2015+ WRX Parts Recommendations

Quicklist

• Cobb AccessPort and Cobb Flex Fuel
• Cobb Fuel Pressure Sensor Kit (part # 315650 )
• IAG Street Air Oil Separator (AOS)(stock turbo), Comp AOS or Radium catch cans for upgraded turbo cars
• PRL or ETS FMIC (4 inch core) 
• Grimmspeed Catted Turbo Back Exhaust (TBE), GS Electronic Boost Control Solenoid (EBCS), GS Top Mount InterCooler (thermal coating)
• Dw300c fuel pump ( 9-307-1010 install with white stock spacer + 2 o-rings  )
• Cobb LF ByPass Valve (BPV)
• Grimmspeed Intake / CobbSF Intake
• Killer B Header w/ Swaintech Coating
• Motec + Port Injection
• AEM Meth Injection v3 (VP M5 Methanol, 500cc Nozzle)(Part # 30-3300)
• ACT Extreme Street (SB11-XTSS) = 410 wheel tq capacity
• Competition Clutch MPC Twin Disk (4M-15021-1)= 750 wheel tq capacity

** I do NOT recommend a catless exhaust unless you get an external wastegates  Without the ext wg's you chance overboosting via boost creep, which causes the car to run out of fuel, lean out, and ultimately knock knock boom. 

Power Estimates

** Remember that these are just estimates.  Each car is different.  Every car experiences what's known in the engineering world as tolerance stacking.  Each component on the vehicle is allowed to be within a certain tolerance.  IE the pistons are allowed to be between a and b, the compressor wheel on the turbo is allowed to be between c and d, the turbine wheel between e and f, the rods between g and h, etc etc etc for every component on the car.   Some cars will end up with a combination of all favorable tolerances, some will end up with average, some will end up will all poor, and a few will end up with the golden combo.  Also remember that things like wheels and tires play a big role.  They are rotating mass.  So if you are stage 2 and slap on some heavy 18 inch wheels and tires, your care will likely make less power than what's listed here.  **

- Stock  Baseline - 230-250 tq,  220-240whp depending on DAM, FLKC, etc

- Cobb Stage1 91oct OTS Map - 240-250tq, 230-240hp

- PhatBotti Stage1 Tune  260-270tq, 240-250hp

- EBCS w/ Tune 265-275 tq 250-260hp

- Jpipe EBCS w/ Tune 275-285 tq 255-265hp

- GS/PW TMIC J Pipe EBCS w/ Tune 295-305tq 265-275hp

- GS/PW TMIC J Pipe EBCS KB Header w/ Tune 305-315tq 275-285hp

- GS/PW TMIC J Pipe EBCS KB EXT WG Header w/ Tune 310-320tq 285-295hp

- GS/PW TMIC J Pipe EBCS w/ Flex Fuel Tune 350tq 355-365hp

- PRLFMIC J Pipe EBCS KB HDR EXT WG w/ Flex Fuel Tune 350tq 400hp (aggressive map, you may meet Rod)

An easy way to guesstimate power potential based on turbo airflow is to add a 0 to the lb/min flow rate, that's the max crank hp the turbo can make based on how much air the turbo can flow.

Then if you want whp multiply by 0.8.  That's the ballpark each can make.        

REMEMBER THESE ARE BALLPARK GUESSTIMATES. 

stock turbo =  380-400 whp 

SoCal v3      =   430-450 whp (depending on fuel mods)

FP Blue        =   440-540 whp (depending on fuel mods)

Q:  I just got a 2015+ WRX, what is the best/cheapest/easiest way to make power?

A:  ETHANOL, ETHANOL, ETHANOL.  A stock car on an e30 tune will make more power (320whp) than a full bolt on pump gas car (300whp).   A stock car with Cobb Flex Fuel and dw300c can make 330-350whp.  Once you are able to run ethanol the parts matter way less.  These cars love ethanol since they are high compression, that's why they pick up so much more hp than an EJ does on e85.  An EJ with pick up 30-40whp on e85, an FA will pick up 80-100whp on e60. 

THE WHOLE POINT OF A FLEX FUEL KIT AND FLEX FUEL TUNE IS THAT ONCE THE TUNE IS COMPLETE YOU CAN RUN PUMP GAS OR ETHANOL ON ONE MAP.  THIS DOES NOT INCLUDE BEING ABLE TO SWITCH BETWEEN 93 oct and 91 oct.  IF YOU MAINLY RUN 93 Oct PUMP GAS BUT NEED TO RUN 91 Oct ON ROAD TRIPS YOU WILL NEED A SEPARATE MAP.  IF YOU RUN 91 Oct ON A 93 TUNE THE CAR WILL KNOCK HORRENDOUSLY AND POTENTIALLY BOOM BOOM THE ENGINE (DESPITE THE OWNERS MANUAL CLAIMING IT WILL NOT CAUSE ENGINE DAMAGE). 

