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Discussion Starter · #1 ·
So I have a 2015 wrx bone stock at this moment. I ordered and have received the following parts and am curious if I need anything else or need to mod a few other things to support the build.
Mishimotos tmic, Mishimoto intake and charge pipe, catless j pipe, grimmspeed. 3 port ebcs, perrin light weight crank pulley, perrin light weight water pump pulley, perrin shift mounts, boomba short shifter kit, perrin aos, torque solutions egr delete, torque solutions tgv deletes, peErin equal length header. Thia is just for the engine at this time. I have suspension and brake parts as well and engine mounts and pitch stop etc. Is this a good list of parts to put on? it will be tuned professionally at a reputable tuner on a dyno. Any tips on other mods I may need or helpful adjustments?
 

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Thats a lotta parts. Have you discussed with your tuner your HP/TQ goals and if they are within the limitations of the FA20, specifically what the rods can take?

I think shifting the torque curve to the right so its peaking at higher RPMs, reducing the stress on the rods will help but unless you are building the bottom end you cant just go for broke.
 

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Discussion Starter · #5 ·
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I have discussed all the mods. I havent found much about the light weight pulleys or the header being used with the similar set up I am going for. I know that the rods are the weak point so I am going for 320who 360wtq. I know the way it is tuned can control the power to keep the motor from straining too much. I plan on building the bottom end down the road if need be but I do not want to destroy the motor just for a reason to rebuild it.
 

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For your goals, I think the header and crank pulley are unnecessary.
 

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I agree with Zax. Aftermarket headers tend to lead to an unnecessary wear item as opposed to something that adds real power, especially on the FA, since it already has an EL header.

On an EJ, the addition of a quality EL header such as Full Race or KillerB crafted from T321 is something long lasting, but at the same time, you're paying $2000 for 50hp reliably. I would return the header and put that money into a clutch, which you will inevitably need.
 

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Discussion Starter · #8 ·
Awesome advice. Why dont the headers not help the fa that much? Do the stock ones flow good enough for the power I am working towards? If I rebuild the bottom end later would the headers be a good mod or still lead to negligible gains?
 

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Awesome advice. Why dont the headers not help the fa that much? Do the stock ones flow good enough for the power I am working towards? If I rebuild the bottom end later would the headers be a good mod or still lead to negligible gains?
Your car isn't naturally aspirated -- the header primary size should be matched with the turbo. Since you aren't changing the turbo, you shouldn't change the header.

EDIT: You are changing the airflow characteristics slightly by installing an aftermarket J-pipe, but you have to understand that bigger headers don't necessarily make more power in a turbo mill. With turbocharged cars, you have to carefully balance flow characteristics with exhaust manifold pressure and velocity less you kill spool and reduce torque over the entire powerband.
 

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An aftermarket header WILL flow better, just not enough to justify their cost, and their replacement factor. That's my opinion. Others will tell you they love having an aftermarket header. Being made of a 304 steel and driven to excruciatingly intense temperatures , however, leave the metal in a fragile state after a couple of years. The header may help if you were to build down the road, that mostly depends on your power levels and the size of the runners on the header vs. air output of the engine.
 

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An aftermarket header WILL flow better
This is not strictly true. A Turbocharged setup is a positive feedback loop.

Manifold pressure and velocity drive the turbine in a turbocharger introducing more air into the system thus increasing manifold pressure and velocity. In typical American fashion, most people just throw on the biggest primary diameter headers available and assume that bigger = better. What this does is kill the exhaust gas velocity as now you have a larger plenum (so to speak) that allows exhaust gasses to expand and cool thus reducing the available energy to drive the turbocharger. Often, this just reduces performance.
 

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as above, since the FA20 has equal length headers already, you are ahead of the game over the older engine so the improvement isnt as great. I'd worry about the header once/IF you build the bottom end and put on a bigger turbo. Otherwise, not much to be gained for the $$ IMO
 

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How much dough tho
Ignore him. He is just going to complain because he bought a wrx thinking it was a corvette.

You have a nice group of mods there. I would take the advise given above and ditch the exhaust manifold and crank pulley. Put that money back, and contact the protuner that will be tuning you car. Run all of this by him and ask him if he recommends adding anything else to it that you maybe overlooked.
 

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How much dough tho
It depends on whether parts are sourced used or not.

New, it would cost about $5k to complete the list. I was able to do something similar in my bugeye for approx. $2.5k.

One disadvantage to owning the new chassis is relative lack of used parts.
 

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It depends on whether parts are sourced used or not.

New, it would cost about $5k to complete the list. I was able to do something similar in my bugeye for approx. $2.5k.

One disadvantage to owning the new chassis is relative lack of used parts.
The pre GR cars have a good used parts market. The GR and newer people are trying to sell used parts at 99% the price of new.

Yeah the list you have will get you started for sure. It will absolutely put pep in the step of that WRX. As others have mentioned I don't think aftermarket headers and light weight pulley are anything to invest in at the moment.

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