Subaru Tuning – A Quick Look into Boost Creep

11471414505_e75a453475_b

Boost creep is something we tend to address quite a bit during the winter months.  Below we will go over the causes of boost creep, why you should be aware of it, and solutions to keep your boost levels in check.

Boost creep is defined as a condition of rising boost levels past what the predetermined level has been set at.   For example, if your target boost level is 15psi, you would see the boost levels increase beyond that as RPMs increase.  The short explanation for boost creep is that the wastegate is not able to flow enough air to bypass the turbocharger’s turbine housing.  When the volume of air flowing through the turbine housing continues to increase, boost will also continue to increase.  Boost creep is most commonly observed in areas that have very low ambient temperatures as well as high atmospheric pressure.  This often encompasses those in the Pacific Northwest as well as New England and East Coast.

c6279971a5272432

Boost creep is undesirable for a number of reasons.  When a car exhibits a large amount of boost creep it makes controlling the boost level next to impossible for a tuner.  A car that is on the edge can exhibit highly variable boost response under different environmental conditions.  For instance, if you have your car tuned during warmer months, the change in weather going into winter may be enough to cause a significant increase in boost.  Once the flow limit of the wastegate has been reached, exhaust gas back pressure will increase.  This is very inefficient and will cause temperatures to increase and introduce more detonation-prone conditions.

Boost Creep is not a condition that can be corrected solely by making tuning changes as it is a mechanical limitation.  The two easiest ways to address boost creep are to either port the wastegate housing of the turbocharger in order to allow it to flow more air or to switch to an external wastegate style uppipe.

If you’re looking for answers to other tuning related questions, head over to our Knowledge Base!

COBB Releases BMW Stage 1+ Front Mount Intercooler and Stage 2 Downpipe with OTS Map Support

COBB is proud to announce the release of our BMW Front Mount Intercooler and N55 Downpipe along with off-the-shelf map support!

COBB BMW 1 & 3 Series N54-N55 FMIC Kit

COBB N54/N55 FMIC – One of the best power modifications for your BMW 1 or 3 Series – Click here for more pictures and details.

COBB BMW N55 Downpipe Kit

COBB BMW N55 Downpipe – Take your N55 powered BMW up to Stage 2! Click here for more pictures and details.

Tune your ECU for these modifications using our off-the-shelf maps!

 

2011 Subaru STI 12.4 sec. ¼ Mile using COBB OTS Maps!

10 years ago, Darius lined up his 2000 Ford Escort ZX2 with a shot of nitrous and some bolt-ons to pull a 14.37 at 96.9 MPH. Since then, he’s been hooked on drag racing with a variety of cars and recently ran a 12.42 at 109.4 MPH using only a 2011 Subaru STI Sedan with help from a COBB Downpipe, a COBB SF Intake and Airbox, and a COBB AccessPORT running off-the-shelf (OTS) Stage 2+SF mapping.

Time Slip

After setting the record for the fastest stock turbo, manual transmission diesel truck in his 2004 Chevy Silverado 2500HD Duramax Diesel, Darius decided a 2011 STI sedan was the perfect comprise of speed and comfort. He missed his old 2005 STi and couldn’t pass up a fast 4 door that featured Bluetooth, heated seats, and integrated iPod controls. To make his fast 4 door even faster, he opted for a few choice COBB parts. The AccessPORT with datalogging and preloaded maps for various modifications made tuning easy, the SF Intake added some power and sounded great, and the used COBB Downpipe mated up to the stock exhaust perfectly.

Engine Bay

With just $1200 spent on modifications and some excellent driving, Darius was able to run a 12.42 at 109.44 MPH with a 1.686 60′ time. And to prove it was no fluke, he followed it up with a 12.44. Next season, Darius hopes a few more modifications, some custom tuning, and experimentation with the Launch Control and Flat Foot Shifting features built-in to the AccessPORT will get him down to the 11 second range.

If you’d like to learn more about the AccessPORT, the COBB SF Intake, the COBB Downpipe, or any of our other products, just visit www.COBBtuning.com.

Darius STI

COBB Tuning 08+ Nissan GT-R Downpipes Available Now!

COBB Tuning introduces the 3” Stainless Steel Downpipe Kit for 2008+ Nissan GT-R vehicles. These stainless steel units are the same downpipes that helped power our COBB Motorsports Redline Time Attack Modified Class GT-R to a Class Championship in 2010! Designed to bolt up to the stock turbos or stock-location upgraded turbocharger kit, this downpipe kit has been rigorously track-tested and proven reliable at power levels beyond 800whp.