The one downside to ethanol is that the stock high pressure fuel pump on certain cars does not like ethanol levels over e70.  Some cars even have issues at e60, but this is pretty rare.  So if you are running the stock hpfp you will need to mix down to e60 (basically 12 gallons of e85, rest pump gas).  You can run full e85 if you get a nostrum hpfp.  That is gone into more detail towards the bottom if this page https://phatbottituning.com/mod-path

RUNNING ETHANOL WITHOUT A FLEX FUEL SENSOR

Some people choose to run e60 without the flex fuel kit, all you need is the AEM340 or DW300c fuel pump.  So for $110-170 your car can pick up 100whp over pump gas.  However, I DO NOT RECOMMEND DOING THIS unless you are intimately familiar with ethanol and how the content changes at the pump in your specific city/state.  If you are tuned on  e60 when the pump was spitting out e85, then the gas stations switch to e52 in the winter and you don't compensate for it, you will be way down on ethanol/octane and likely experience engine failure.  12 gallons of e85 and 4 gallons of e10 pump gas results in a final ethanol content of e66.  Where as 12 gallons of e52 and 4 gallons of pump gas results in a final content of e40.  This drop in ethanol content will significantly change the knock resistance, the AF Correction/Learning, and the overall drivability of the car.  Shops in areas where the ethanol content varies in the winter have reported contents as low as e30 at some pumps...which would ensure engine failure.  It simply isn't worth risking a $5,000-8,000 engine over a $600 flex fuel sensor.  Do it once, do it correctly. 

If ethanol is not available in your area, then methanol injection is the next best solution to making power on these cars.  Methanol injection has the added benefits of increasing the octane, decreasing the intake manifold temperatures, and cleaning the valves.  Increasing the octane and decreasing the intake manifold temperatures will both move you further away from the knock threshold and thus make the car safer while allowing you to make more power.  So if you're going to eventually spend $400 on a walnut blast to clean the valves, you might as well spend $470 on an AEM Meth kit and receive the added benefits.

I recommend the AEM v2 meth kit spraying pure VP m5 methanol with the medium nozzle (500cc).  Pure methanol is better than 50/50 water meth.  Our goal is to add fuel.  Pure VPM5 will drop the charge temps significantly and will make 15-25 hp more than M1 or M3.  If you have to run a 50/50 water meth mixture, then run the largest nozzle (1000cc).  Set the controller to start spraying at 10psi and be spraying full at 14 psi.  For a TMIC the nozzle is installed in the intercooler outlet tank (reference GS TMIC as it has a port included).  For a FMIC the nozzle is installed in the intercooler pipe 6-8 inches before the throttle body.   

* I do not like the Snow Performance kits and they are not compatible with pure meth

* AEM v2 nozzles are compatible  with pure vpm5

* AEM v3 nozzles are NOT compatible with 100% methanol.  A 50/50 water/meth mix must be used

* I do NOT recommend using Snow Performance Boost Juice or Devils Own Brew.  You can go on YouTube and watch multiple videos of customers testing these products for methanol content and getting values as low as 10% methanol when it's supposed to be 50%.  If you need to run a 50/50 mix, then I would highly suggest sourcing pure methanol from VP and making your own 50/50 water/meth mixture.  This will ensure you truly have 50% methanol.  

* My nozzle size recommendations are for cars with stock turbos, SoCal v3 or FP Blue turbos.  The more power you are trying to make, the more fuel you will need.  If you run a 50/50 mix, then your power may potentially be limited by fueling needs.

