10 BEST performance mods for the 2015-2021 Subaru WRX/STI

Here is our top ten list for modifications you need to do to your 2015-2021 Subaru WRX & STI. There are a lot of different ways to shave lap times, increase HP, and improve your driving experience. Follow this path and avoid wasting your money on mods that don't work!
IAG Performance PTFE Fuel Line Kit for use w/ COBB Flex Fuel Sensor:
www.subispeed.com/products/ia...
Nostrum High Performance High Pressure Fuel Pump:
www.subispeed.com/products/h1...
COBB Tuning Top Mount Intercooler Kit:
www.subispeed.com/products/b4...
GrimmSpeed Front Mount Intercooler Kit WRX:
tinyurl.com/bdct29zd
Mishimoto Oil Cooler Kit WRX:
www.subispeed.com/products/mi...
Mishimoto Oil Cooler Kit STI:
www.subispeed.com/products/mi...
Koyo Aluminum Racing Radiator:
www.subispeed.com/products/vh...
Whiteline Front and Rear Sway Bar Kit w/Endlinks:
www.subispeed.com/products/bs...
GrimmSpeed Stealthbox Intake System:
www.subispeed.com/products/gr...
Cobb Intake:
tinyurl.com/yckuffrm
AEM Cold Air Intake System STI:
www.subispeed.com/products/ae...
PERRIN Performance J-Pipe with Catalyst:
www.subispeed.com/products/ps...
Grimmspeed Downpipe:
tinyurl.com/2p8pxpt3
Ohlins Road & Track Coilovers:
www.subispeed.com/products/su...
FactionFab F-Spec Performance Lowering Springs:
www.subispeed.com/products/1-...
Whiteline Adjustable Lower Control Arms (Rear):
www.subispeed.com/products/kt...
Faction Fab brake pads:
www.subispeed.com/search?q=Fa...
ATE Original TYP 200 DOT 4 Brake Fluid - 1L:
www.subispeed.com/products/70...
Brembo GT Systems 4 Piston Front Big Brake Kit Red With Slotted Rotors:
www.subispeed.com/products/1h...
Apex Race Parts EC-7 18x9.5 5x114.3 +38mm:
www.subispeed.com/products/ec...
Cobb Accessport:
www.subispeed.com/products/ap...

[@BaconNDCheese]

Pro tip, if you're gonna change top mount or front mount intercooler, just wait till you get the cold air intake too and just switch it all at once so you can tune it all at once.

[@growingup4487]

a bigger intake won't offer ant benefits unless you have a larger turbo to suck more air than the stock intake

[@christopherrogers8316]

he wasnt really saying anything about gains from a intake. more so just buy all at once and tune all at once. a intake on a wrx or sti without a tune is a no no. messes with the maf a/f ratio, more so on subies being very picky @@growingup4487

[@mroestarr]

@@growingup4487this is false.

[@steelersforlife9032]

You should do a video on how to set up the Cobb accessport and what you need to do it

[@godsplannn]

Dope video, really loving this guy along with Kevin! 🙌🏽

[@GTS300Coupe]

Thanks for the tips great video. I just realized a lot of these tips for quick and easy modifications will apply to a lot of turbo charged cars. Cheers

[@chocOneOOne]

I'd swap sway bar for coilovers because you can compensate for much more than a swaybar, plus the stock ones are pretty decent.

[@LeftSightScarFace]

👍 Great job 👏 , great video for the early morning 🌄 and my cup of ☕ coffee before starting work. Looking forward for more videos and products

[@jerodcombs2545]

Would love to see the catted j-pipe install!

[@roli710]

They have one already.

[@martinkalinowski2195]

great list 👍

[@alexartayet]

That silver STI ripping around Mid Ohio showing off his sick brakes is pretty cool! :P

[@reloadingdragon]

Yall should make a video on your opinions on the cancelled STI

[@MrHachirusto]

Great video

[@roli710]

Aos definitely number one.

[@MD-pz3cn]

Foster is the man!

[@LJV-12345]

good top ten I will add one the transmision carbon fiber

[@michaelanderson8042]

For the Wheel/Tire option, it seems you only mentioned a Street bias. What would you recommend for more off-road worthy? I live in Minnesota. I think I would prefer to stick with a 17" wheel to get more sidewall. Nasty potholes. I owned a 2008 Subaru Legacy Limited for a few years. Never got around to modifications though.