Take your Stage2 GT-R with upgraded Y-Pipes to the next level with the COBB Tuning 3” Downpipe Kit. Consistently improve turbo spool-up by 250-300RPM and open the door to maximum stock turbo power output when coupled with complementary modifications including; injectors, fuel pumps, intakes, boost tubes and intercoolers.

These high-flow, mandrel-bent, 304-stainless downpipes remove the restrictive stock catalytic converters for better flow, faster turbo-spool and improved transient response. This downpipe kit is a direct OEM replacement and will bolt up to the stock exhausts system or aftermarket systems alike.

For more information on the COBB Tuning 3” SS Downpipe Kit for the 08+ Nissan GT-R, please visit our website at www.cobbtuning.com or call toll free at 1-866-922-3059.

COBB Tuning Dominates Redline Time Attack Round 4 at Auto Club Speedway

The COBB Tuning Motorsports team dominated Round 4 of the Redline Time Attack series at Auto Club Speedway in Fontana, California, taking 1st in Super Modified AWD, 1st in Modified AWD, 1st in Street Tire AWD and capturing the Overall Event Win. The Super Session wheel-to-wheel race was an exciting inter-class battle and saw the Nissan GT-R win overall in Modified trim and the STI take the Street Tire class win. In addition to bringing home maximum points, Brian Lock set a new track record for a Modified Class car at Auto Club Speedway in the GT-R with a lap time of 1:43.072.

In a bid to appease the “Racing Gods,” the team showed up sporting COBB-blue hair-dos, but the success of the weekend was a direct result of the long hours and tireless effort put in by the talented and dedicated guys that make up the COBB Tuning Motorsports crew. The team took advantage of the month-long break between events and made significant changes to all three race cars in an effort to maximize performance and reliability, ultimately setting the team up to race hard for the remainder of the season.

The Nissan GT-R was treated to a complete engine rebuild with upgraded rods and pistons to better cope with the nearly 1,000 crank HP being produced. The Subaru STI went under the knife having a new custom safety cage fabricated from scratch and the transmission rebuilt while the Cosworth engine was sent home for a refresh and new Cosworth intake manifold added. The Nissan 370Z received a new set of rear springs to reduce excessive corner-exit oversteer. Finally, all three cars had OS Giken limited-slip differentials installed (GT-R front, STI & 370Z rear) to better get the AccessPORT tuned power down on the track where it belongs.

The extensive hours of hard-work paid off in spades as the team racked up its most successful weekend to date in the Redline Time Attack. Brian Lock in the Nissan GT-R screamed past the competition to take the Modified Class win and set a new track record of 1:43.072 in the process. After setting the new record, the GT-R visited pit lane to receive a new set of Yokohama A005 racing slicks before heading right back out on track to battle it out in the Super Modified class. The added grip of the Yokohama slicks dropped the GT-R’s lap time to a 1:39.730, fast enough to take the win in the Super Modified class and clinch the team’s second Overall event win!


photo courtesy of rpmgear.com

In the Street Tire AWD Class, Cameron Benner was on a mission to grab the 1st place position that had so far eluded him. The revitalized Subaru STI proved to be the perfect tool for the job as Cameron charged ahead the rest of the Street Class field, taking a decisive first win with a 3-second lead over his closest competitor!


photo courtesy of rpmgear.com

Gary Sheehan subbed in for an ill-feeling Trey Cobb to take on the Nissan 370Z driving duties. Although Gary was ineligible to compete in the Enthusiast Class, the event presented an opportunity to see how the suspension and driveline changes affected the performance of the little Z, and they proved to be quite effective. The COBB 370Z turned a time just 0.5 seconds shy of the Enthusiast RWD class winning lap in the final Time Attack session, and also revealed a few simple areas of improvement that, once addressed, should make it a serious class contender.


photo courtesy of rpmgear.com

The wheel-to-wheel Super Session turned out to be an exciting inter-class battle that once again showed that solid preparation, nerves of steel and blue hair will take the day. Brian Lock ran the Nissan GT-R in Modified trim with R-compound tires and gapped the field to take the overall win and much-needed Modified class championship points. Cameron Benner had a great drive in his Street Tire Class STI, battling with Modified class cars on the way to his class win and 4th place overall, adding to his impressive championship lead.