AEM Meth Kit Part # 30-3300  (full meth kit w/ controller and 1 gallon tank)

AEM Meth Solenoid 30-3326 (required - install close to nozzle to prevent siphoning into manifold)

AEM Filter Part# 30-3003 (required - keeps nozzle from getting clogged)

ProMeth 100% Methanol Compatible Nozzles are here - https://prometh.com/collections/nozzles/products/8-0-gph-63-cc-per-minute-water-methanol-injection-nozzle?variant=18900548911173

Pure vpm1 or vpm5 then use 500cc nozzle (* AEM v3 nozzles must use a 50/50 water/meth blend)

50/50 water meth then use 1000cc nozzle

TMIC Nozzle - install nozzle in intercooler outlet endtank (ref GrimmSpeed TMIC for location)

FMIC Nozzle - install nozzle in intercooler pipe 6-8 inches from throttle body

Start Spray - 10 psi

Full Spray - 14 psi

How to wire up a failsafe relay   https://youtu.be/G6ywmIzRexE

Fueling

Once you reach the full bolt on mod level and beyond and start pushing things these cars are on the verge of running out of fuel at high rpm.  When they run out of fuel they get very angry very fast.  When an STi or old WRX run out of fuel they will simply start leaning out and may eventually knock.  The FA's however see an immediate adverse reaction when the fuel limitation is reached.  This can result in misfires and or knock which can ultimately lead to engine failure in a single pull.  This is also the main reason I don't tune catless cars because it is exactly what happens when cars boost creep at high rpm, the boost rises and the cars run out of fuel. 

These are some options to add fuel to the car

1 - Motec + port injection:  basically $13,000 - $15,000 and is the only proper solution to the fueling issues.   The Motec can control the direct and port injectors correctly.  Even though this is very expensive and out of most people's budget, it is the only proper way to add extra fuel to the car.  Anything else is a lesser solution and has multiple downfalls.   

2 - Port injection + Split Second Controller: $6000 this option is also very expensive and has multiple downfalls.  The split second controller is an auxilliary device and does not talk to the ECU.  One of the main issues with this solution is that you are paying a premium to install expensive fuel injectors on the car to atomize the fuel.  But the split second controller only batch fires the injectors.  This means that all 4 injectors are spraying all the time in a "batch".  So even when cylinders are on the wrong stroke those injectors are still spraying on top of the closed intake valve.  So all that money you just paid to atomize the fuel is going to waste puddling fuel on top of the valve.    Another downside to the split second controller is that it requires it's own software and logging cable, which means for e-tuning the customer would need to have a laptop to be able log the port injection data.  The split second software also does not allow you to modify the data for a car unless you are hooked to the car, which would require lots of time and coordination to log into each customers computer to make changes for each pull.  And overall it's simply better to have large setups like this done in person due to all the money involved.  Due to all of these issues I will not e-tune port injection cars.

3 - Meth injection (pre-throttle):  $500 - $1500 this is the cheapest solution.  There are many different brands and variations of methanol injection kits with all different levels of failsafes and bells and whistles.  I will not be going into those here.  Meth injection has multiple downfalls.  It is an auxilliary system just like the port injection and it doesn't talk to the ECU.  While failsafes can be added, they are still not as good as everything being in a factory ECU or one unit like the Motec.  Another issue is the meth distribution to each cylinder.  We have no way of knowing how much meth is making it to each cylinder.  At first the boxer design may seem like it's really bad for meth injection, but if you look at if compared to an inline 6 cylinder where the meth would be siphoned off to 5 cylinders before getting to the 6th, our center entrance throttle body and split manifold is actually no where near as bad in comparison.  I do not recommend port meth as it can cause issues running extremely rich after throttle lift because port meth is batch fired just like the port injectors.  I was recently made aware of this port meth kit and controller that can pulse the meth nozzles based on rpm and firing order (at least i think, only briefly looked into it).  Obviously haven't had a chance to test it yet, but looks very promising.   https://torqbyte.com/collections/products/products/cm5-lts-water-methanol-injection-controller 

The Cobb AP is needed to be able to tune the car.  It is the electronic device that allows you to flash a tune to the ECU, change maps, adjust launch control, adjust flat foot shifting, monitor 6 gauges, and see check engine lights.

No, I do not tune EcuTek.

Flex fuel is the easiest and cheapest way to make power on these cars.  The car will easily pick up 60whp going from 91 octane to an e50 blend.  The stock fuel pump is not ethanol compatible and will eventually fail, so it needs to be replaced with a DW300c unit.  The DW300c should be installed utilizing the stock spacer and 2 o-rings. 

Flex fuel allows you to run anything from pump gas to e60 on 1 map, no map switching required.  There are 2 sets of tables in the ECU, low ethanol content tables and high ethanol content tables.  The car will be tuned on "low ethanol" pump gas which is usually 10% ethanol, then it will be tuned on "high ethanol" e60 (or full e85 if you have the Nostrum or IBR HPFP).  You can picture the low and high as the bookends of the tune.  Once the tune is complete, it will basically "slide" between these 2 endpoints based on the ethanol content.   