[@johnhufnagle7295]

I’d love to see the catted j-pipe install!

[@Biirdman]

8:59 he says "2015 wrx picks up 26 and a 2015 wrx picks up 30" I think he meant sti the second time.

[@merecumbe1000]

Thank you 🙏

[@calpsych6474]

Curious: what would you estimate the cost of ALL of that lace if you chose one item per each of your categories? in other words, what would be the cost of the full Monty...parts alone? parts plus labor if not installed via DIY?

[@pandawarriors33]

Please do the j pipe install!!!

[@mikecrean6168]

Great list but I think you should have given the cost some perspective as many of us are budget conscience. 1-6 Accessport first is good, but Sway Bar, Wheels & Tires, Brakes, Catback, Coilovers, In that order as the non tune items (also if you want to auto/Rally cross, not drag). I'd say Intake next as you can get a complimentary tune if you go COBB or MAP, but sneaking in the Turbo Inlet, Charge pipe and boost controller though easy and all good is a bit misleading and why I think those should be paired with J-Pipe and/or TMIC/FMIC as a pro/e-tune will be necessary unless you only buy Cobb (and still should probably be done). Lastly though I agree on your longevity and piece of mind call with Oil Cooler and Radiator, I also found it funny that the video showed headers but they weren't included, so lets add that to the parts stockpile (turbo inlet, boost controller, charge pipe, TMIC/FMIC, Headers, J-Pipe) before you throw them on and go get that pro-tune.

[@garettbond6182]

You seem like you know a lot about this stuff. Bc I’m a rookie when it comes to mods, what is TMIC/FMIC? And what makes the turbo inlet, charge pipe and boost controller easy? Also, what does an access port help with if I have no engine mods on the car yet? Why would that be good first?

[@dmvlogi7086]

@@garettbond6182 the accessport gives you access to a quick and easy base tune, aswell as giving you the ability to monitor multiple different gauges and ask lets you check engine codes. TMIC/FMIC stand for top mount intercooler(TMIC) and Front mount intercooler(FMIC) stock the wrx/sti come with a TMIC and you can upgrade to a bigger front mount to help support more power.

[@DAREDEVIL503]

I’m wanting to do a couple small things to my WRX, so I wanted to ask, is a Top mount Intercooler and a Cold air intake a good combo, I’m trying to get my WRX to Sit around 330 hp and my Dyno is 277hp

[@ashketchem9397]

I have Tein Z coils installed with a 18x9.5 +38 wheel. Tires are a 245/35/18 and I’ve experienced inner tire wall wear on the driver front tire…Would my suspension geometry be off if I’ve gotten an alignment done and no alignment issues were spotted?

[@SirChubblesSteen]

Which ducktail spoiler is on the blue WRX?

[@lyfewithpiglet582]

There is a company in Richmond Virginia who do amazing work on Subis. National Speed Richmond

[@Eri94]

Can't go wrong with carbotech's

[@elbandidosti]

AOS, Biggggggeeeeeer Turbo, Fuel pressure regulator, CF drive shaft, and a few more.

[@roddydykes7053]

Yeah was surprised AOS wasn’t #3 or so on the list

[@rmartinlim]

Is the AOS necessary for basic mods?

[@KSWKREW]

Let’s see that j pipe install .

[@ranran2218]

For an e-30 blend on a wrx you don't need to upgrade unless you plan to do higher mixtures.

[@edpartyka1581]

what kind of black rims do you have on the wrx?

[@armando2004]

What do you guys recommend for lower control arms on a 90% track use sti? Quality/safety being #1.

[@joeywu8888]

Cusco.

[@tjwreds1]

Mo Powa, Baby!

[@927Cole]

What's the name of those seats at the end of the video???

[@delonparkinson2491]

The fact that he has Donut media references I trust everything he says 😭😭

[@MonRoeTheory]

Hold up @9:00 ??? So a 2015 WRX is going to pick up almost 30 horsepower? But a 2015 WRX will also get up to 30 horsepower? Are you referring to horsepower to torque?

[@93stang19]

What is the mod for engine knocking ?

[@nikesbeast]

Aos tgv egr?