The Takata Time Attack/LIC Motorsports STI, had a strong showing this weekend, taking 2nd place in the Modified AWD Class with a 01:45.923 lap time and 2nd place in class in the Super Session . This car runs a COBB AccessPORT and was tuned at COBB Tuning Surgeline in Portland, Oregon. The LIC Motorsports team continues to show what quality preparation and great tuning can do as they consistently field the fastest Modified Class Subaru in the series and currently lead the Modified Class championship.

Jon Drenas showed what a lightly modified Mitsubishi EVO X can do by finishing in 2nd place in the AWD Street Class. Jon arrived at the track late in the event and laid down a 1:52.702 lap with almost no practice time in his HB Speed-tuned AccessPORT EVO X. Jon and his EVO X is a force to be reckoned with on the West Coast and has proven that you can drive your race car to the track, race it all weekend, and drive back home with a trophy in the passenger seat.

Chris Billedo drove his AccessPORT equipped Honda Civic Si to the sharp end of the Enthusiast FWD class with a solid 2nd place finish, continuing his streak of podium finishes and setting himself up for an impressive Redline Time Attack championship result.

The COBB Tuning Motorsports Team next heads to Autobahn Country Club in Joliet, Illinois for Round 5 on June 12th where they look to extend their East Coast Championship leads in the Modified and Street Tire classes.

 

  [nggallery id=17]

The Battle of the Bayou, Two Lousiana EVO X’s duke it out at COBB Tuning Plano

Two EVO X GSR’s, Two friends, Similar setups, different sets of cams, different downpipes, 875 combined wheel horsepower, one tuning shop.

In February, COBB Tuning Plano tuned James Stearns’ EVO X GSR running a Forced Performance “Red” turbocharger, it made good power gains over the stock turbo, but we knew the car had so much more potential. A set of good camshafts would be needed to make the car work with the bigger turbo more efficiently. A set of Kelford 214b cams were ordered knowing that they would do just the trick!

Not to be outdone by his good friend, James, Dustin Nelson decided to step it up and purchase a FP Red for his EVO X as well. Duston also upgraded to the COBB SS Downpipe and decided on the Cosworth MX-1 camshafts.

Both agreed to come drive up from the Bayou of southern Louisiana and drop off their cars for a few days, anticipating some very impressive gains. James started with 377whp and 361ft-lbs of torque, while Dustin’s car weighed-in with 331whp 378ft/lbs. After the installations, James was first up on the dyno and netted a gain of 57whp and 34 ft/lbs making this car the most powerful EVO X at COBB’s facilities in Plano at 434WHP and 395WTQ at 27psi on 93 octane gasoline!

That record would be short lived though, as 26 hours later, COBB Tuning Plano’s lead tuner, Calvin Dotson, made 441WHP and 393WTQ on the same boost pressure of 27 psi and on 93 octane out of Dustin’s Octane Blue Pearl EVO. This set a new bar of power achievement on any EVO X in COBB’s dyno database and netted 110whp over his previous setup!

Congratulations to these two guys, we bet the drive back home was incredible!

Brian Lock: Redline Round 2 – New Jersey Race Recap

Brian Lock Stands Next to GT-RJust when I thought COBB Motorsports was cursed with the worst bad luck on the planet (I could write a book on missed deadlines from vendors over the past two months), it got worse. The most random, confusing, undiagnosable limp mode was rearing its ugly head all day Sunday at the track. After pulling all-nighters, driving all around California to find a new motor for the GT-R, and just busting butt all week to get the GT-R repaired after the failure at Buttonwillow, to have the car possibly not finish the New Jersey event was almost more than I could bare. I saw the long faces in the paddock showing the disappointment in the prospect that we might not finish.

Through all of that though I was so impressed that the crew never stopped thinking. Yes we were “throwing mud at the wall”, but we were not going to stop until the GT-R could finish a lap! And somehow, at the very last moment, it did. I could see the excitement and relief of the crew as I rolled in from the last time attack session. We had won, but I don’t think I can handle the blood pressure for any more wins like that!

Other than the electrical system throwing us a nasty curve ball, the rest of the GT-R was performing perfectly. The OS Giken rear diff is showing no signs of wear according to the data acquisition and it is consistently letting the car launch off the corners hard.  Our PFC brake rotors from MBS are still going strong from last year at Auto Club Speedway. A minor adjustment to our new APR GT-500 wing got the aero balance right where it needed to be for New Jersey.