Yes, the AEM340 pump is also fine.  The LPFP is required for flex fuel.

I do not recommend using the Penguin Tech flex fuel kit.  I worked with 1 customer with their kit and it had to be replaced twice in 2 weeks.  Seems like too high of a failure rate for me to work with.  I have dealt with over 1,000 Cobb kits and only seen 10-15 failures which is less than a 1% failure rate.  I simply can't get on the dyno to tune a car and have the parts be in question.

CATLESS EXHAUSTS & EXTERNAL WASTEGATE INFO

CATTED J-PIPE - Ultimately just selling the catless j-pipe and picking up a catted one is my most favorable solution, but it is both costly and time consuming so I know most people will not do it. 

METH INJECTION - This is the simplest and cheapest solution I can recommend.  I will tune a catless car if a methanol injection kit is added.  Since the issue with being catless is running out of fuel, adding meth will increase the fueling capacity of the vehicle and prevent you from running out of fuel if a boost creep situation does occur.  Meth injection also has the added benefits of increasing the octane of your fuel, decreasing the post intercooler air temperature entering the engine, both of which will reduce knock and it will also clean the intake valves so you won't have to walnut blast them later.  So if you're going to spend $400 to have someone walnut blast the valves at some point, then it seems like a no-brainer to spend $470 on a meth kit now and receive all the added benefits from it.

EXTERNAL WASTEGATE HEADER - I do not really recommend this since they are expensive for the gains and benefits.  You can literally buy an FP Blue + meth injection for the same price and make 60-80 more hp.   The ext wg option is going to set you back $2000+ and likely defeats the reason you went catless in the first place, which was to save money.  The boost control is not greatly enhanced with the ext wg's and (generally speaking) most people need to run lower wastegate springs to prevent overboosting, boost creep or really sensitive boost control.  On an EJ if you put a 14 psi wg spring in, the car will run 14 psi flat with the boost control zero'd out.  On an FA, with 14 psi springs in cold weather and the boost control zero'd out, they can run 24 psi.  I would really only recommend ext wg if you just want the noise.  Personally I would put the money towards a short block fund or an FP Blue.

External Wastegate Summary:

-  Do the ext wg have benefits?  Yes, they can reduce back pressure and add power.  Maybe 10-20 hp on a maxed out car, but this is mostly dependent on the turbo IMO.   On a send it map, the tuner is trying to run as much boost as possible (IE, holding the wastegates closed).  So you will just end up spending $2000+ on the ext wg just to have them held shut at high power levels (this is why they get quieter as the power (boost) is turned up.  

-  For $2000 you can literally by an FP Blue and meth injection and make 60-80 whp more for the same price.  Is 80 hp more safe on the stock block?  No.  If you are stock block you can put the $2000 towards a built shortblock instead.  

- 8 psi spring in each wg (black spring)

- do NOT wrap your headers

In ranking of keeping contaminants out of the engine

1 - Radium catch cans

2 - IAG race/comp

3 - IAG street

I usually recommend the Street for daily driven vehicles simply because it is a maintenance free item.  But from a performance standpoint of keeping oil and fuel vapors out of the engine, catch cans are ultimately the best solution. 

If you are running an upgraded turbo, then the comp/race setup or catch cans should be considered a requirement.   The increased crank pressure can cause the street aos valves to fail which can ultimately lead to engine failure.

AOS help eliminate carbon buildup on the valves.  Does an AOS require a tune, STREET no, RACE yes.  Always best to have your tuner check logs post install to make sure you didn't induce a leak or cause a problem during the install.

After AOS install it is imperative to bleed the coolant system as you have introduced air bubbles which can cause overheating.

All AOS’s suffer from “sludge”.  They attempt to prevent this by running coolant through the can to heat the system, but the return line is not heated.  When the temp drops below 40*, moisture will accumulate in the return line and then mix with the oil and form the sludge pictured below.  This sludge is extremely common in cold temperatures and even more prevalent when using e85.  Running an AOS requires you to check this and either clean or replace the hose.  Many people run 3,000 mile oil change intervals due to this sludge and fuel dilution, but I took my car out to 8,000 miles several times and the Used Oil Analysis always came back excellent.  

Coolant bleeder

http://www.instructables.com/id/How-to-Burp-your-cars-cooling-system/?ALLSTEPS

basically put the funnel in, fill halfway with coolant, start car, let the car heat up until the fans turn on, then turn on heater, then blip throttle until bubbles stop. let car cool with funnel in place. Restart car and repeat one more time