[@jordanjoestar8839]

Lots of owners did the "Buy an RS3" mod and its crazy to see them in the 10s with only that!

[@Syde_Project]

Only thing I’d add is water meth as a possible alternative for E85 as that’s not sold in all areas.

[@antweeezzyyyantop6743]

s tier donut reference

[@site60510]

Where in the bay area can i take my subi for mods like this

[@sickntired6241]

Great vid I’d say before doing the performance mods on your STI invest in a few of the longevity mods. First being an AOC, been running with the Cobb AOC for few years with no issues and it has removed the film of oil that used to live in my intercooler! Then I’d do the #4 cylinder cooling mod, the oil pickup/windage plate/oil pan mod, the brake master cylinder brace (the firewall does NOT flex anymore). Also got a performance radiator that performs outstanding. The heater is a bit cool in the winter AT IDLE only, other than that it’s perfect. Then go with the exhaust. Cat back with no time needed or full turbo back with a tune needed. “Let there be airflow” !! The factory intake is 100% the best but if you want the sound and a TINY bit of HP increase do the intake, charge pipe, turbo inlet and boost controller with a tune. All that being said. The very first thing you should buy, day one,! Is an access port. But beware some dealers will void the warranty. Mine did not on my 2020 STI. Enjoy your awesome car.

[@AnomieDomine]

After those, what would you do for power? I think I'd be just as interested in getting into the powerband/boost quicker than just making the HP number bigger

[@antabbysadventures]

I’d love a carb legal version of this

[@HooliganLuke]

Move out of California. Problem solved.

[@antabbysadventures]

@Uncky Hitlor I’m not from Cali 😂so I’m good their

[@nthgth]

*California, or a state that follows their emissions requirements. I'm in NY, it's just as much of a problem here. (believe me, I will get the hell out when circumstances are right)

[@antabbysadventures]

@@nthgth I’m from New York I just moved to Cali so trust me I know

[@nthgth]

@@antabbysadventures ah gotcha. I hear in MT not only do they not follow CAFE, with all their snow they still don't use road salt. Sounds like a Subaru tuner's paradise

[@johnnytrang5616]

What wing is that on the white rexy?

[@bagelsecelle9308]

Always start with the exhaust and suspension, cheapest compared to rest since you need to tune them (unless ur swapping TMI with basically the same as OEM)

[@heryang4019]

When is the red e-brake gonna be back in stock

[@miles8650]

ha he missed the red e-brake on the list

[@albert328]

its like you have lots to do after shooting the vdo, can you read your script a bit slower and add some pauses in-between different statements?

[@johnathanperez4348]

Mo powa baby

[@kupsteddy]

What seats are those?

[@Driven.Media.]

BRO BRO BRO WAIT!!! My name is also Foster!!!! We should immediately become friends or brothers now.

[@stevenathanassopoulos695]

Would love to see a video on how certain mods will impact the gas mileage on the wrx. I love mine, want to increase performance, but don’t want to make that 21 mpg TOO much lower. Was thinking of doing an intake, exhaust with a tube on my 22, any ideas how dramatically fuel economy will change?

[@flashsmith6799]

Pro tip, Mo powa = less mpg Mo air = Mo fuel to keep afr in the right spot

[@mogle4074]

I have a MY15 WRX. On the highway mixed with some urban driving id get average 7.5L/100km. Now on the highway with some urban I get 8.5L/100km. Mods are - down pipe - CAI - TGV delete - TMIC Definitely a noticeable increase in fuel usage especially when driving around town. About 40-50kw power increase at the wheels though so I wouldn’t change a thing. Those basic mods really bring it to life

[@Zaakro]

You bought your car for the wrong reason if you're worried about MPG.

[@billghinda9436]

would love to see a list of non warranty voiding mods❤️

[@SubiSpeed]

Got you! kzbin.info/www/bejne/nKrCgKR3iZqWl7M

[@nelc2399]

that would be lightweight lug nuts, lightweight wheels, racing tyres, bride bucket seats, carbon hood front and rear and car fragrance. 🙈🙉🙊

[@sevensonshelton3800]

Cat back Exhaust

[@kevmeister3063]

what exhaust was that 😳

[@andrewrippel6164]

Y'all NEED to link up and do something Subified with Donut Media

[@JoseHernandez-tz6xl]

Grimmspeed turbo inlet

[@braydenkline2065]

what mods are beat?