A big thanks to Brian Hise from JRZ this weekend. He made the trek out to NJMP and worked his magic on the GT-R chassis. Since OS Giken does not have an application for the front diff of the GT-R yet (hint, hint) we had to tweak the chassis to help control front wheel spin. The car setup is getting better and better and the car is becoming more  of a joy to drive.

Looking ahead to Las Vegas in a little more than a week, even with a much stronger field anticipated, I am confident our GT-R has what it takes to make it three for three. It’s been a great start to the season so far and we want to keep this momentum going!

[nggallery id=12]

COBB Motorsports Wins Big in New Jersey

COBB Tuning

COBB Motorsports’ 3,000 mile trek from California to New Jersey paid off big with Brian Lock taking the the Overall Win in his Nissan GT-R Modified Class car, a historic first for the Redline Time Attack series. Cameron Benner and his Street Tire Subaru STI were strong all weekend and brought home the 2nd place trophy in class. Trey Cobb and his Enthusiast Class Nissan 370Z are beginning to hit their stride and finished a strong 4th in class. With equally impressive performances in the Super Session wheel-to-wheel race, COBB Motorsports left New Jersey leading the East Coast Championship points race in both the Modified AWD and Street Tire AWD classes and 4th place in Enthusiast RWD Class.

Brian Lock

Success did not come easily, as the weekend certainly had its challenges. The Modified Class Nissan GT-R began developing engine hiccups in right hand corners early in the weekend that became progressively worse throughout the event. Sr. Calibrator Tim Bailey and Car Chief Dustin Harris initially suspected fuel starvation issues, but problems continued even with a full fuel tank, triggering the ECU into limp mode and forcing Brian to pit. The issue was later determined to be electrical, which can often be very difficult to find and solve quickly. The GT-R failed to complete a single full power lap in both Sunday morning practice sessions and even took the car out of the first timed session on Sunday afternoon. The team worked feverishly between Time Attack sessions, checking every electrical connection and thoroughly securing the wiring loom to prevent any movement on track. The scramble paid off in spades and Brian was able to get the GT-R to perform at its peak, delivering three flying laps in the final Time Attack session, producing a staggering laptime of 1:06.768. This turned out to be the fastest lap of the event, giving the Modified Class AWD win, Modified Class Overall win and Event Overall win to a Modified class car for the first time in the history of Redline Time Attack.

Cameron Benner

Further complications arose mid-event with the Subaru.  Cameron Benner’s weekend started out very strong with the Street Tire Subaru STI nipping at the heels of cars in the higher performance Modified Class. Cameron came in to Round 2 still on a steep learning curve with the Redline Time Attack format and his limited experience learning new tracks, but his lap times and composure on track certainly didn’t show it. Trouble started late in the day on Saturday with an external wastegate fitting failure which caused boost control issues. Car Chief Brian Marstellar was able to re-tap the wastegate with a larger fitting, however, damage to the wastegate was ultimately more severe than initially thought, resulting in boost levels that were 5psi lower than the targeted 24psi and really hurting power production. Tim Bailey worked some more of his AccessPORT tuning magic to coax some additional boost and power out of the STI boxer, giving Cameron just enough back to secure a strong 2nd place podium in Street Tire AWD in final Time Attack session of the day.

Trey CobbTrey Cobb Nissan 370Z

Trey Cobb’s Nissan 370Z proved to be trouble free throughout the weekend, giving him a stable platform to further develop his driving talent. Billy Brooks, Cobb Tuning’s lead Hard Parts Engineer, tweaked the 370Z’s suspension between events, and Brian Hanchey of AST Suspension helped the team dial-in the 5200 series double adjustable coilovers at the track, which helped resolve the corner exit power-down problems Trey was experiencing at Buttonwillow. Trey quickly got down to business of learning yet another new track and pushing the performance envelope of his 370Z while never putting a wheel wrong throughout all the practices. In the final Time Attack session Trey put his head down and got to business pushing the mildly modified Z to the limit, and beyond. Trey was able to put together a fastest laptime of 1:21.672, just 9/10ths of a second out of a podium position in Enthusiast RWD class and 1.5 seconds faster than the nearest Enthusiast AWD turbo EVO Xs!

The crowd favorite Super Session wheel-to-wheel race once again provided plenty of action. Brian and the Modified GT-R sat on pole with Cameron in the Street Tire STI took the green flag from the back of the grid. Brian had a great battle with the Turn In Concepts WRX driven by Tony Wiesenhahn and ultimately prevailed, taking home the Super Session overall win and firmly putting him in first place in the Modified East Coast Championship. Cameron took home the win in the Super Session Street Tire class, and the extra points pushed him into the Street Tire East Coast Championship lead as well.

