln of COBB Tuning SoCal was able to squeeze out 431 hp and 445 ft/lb with the new setup on E85 fuel.  For the every day driving on ACN91 fuel, the car is making 362 hp and 378 ft/lb and the 50/50 blend of 91/100 octane is putting out 385 hp and 406 ft/lb.  As you can see, with the addition of just a few parts, the car has really waken up.  The use of E85 allows a tuner to be much more aggressive with timing and boost.


Porsche Power : 997 Stock Turbo 60-130mph Record



The measurement of time it takes for a car to accelerate from 60mph to 130mph has become increasingly more popular over the past few years.  This method of measuring acceleration creates a real-world benchmark that can be exercised universally.

Recently, with the help of proTUNING Freaks and our Porsche Lead Calibrator, Mitch Mckee, Greyson was able to take his Porsche 997.1 Turbo from 60-130mph in just 5.9 seconds.  Mechanically, this car is equipped with an AWE exhaust, Porsche GT2 intercoolers, Injector Dynamics ID1000 fuel injectors, and upgraded turbo inlet pipes.  All of that is tied together with a custom tune by proTUNING Freaks on E85 fuel utilizing the COBB Accessport and Accesstuner software.

Below are the two V-box screen shots showing a 6.002 second and 5.978 second run.  The previous record for a stock turbo 997.2 was right at 6.4 seconds.

16374986520_99b1454450_o 16388234148_a5d0e7e247_b


For perspective, here is a list of 60-130mph times of some popular enthusiast vehicles (stock):

  • BMW E39 M5 – 14.3 sec
  • Mercedes E63 AMG – 10.93 sec.
  • Ferrari Enzo – 7.3 sec.
  • Mercedes SLR McLaren – 7.24 sec.
  • Porsche 997.2 Turbo (PDK) – 8.79 sec.

A more complete list of times can be found on ToTheFloor.com

Congratulations to Greyson and Protuning Freaks!!




2015 STI Development : Staged Power Package Evaluation

2015 Subaru STIAs you may know, one of our public commitments following the release of the new 2015 model year VA-series chassis code Subarus (2015+ WRX and STI) was to thoroughly explore each platform and quantify our findings whenever possible.  Because the 2015 STI retained a very similar mechanical configuration to the 2008-2014 STI (GR-series chassis code), many in the community have anticipated that hardware and tuning options would be identical to the current offerings.  The idea behind our testing was to discard any existing assumptions about how the 2015 STI may compare to its older brothers and make sure that we are providing hardware and tuning solutions that exceed expectations.

Two of the prevalent issues with the GR series WRX and STI have been a “Boost Creep” problem and a fuel system that is at or beyond capacity on cars that are equipped with a turboback exhaust, especially when combined with an upgraded free-flowing intake.  This topic was previously discussed here: Subaru Tuning : A Quick Look into Boost Creep.

The key item of significance here: Airflow increases must be met by increases in fuel flow – AFR is a ratio air against fuel, by definition, and thus they must increase proportionally with each other.  We’ve previously explored how adding an intake increases airflow on the 2015 STI in a previous article, available here: 2015 Subaru STI Development Update – COBB SF Intake Testing.

COBB Tuning's 2015 STI undergoing dyno testing a COBB Tuning Surgeline in Portland, OR
COBB Tuning’s 2015 STI undergoing dyno testing a COBB Tuning Surgeline in Portland, OR

Goal:  Analyze fuel system performance when attempting to tune for a COBB Turboback Exhaust and COBB SF Intake System on a 2015 STI.  Will the factory fuel system be adequate to support this setup?

Vehicle:  COBB Tuning R&D 2015 STI (#2).  ~900 miles on odometer.  92 octane pump gas.

Method:  In order to gather numerical data for analysis, we collected datalogs from the car under wide open throttle (WOT) dyno runs, in the following tune/hardware configurations:

  • Stock (S#); Stock
  • COBB v340 Stage1 93 OTS (S#); Stock
  • COBB v340 Stage2 93 OTS (S#); COBB Turboback Exhaust
  • COBB v340 Stage2+SF 93 OTS (Experimental) (S#); COBB Turboback Exhaust + COBB SF Intake System

Conditions:  45-48 degrees F, Sea Level elevation.  COBB Tuning Surgeline, Portland, OR.

