This has been a long time coming but I’m happy to finally be able to post this up and help all my fellow 2015 WRX owners with making decisions on increasing the power of their cars. We took a methodical approach of adding 1 part at a time and doing a basic tune for each part so we could see the change each piece made. Thanks go out to OnPoint Dyno as always for providing us the dyno and tuning expertise. Before going further I want to make a note about how to look at dyno’s and understand things. With so many graphs floating around the internet it is very important to remember that every dyno is different and although I cannot speak for others it is imperative for us to show REAL results with no tampering. While in some cases this produces less then “jaw dropping” numbers it is reality and we prefer to be up front and honest. The first point I want to make is looking at peak numbers. It is important to look at this as a percentage change and not as just a number. A 100WHP change between 200WHP to 300WHP is a 50% increase in power but a 100whp change between 300-400whp is a 33% power increase. The second point is to look at the area under the curve and not just the highest point on the graph. Making a high number that only occurs for a small 100rpm area is not as useful as having a nice broad power band.
With that out of the way let’s get to the meat and potatoes of this post! We started off with a baseline for our 2015 WRX so we had a starting point to compare to moving forward. To say the least the results were a bit disappointing but from driving the car it was definitely lacking in the powerband department. It has a nice quick spool but the power is low and you can feel it. The only upside of this is at the track it gives you extra time to relax and less chance of getting yourself all out of shape with lots of power. We then installed the COBB AccessPORT and used their Off the shelf 93 Octane Stage 1 Map. As you will see this made a noticeable increase in power and torque pretty much everywhere with a really big increase in the lower end torque. The results ended up being about 6% increase in horsepower and 12% increase in torque over stock. Not bad for a simple reflash right? Side notes to this are that the OTS map made the car much smoother to drive. Power delivery was smoother, rev hang was gone and overall this is almost a necessary thing to do much like on the 05-09 Legacy GT that had the hesitation issue with stock mapping.
Event: Dyno
Location: Touge Tuning, Mississauga Ontario
Ambient Temp: Very Cold – February 2015
Elevation: 249 ft.
Weather: Cold
Car: 2015 Subaru WRX
Tuner: Sasha from OnPoint Dyno
Dyno Info: Dynapack
Transmission: Stock 6 speed
Gear: 4th
Stage 1 OTS Peak HP at RPM: 225 @ 5300RPM – SAE J1349 (2004) Corrected
Stage 1 OTS Peak Torque at RPM: 280 @ 3100RPM – SAE J1349 (2004) Corrected
Stock Peak HP at RPM: 212 @ 4900RPM – SAE J1349 (2004) Corrected
Stock Peak Torque at RPM: 250 @ 2500RPM – SAE J1349 (2004) Corrected
Baseline HP/TQ for Stock 2010 STi on same dyno: 228WHP/240WTQ
Target Boost: 19PSI Tapering
Fuel: 94 Octane Petro Canada
Mod List
-COBB AccessPORT – Stage 1 93 Octane OTS Map
This was great but we knew there was more on the table and so we had Sasha of OnPoint Dyno do a custom tune for the car. While it would be ideal to have done a full pro-tune for each mod we made the decision to have Sasha spend enough time to make the car safe without pushing the car to the ragged edge. Normally tuning takes 2+ hours but we spent about half that time which means there’s more smoothing to be done. After the pro-tune we were very very impressed by the numbers and it shows why a custom dyno tune is very much worthwhile for these cars! This took our percentage increase up to 15.5% horsepower and 14% torque. And just for reference we had a graph made showing the difference between Stage 1 OTS vs. Stage 1 Pro-Tuned.
Event: Dyno
Location: Touge Tuning, Mississauga Ontario
Ambient Temp: Very Cold – February 2015
Elevation: 249 ft.
Weather: Cold
Car: 2015 Subaru WRX
Tuner: Sasha from OnPoint Dyno
Dyno Info: Dynapack
Transmission: Stock 6 speed
Gear: 4th
Stage 1 Pro-Tune Peak HP at RPM: 245 @ 5250RPM – SAE J1349 (2004) Corrected
Stage 1 Pro-Tune Torque at RPM: 285 @ 3200RPM – SAE J1349 (2004) Corrected
Stock Peak HP at RPM: 212 @ 4900RPM – SAE J1349 (2004) Corrected
Stock Peak Torque at RPM: 250 @ 2500RPM – SAE J1349 (2004) Corrected
Baseline HP/TQ for Stock 2010 STi on same dyno: 228WHP/240WTQ
Target Boost: 19PSI Tapering
Fuel: 94 Octane Petro Canada
Mod List
-COBB AccessPORT – Stage 1 OnPoint Dyno Pro-Tune
Thanks to these companies that are helping with this Project
COBB Tuning – COBB AccessPORT and COBB Cat-Back
Mad Graphics – Full Vehicle Vinyl Wrap and Side Graphics
Grimmspeed – License Plate Relocation Kit
Turn In Concepts – Shifter Bearing and TGV Deletes
Killer B Motorsports – J-Pipe
OnPoint Dyno – Dyno Tuning and Testing
Uni-Body Collision – Paint Work (Emblems, Lip, Trunk Spoiler)