The COBB Motorsports team is back on the road again heading west for the next round of the Redline Time Attack at Las Vegas Motor Speedway. The rig will stop off in Salt Lake City, UT so the cars can be treated to a much needed round of service and some additional track testing at Miller Motorsports Park before picking up where it left off in the West Coast Championship points scuffle. Brian and the Nissan GT-R sit 2nd in points in the Modified West Coast Championship, Cameron and the Subaru STI are currently leading the Street Tire West Coast Championship and Trey and the 370Z are sitting in 7th in the Enthusiast Class West Coast Championship.

Everyone at COBB Motorsports is fired up from overcoming the obstacles thrown at them in New Jersey and are looking forward to bringing that success back into the West Coast Championship. Come on out to Las Vegas Motor Speedway on April 23-25 to see all the Redline Time Attack action and be sure to stop by the COBB Motorsports rig to hang out with the crew and check out the racing hardware. See you there!

[nggallery id=10]

AccessPORT Racer Spotlight: HBSpeed EVOX Jon Drenas


The season opener of the Redline Time Attack series, held at Buttonwillow Raceway Park, kicked off to a very eventful weekend! With a test and tune session held on Friday, practice sessions held all day Saturday, and two rounds of practice on Sunday, crews had their hands busy making adjustments to their vehicles to make the quickest times. HB Speed’s Jon Drenas and Danny Heng were still unsure if the team would compete as the 2008 Mitsubishi Evolution X was still strapped onto the dyno finishing up a tune on Thursday night! With the help of their COBB Tuning Accessport, the team  squeezed every little bit of additional power from their Forced Performance “Red” turbo-charger, a tubular exhaust manifold from CBRD Speed Factory and new Deatschwerks 1500cc injectors! Wrapping the tune up that night, the decision was made to run in the season opener early Friday morning via text message.

The team was forced to make significant changes to their suspension setup due to the new minimum ride height rules. To further complicate matters, the splitter shed some parts on the drive up from LA to the track. Jon was able to fabricate new mounting hardware at the COBB Motorsports trailer, track side! Jon also discovered that their cat-pipe had fouled during practice. Once again, a quick track side fix enabled them in install a replacement, but smaller, catalytic converter and get the car back out on track.

Knowing that there was a significant power loss from the modified cat pipe, Jon went for it. The first lap came in at 1.58:1, leading in to a very competitive race against the clock. Jon decided the new ride height could easily handle a little dirt/rally action during the third lap while passing COBB Tuning’s Cameron Benner, and despite kicking up a dust cloud and having his teammates skip a few heart beats, pulled away from the cloud and still managed to bring in a lap time of 1.59:8! Exciting racing, capped off by an exciting weekend! HB Speed and Jon secured the lap time of 1.58:1 and used that to finish in 2nd place in the Street Tire AWD class! Proving once again that AccessPORT-tuned vehicles are motorsports-grade. Steven Ruiz, driver of the StopTech Mitsubishi Evo X placed 1st with a time of 1.57:5 and Cameron Benner, driver of the Cobb Tuning Motorsports Subaru STi placed 3rd with a time of 1.58:9.

COBB Tuning EVOX Downpipe and Testpipe back in stock!

Back by popular demand! The COBB Tuning EVO X Exhaust components are once again available from All COBB Tuning retail stores including COBB Tuning Surgeline, COBB Tuning Plano and COBB Tuning.com!

EVOX Test Pipe with High-Flow Cat

The COBB Tuning Mitsubishi EVO X “Test Pipe” features a high-flow catalytic converter and is a direct bolt-in replacement for the restrictive factory unit. Made of 304 stainless steel with a 3″ diameter, COBB’s Test Pipe will work with the OEM exhaust, as well as any exhaust that is designed to keep the factory catalytic converter.

EVOX Downpipe

The COBB Tuning Mitsubishi EVO X Downpipe features a widened diameter of 3″ for increased flow of exhaust gases from the turbo charger to allow for improved horsepower and torque. The downpipe is constructed of 304 stainless steel, mandrel bent tubing, which can be fitted to the OEM exhaust or the COBB Tuning EVO X Test Pipe.

Application Price
EVOX Test Pipe w/HFC $295
EVOX Downpipe $245