Background:  In general, while performing aftermarket tuning, a fuel injector is considered to be at their flow limits once reaching ~95% Injector Duty Cycle (IDC).  Beyond this, the amount of “off” or non-driven time for the injectors between injection events is inadequate for allowing the electrical coil within the injectors to fully discharge.  With this, the beginning of the next injection event comes earlier than anticipated, as the injector is already partially charged when the ECU begins driving it for the next injection cycle, and the net result is a flow non-linearity (usually demonstrated as a brief rich dip in air-fuel ratio).  After passing roughly 105% IDC, even with this rich-leaning non-linearity, the total window for injection in terms of time is now simply too short, and an inadequate amount of fuel is delivered to maintained the desired air-fuel ratio, so air-fuel ratios begin to go lean of targets.

What does this mean?  Past ~95% IDC, we mechanically lose control over fueling and air-fuel ratio will not be on-target.  Dangerous lean conditions will result past ~105% IDC.

Things to keep in mind:  Air density is a critical factor.  We intentionally tested in Portland winter months, where temperatures are cool and atmospheric pressures are high.  At elevation and high ambient temps, the concerns mentioned above become reduced as air mass is reduced.  Keep in mind, however, that it was still in the mid 40’s during this testing.   Injector Duty Cycles could easily be 5-15% higher if the testing were completed in a much colder area around the United States, such as New England, which has seen a long period well below frozen this winter.

Results:  OK, time for the relevant stuff.  This chart shows the logged Injector Duty Cycle during a full-throttle dyno run for each of the aforementioned configurations.  We’ve added a red line showing the 95% threshold we would ideally like to stay below.

Graph of Injector Duty Cycle (Y-axis) against Engine Speed (X-axis) for each configuration
Graph of Injector Duty Cycle (Y-axis) against Engine Speed (X-axis) for each configuration

As we can see, the issue is already borderline on the completely stock vehicle.  Subaru targets an extremely rich air-fuel ratio and the 2015 STI has been observed to be the most powerful STI to date; one has to wonder why they have not upgraded the fuel system’s capacity to match this.

With tuning (Stage1), we see that peak values are similar to stock.  We are targeting a leaner AFR but using more boost/airflow to make more power, so overall total injector usage remains similar.

At Stage2, we’re really getting up there.  The fully upgraded post-turbo exhaust hardware facilitates more airflow and we use even more injector as a result.  No NASA scientists needed on this one!  However, while Injector Duty Cycle does definitively now exceed 95% for a good portion of the run, it stays around 100% peak.  We have lost control of fueling, but we probably are not going to induce lean conditions yet, meaning the engine should not be at any significant new risk.

Stage2+SF: Uh-oh!  Now that the intake side has been freed up, we’re using a LOT more injector.  With Injector Duty Cycles peaking around 107%, we can no longer be sure that there is enough fuel available to keep a ball-park safe air-fuel ratio, let alone precise control over it.

As mentioned earlier, this would only get worse as ambient temperatures go further downwards.  While mid-40’s is definitely cold for all of the Arizonians reading along, Michigan residents are likely nodding along in full agreement.  Much of the U.S. sees sustained temperatures well below 40 F during their colder periods of the year.

Summary:  So, where does this leave us?  In short, it means that we (COBB Tuning Subaru Experts) are not comfortable offering “Stage2+SF” as a released stage package for the 2015 STI.  We know this is likely to disappoint some and confuse others, especially since the package is still offered for the GR vehicles.   However, not all is lost.  Thanks to our partnership with Injector Dynamics, we are well-positioned to now offer OTS packages that include fueling system upgrades, which have typically been “custom tune only” territory for Subarus.  Be on the lookout for an upcoming COMPLETE Stage3 package for 2015 STI that includes fuel system solutions in addition to full turboback and intake hardware!

COBB R&D Update : February 2015

Here’s a quick peak at what our Engineering Team is working on for February!  Big projects include Ecoboost Mustang Turboback Exhaust, 2015 WRX Intake/Airbox Combo, and a COBB Exclusive – Accessport adjustable Traction Control!

Accesstuner Now Available for EcoBoost Mustang!


Accesstuner Pro is now available for the 2015 EcoBoost Mustang! Both AT and MT vehicles are supported. COBB Custom Features from other Ford platforms, additional custom tables, and all OEM tables, can be further tweaked by your Protuner! These include 5-Way Map Switching, Launch Control (MT Only), Burnout mode, and Flat Foot Shifting.



