Off topic, but I would love to see you post a to do list for a "stage 2" street build that you would drive... and then answer all my questions!
I'm always happy to answer any questions! That one is pretty easy because I recently posted the same topic on Instagram because I get asked this same question quite frequently haha
I'll preface with saying that I've never been a COBB "fanboy", but I'm very impressed their recent re-designs of their products..
What are the "BEST" bolt-ons?
This is a highly subjective & controversial topic that depends on how you define "best", but below are the parts that I personally recommend based on the criteria most valuable to me: Engineering, Performance, Quality & Support (of both the product & Subaru community). The modification must improve volumetric efficiency without compromising reliability or being obnoxiously loud. You'll also see that I'm a big proponent for thermal management.
*Killer B Motorsport 4-1 Holy Header w/ SwainTech Coating
@killerbmotorsport symmetrical, equal length header (ELH). There are so many reasons that this is the "best" header in my book.. from the engineering, design, materials, coating & lifetime warranty.. I actually purchased this header before deciding to go with the VF58 twin scroll conversion. This header is my #1 recommendation.. along with SwainTech's White Lightning coating being my #1 recommended ceramic coating.
*NEW COBB GESi Catted 3" Downpipe + Ceramic Coating (SwainTech or Cerakote coating)
COBB has stepped up their Subaru game recently. From an aesthetic and engineering standpoint, I appreciate COBB's cast bellmouth design. Now that they've added a GESi catalyzer, it's earned the #1 spot on my downpipe list. I also like that their downpipe has the option to retain the OEM donut gasket & spring bolts. I do wish that they offered a ceramic coating option. Of course, I'd recommend SwainTech's White Lightning coating.
If you're not familiar with high flow GESi catalytic converters, they're one of the very best on the market in terms of performance and reducing emissions. COBB's new downpipe features a 3" high flow, 300 cell catalytic converter that's rated for over 500 HP while still being EPA certified (reducing up to 99% of harmful emissions). The catalytic converter core itself is ~$400. Almost every other downpipe on the market goes with an undisclosed, lower quality "high flow" cat.. often with a lower cell count. It's funny because I posted a few months ago that my ideal downpipe would have their bellmouth design combined with a GESi cat towards the rear.. coincidence or just that great minds think alike?! 🤣
Why do I recommend a catted downpipe? Simple, a quality catalytic convert will keep the setup legal (in most states except California), it's environmentally friendly, and prevent boost creep (improving safety/reliability) while having a negligible impact to performance.
*COBB Titanium 3" Catback Exhaust
This is
HIGHLY subjective. But COBB offers one of the best catbacks on the market IMO... a lightweight, dual muffler, quad-tip, titanium exhaust that comes in at 24 lbs (~50% lighter than the stainless steel alternatives). This will shave ~20 lbs +/- compared to the factory exhaust while producing a relatively mild, but unique exhaust note due to its titanium construction. I'd personally add a
Vibrant Performance titanium resonator to keep things extra quiet and ensure a drone-free experience (I guess I'm getting old haha). I'd also like to see COBB offer an option for a set of more mature rolled, brushed titanium exhaust tips (similar in design to the tips on their stainless steel catback).
*Intake: COBB Redline Carbon Fiber Intake OR the OEM S209 Intake w/ a DryFlow Filter
COBB recently released what I consider to be one of the best (and only) aftermarket intakes that I recommend. A true cold air intake constructed of stylish, lightweight carbon fiber that will better resist heat soak (compared to a metal intake box). It should also produce a more mild, mature induction noise and shave a bit of weight compared to the stock airbox. If not for this intake, I would choose the OEM S209 intake.
*Boost Controller: GrimmSpeed or COBB 3-Port EBCS
A 3-Port EBCS is a no brainer before getting a protune. We'll want it in order to more precisely control boost now that we've significantly reduce backpressure increasing the intake & exhaust flow, thus improving volumetric efficiency.
Thermal Management (Reducing radiant heat transfer to the TMIC and lowering IATs & post turbo manifold temps):
*GrimmSpeed's V2 Turbo Heat Shield (Ceramic Thermal Coating & DEI Reflect-A-Gold Foil
*PTP Lava Turbo Blanket
*Protune
At this point you've maxed out the stock fuel injectors in 4th gear at higher RPMs. Skip the intake if you're worried and/or have your tuner dial the boost back in 4th gear and higher to be more conservative to lower IDCs a bit... I mean how much time do you really spend at ~100+ mph anyways?
If you do truly track your car and want to maximize reliability, you should look into upgrading the Fuel System to go "Stage 3".
Fuel System:
- COBB/ID 1050x Fuel Injectors
- AEM 340lph Fuel Pump (E85 compatible)
- COBB/IAP FPR "fuel stumble" kit
- COBB Flex Fuel Kit (E85 should offer ~ +50 whp/wtq while more importantly reducing knock tendency)
Now you've maxed out the stock VF48 turbo (probably around ~350-360 whp or so with well over 400 wtq). Luckily there's a
great, reliable, budget OEM turbo upgrade option:
*IHI Turbo Performance's VF48 HF (Hi Flow) Turbo
Thanks to IHI installing a larger & lighter billet aluminum compressor wheel, the OEM+ VF48HF is capable of supporting over 400 whp for ~$1,000 USD while appearing completely factory. I'd also recommend having a reputable turbocharger porting company (like SoCal Porting or Turbo Parts Canada)
Port the Turbine Housing (Turbine inlet & wastegate) to maximize the potential of the restrictive single scroll turbine housing and reduce boost creep. The setup above should produce ~400-420 whp while spooling (reaching boost threshold) as fast, or faster, than the OEM VF48.
This is the setup that I would do on my personal car if I hadn't went down the twin scroll conversion route. This would make for a perfect daily driven, high performance street car with occasional track use. Of course, I'd spend the extra money and have my great friends at Advanced Sports Engineering Lab perform a ball bearing conversion on the VF48 Hi Flow.. because I believe in having everything overengineered 😁