[@itsyaboimat2393]

Guys I have a question so I'm going to be buying a 2015 WRX CVT in 2023 (I have Cerebral Palsy so I can't drive a STI) for a daily driver so I keep hearing that the CVT will grenade itself is it just from driving the car hard?

[@bova57]

I got one and it just can’t go past 300 Hp because the cvt belt could fail going above 300 Hp. I’m pro tuned and running fine for a year now

[@RedM3]

You forgot the Kartboy Short Shifter with Bushings! Definitely a best mod!

[@ranran2218]

First modification I did to my 19 wrx. Hands down the best mod for daily driving!

[@toooodie8750]

ive been considering this but didnt know if it was worth the hassle cause i know its a bitch to install. Does it really make that big of a difference ? lol

[@ranran2218]

@@toooodie8750 the length of the throw is significantly less and you cleans up a lot of the slop between each gear so essentially each throw is shorter and more precise.

[@nikesbeast]

@@toooodie8750 naw get the Billetworkz kit bro. Trust

[@toooodie8750]

@@ranran2218 By far the best mod yet. Although, i didnt have to get under the car to do mine. Just did it in reverse.

[@kevg711]

The car behind him is an sti?

[@Krayzieboy99]

What was the exhaust setup at 4:43, I have 21 WRX so the closest I can get to this

[@OnomatopoeiaBoo]

MBRP race exhaust kzbin.info/www/bejne/baunmGx8ndqWqpo

[@Krayzieboy99]

@@rawj1213 naw no reply or comment

[@justchilaxe123]

Does tuning the car, say for the stage 1 COBB tune, hurt the engine in any way?

[@MTNorville]

It won't hurt your engine per se, but you shouldn't run an OTS tune for too long. Some do it for years and see no issues though. But they're just general tunes, and don't necessarily account for the air or fuel quality in your area.

[@justchilaxe123]

@@MTNorville Gotcha, thank you!

[@2sen]

An AOS should be added ti the list

[@ranran2218]

Aos or catch cans.

[@cmillan14]

I purchased the e-85 flex fuel kit but it turns out it won't pass inspection, was totally disappointed...

[@bjoewallace81]

Really? Wad going to do as well. U have an sti or a wrx Also do u live in ca

[@cmillan14]

@@bjoewallace81 WRX, I live in NY. I got tuned by Mikey Botti, he did 2 maps, one for 93, and the other for an e50 mix. I got an ethanol sensor to know the content, but they said they could not do the flex fuel kit and pass NY inspection which still doesn't make sense to me.

[@RobHTech]

Are there Subi dealers that work with tuners and OK a tune/after market upgrade without voiding the warranty? Also, will putting a cat-back exhaust without a tune damage anything and/or void the warranty?

[@restinginn9906]

What’s the cost for all ten upgrades?

[@thedon9670]

$15,000

[@gamingseeks3580]

i have borla catback on my 2020 series white wrx by next summer i'll have stage 2 pro tuning

[@lnol11689]

How do you like the borla exhaust? I'm thinking of getting a Tomei but I don't wanna be to loud.

[@gamingseeks3580]

@@lnol11689 borla is perfect tone not too loud i think it will get louder with j pipe and intake with tune but still not like those on KZbin my neighbors don't complain.

[@gamingseeks3580]

I'll see if I still have my video

[@gamingseeks3580]

Have to make a new video

[@lnol11689]

@@gamingseeks3580 I had some Delta motorworks catback but sold my 18' STI and the catback went with it i wish Delta motorworks was still making exhaust

[@enriquemontenegro5222]

#2 should of been AOS

[@enriquemontenegro5222]

#3 should of been short throw shifter with shift stop plate 🤝

[@jeffreyespinal3948]

AOS!

[@omgbeatz7039]

Where is Kevin from subispeed lol. Jk it’s nice to see more variety of people.

[@KevinVo]

Still here lurking in the background!

[@mrch33sehed93]

Most of these mods are great...if you're not registered in California 🤦‍♂️

[@JMart8755]

Lol L

[@PManti2010]

Time to move!! 😊

[@OsightblinderO]

Just don’t get caught 😇

[@jasondesouto919]

F California

[@chirsballer7133]

Lame state

[@JC-mq8dm]

I bought my 16-year-old son a 2014 WRX STI sedan. Was this a bad idea?