Accesstuner Race, the version of Accesstuner for individual use, is also available! With this software, you’ll be able to tweak your own OEM or Accessport Off The Shelf Maps. You can even open and compare the two to see all the changes that COBB has made.  Don’t trust a little black box that only jacks up timing and removes OEM safety logic!  See exactly what changes have been made, datalog and monitor several different parameters to ensure the car is happy, and even make changes yourself to support custom modifications!

Circut of The Americas : Wet Weather Testing

Being located in Texas has numerous perks, one of which is having Circuit of the Americas right in our backyard.  While this weekend’s forecast of rain would usually deter many avid track-day goers, we were excited as it would give the perfect opportunity to test some upcoming Accessport features.


Saturday morning we loaded up and headed down to COTA.  A dry morning lead into a very rainy afternoon.  Perfect.






Stay tuned, as we’ll be releasing more information in the coming weeks!



Accessport Updates: January 2015

In our quest for World Domination, we’ve pushed out two large updates for our Accessport product line.  The extremely versatile COBB Accesport now supports the 2015 Subaru WRX CVT and Porsche 996 Turbo/X50/GT2!

2015 WRX

Rounding out USDM Subaru DIT vehicle support, 2015 WRX CVT support is now LIVE for any SUB-004 Accessport!  All new orders shipped from cobbtuning.com will be ready to go out of the box, previously sold Accessports may require a firmware update using Accessport Manager.  All Subaru Accessports now feature our Auto On/Off feature!  This allows the Accessport to power on/off automatically with the vehicle!

Porsche_996TT_blog cover

Further expanding vehicle support in the Porsche market, we are excited to announce the availability of the POR-004 Accessport, supporting the Porsche 996 Turbo/X50/GT2!!  Initially, these Accessports are available only through COBB Authorized Dealers and Protuners.

Contact your preferred dealer now to place your order!!

Mustang Ecoboost – Intake and Intercooler Evaluation!

Our Ford Expert Group has been cranking away with the Ecoboost Mustang! In this video, Braden discusses what he’s been working on with Cold Air Intake and Front Mount Intercooler upgrades!

COBB R&D Update : January 2015

We’ve been hard at work on some new products and features due out in early 2015!

Here’s a quick peak at some of the exciting upcoming releases from the Subaru and Ford Expert Groups!!

2015 WRX Tuning Results : 344 WTQ / 313 WHP

2015 WRX_George_18_blog

We have enjoyed seeing all of the 2015 WRX custom tune results being posted around the ‘net and decided to jump in with our own after a bit of playing around with our car on the Austin R&D dyno today. While this combo of parts isn’t likely to be an pre-configured OTS “StageX” package that is available from us, we try to do as much hard parts testing as we can to make sure we have a good understanding of the cars. It’s important for us to have knowledge over how the car will react to common aftermarket upgrades. No records or anything crazy but this thing is definitely one quick WRX now!

We bolted up all of the airflow mods we have on-hand for the car and decided to see what she could do. A bit more time to continue refining the tune would have likely yielded even larger results, but I quickly “chickened out” after realizing how close we were to 350 wtq. :eek:  It is likely that the connecting rods will prove to be the long-term weak spot for modified FA20DIT cars, so we decided to call it an afternoon with our engine still intact for now :cool:

Engine/Power Modifications on our WRX consist of the following: COBB Tuning Accessport V3, COBB Tuning Turboback Exhaust (Catted), COBB Tuning SF Intake/Airbox (Prototype), TurnInConcepts TGV Delete Housings, Upgraded Aftermarket TMIC.

2015 WRX Dyno Chart

Results vs stock vehicle: +77 wtq (28.8%) , +62 whp (24.6%) 

At this point this car is now making a tad more torque and horsepower than a Stage2+Intake 2015 STI on the very same dyno — very impressive for a 2.0L with diminutive factory turbo. We are slowly beginning to really like these cars now as the uncorking process continues :)

Long term, this testing helped us identify some other areas of the factory ECU where we should focus our future reverse engineering (table/logic discovery) in order to provide the precise control and ease of tunability that the COBB Protuner network demands, even as the power numbers get crazier and crazier as new mods become available over time. We can’t wait to keep pushing this platform and seeing what kind of amazing results you guys achieve over time!

Thank you for your support during the DIT craze!


The COBB Subaru Expert Group