[@Acrimoniousbear1]

Wasnt your best plan for sure but if hes a responsible kid he wont wreck it. I dont think ANY 16 yr old needs a 300+ hp car. I did dumb things at 115hp. Hopefully he doesn’t try to mod it improperly (which alot of young people do) and blow it up. Basically if hes an honest kid that will decrease the amount of dumb things he may do but he WILL do dumb things in it. Hell im 39 and i did dumb things every now and then cuz these cars are just so fun.

[@BaldKiwi117]

Jesus christ the insurance on that is going to be ridiculous lmao

[@CourtneyKarl]

How's that working out a year later?

[@bobknight6394]

they dont sell e 85 here...

[@thedailyproject4569]

Install the j pipe.

[@justinturner4850]

There’s no E85 in Hawaii🥺

[@_wrx_WHPFaDIT]

To bad Cobb has discontinued there flex kit

[@AL-ux8pk]

TGV&EGR?

[@AL-ux8pk]

Oil catch can?

[@ryng2k1]

What's that WRX in the thumbnail?? 😍

[@thedon9670]

Subaru

[@erickquinones1095]

Best Subi STI mod ever..... get a GT-R

[@carlosfonseca2336]

bov to get the great sound

[@larosdav]

Bring back Kevin

[@codyc5762]

Guess clutches is not considered performance mod to you guys

[@Redcadence]

these are relatively light mods for non track dedicated cars. the stock exedy clutch is perfectly fine. if its on its way out, then sure. upgrade to a Exedy St. 1 HD with a stock resurface flywheel. anything harder and youll kill the fun imo.

[@carlosfonseca2336]

catch can

[@jessemartinez6781]

Bro just casually mentioned $15k worth of mods.... on a $15k car

[@oscarp9336]

Depending on when you made this video... Cobb is no longer any good unfortunately.

[@aron822]

Why is that?

[@oscarp9336]

@@aron822 on 4/28/22 Cobb was forced to make restrictive changes on the pro tuner application. These changes eliminate the ability to remove pollution control devices from your car. Unfortunately if you want to make real power these devices are in the way of that happening. They also made changes on how the throttle position and MAF sensor can be used to increase HP.

[@aron822]

@@oscarp9336 oh, thanks for the info! Just got my STI last week, new to the aftermarket tuning scene.

[@roddydykes7053]

9:00 Wut.

[@alwresendiz3826]

Where ISSS KEVIN???!!

[@KevinVo]

Here I am!

[@zbxck12345]

1st remove the spare tire for some weight loss, and its freee XD

[@nthgth]

"E85 flows 30% more" And my stock STI is already the thirstiest car I've ever owned 😄 good luck selling me on that one

[@SubiSpeed]

At least E85 gas prices are a little cheaper so it evens out (kinda)

[@nthgth]

@@SubiSpeed if it's 30% cheaper then sure. Like, the price that 87 octane was 2 months ago

[@ICON-11-]

Please lower your shipping rates to Hawaii, they're outrageous!

[@breezie_sti171]

@9:00-9:06 you repeated yourself "2015 wrx"

[@Kiss__Kiss]

He said, "Cold air" intake 😂

[@charleshawk6668]

Funny

[@IlovemySubaru]

E-85 will eat your motor up

[@nocomment8578]

20-30 hp gains for exhaust/jpipe swap. 🤣🤣🤣. Let's just not mention the tune requirements for this along with the fmic setup. Boys don't just upgrade and drive off! TUNE!!!!!

[@SubiSpeed]

yes always tune for engine mods, I mentioned that at the end but you are right!

[@gregmea1723]

First?!

[@lordskyblunt]

Cobb access port and tune is trash. it'll fuck your car up

[@d3mentia538]

#1 mod sell that piece of junk and get yourself an evo

[@user-bc8dn1ln8t]

Say you’re getting sponsored by Cobb without saying you’re getting sponsored by Cobb

[@tyreleriqson1032]

Just so everyone knows, SubiSpeed waaaay over charges.... they will delete my comment. Watch their advice and buy somewhere else.