Invidia Gemini R400 Quad Tip Cat-Back Exhaust

2015-2021 Subaru WRX & STI

$1,092.43 - $1,177.50

SKU: 5STIGM4SX-PARENTWe price match!


Add a powerful, mean rumble to your Subaru WRX or STI build along with a whole new look with Invidia’s R400 cat-back exhaust system!
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Titanium Tips
Stainless Tips
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SubiSpeed 2015+ WRX Video

SubiSpeed 2015+ STI Video

  • Mean, aggressive exhaust not with quad-tip look
  • Complete Invidia Cat-Back for WRX and STI
  • Throaty, raspy roar with downshift pop
  • Drop-in replacement for stock cat-back system
  • Backed by a 1-year limited warranty
  • Piping Diameter: 76mm
  • Tip Diameter: 101mm
  • Tip Material: Polished or Titanium
  • Piping Material: 304 Stainless Steel

Top 3 Exhausts for 2015-2021 WRX/STI

Provides your WRX or STI with a Vicious Sound and Great, New Look

Your 2015-2020 Subaru WRX or STI may be a powerful street and track machine off the showroom floor, but the factory cat-back sure doesn’t let you or your competition know it. Invidia’s Gemini R400 Cat-Back for 2015-2020 WRX and STIs adds a brutal, aggressive exhaust note to your wicked Subaru build that is sure to turn some heads on the street, autocross course, or drag strip. The Invidia Gemini R400 replaces your Subie’s quiet chambered mufflers with quad straight-through designs that let your track-ready WRX or STI sing at full volume without restrictions. Best of all, the Gemini R400 comes with a choice of tip finish so that you change up your WRX or STI’s looks while getting a whole new sound.


Smooth-Flowing, 76mm Tubing with 304 Stainless Steel Construction

Invidia’s R400 Gemini Cat-Back changes up your Subie’s looks and feel in a high-quality package. Each system is made out of 76mm, mandrel-bent tubing that provides smooth exhaust outflow to help support other power-adders and custom tuning. The system is manufactured entirely out of SUS304 stainless steel with a gorgeous polished finish that will make your 2015-2020 WRX or STI look classy at your local meet or at the track. The four angled tips are each 101mm diameter and are available in your choice of standard polished 304 stainless steel, blued titanium, or black finishes so that you can match your WRX or STI’s styling theme or paint color. The Invidia R400 cat-back installs right into place of your Subaru’s stock exhaust without the need for any cutting or trimming. Invidia backs their R400 Gemini System with a 1-year limited warranty.


  • 2015-2021 Subaru WRX
  • 2015-2021 Subaru STI


Check local noise ordinances: this cat-back system is loud enough that it may violate local noise ordinances. Please check local guidelines on noise levels before ordering.

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32 customer reviews

Average rating
(based on 32 reviews)
Ease of Installation
Fit / Quality
Overall Satisfaction
  1. Very Good

    By Aaron May 5, 2023

    The install of the exhaust was very easy. Only took about an hour and a half without a lift. The exhaust sounds very good, especially after breaking in (does some nice pops and crackles). Minimal drone but I just wish it was a little deeper and a little louder. Otherwise very good.

  2. Great sound and fitment

    By Sean March 25, 2023

    The install was easy with no problems whatsoever. It lined up with stock hangars and fit up with my Grimmspeed downpipe without issue. Sounds great with no noticeable drone in normal running. Not obnoxiously loud but not quiet either.

  3. Great sound

    By Dustin March 7, 2023

    Absolutely love this cat back. It has a nice deep rumble to it and the tips are beautiful. Only issue I had was the tips not being centered and I couldn't figure out how to get them centered but, this is the first cat back I have ever done myself so it was probably just a me thing.

  4. Great Set-Up

    By jambi0n February 20, 2023

    Purchased this back in 2018 after doing quite a bit of research and the team at SubiSpeed answered all my questions in a timely manner and was able to get me this set up within a week. While the competitors were on back order, SubiSpeed had these consistently. After installing, the sound wasn’t annoying and had that nice deep sound. My son 3 year old at the time enjoyed it that he would always were going fast when it rumbled.

  5. Worth it

    By Synchronize February 19, 2023

    Love the sound. Overall not to bad when it comes to install, would definitely recommend!

  6. Best Exhaust

    By Javi December 17, 2022

    Easy to install. I like the sound. Totally recommend this product

  7. Best Exhaust

    By Javi December 17, 2022

    Easy to install. I like the sound. Totally recommend this product

  8. Fair Price, Good Sound

    By MBZ December 15, 2022

    Install is easy as expected with a catback, the smaller mufflers give a lot of extra space to get those rear hangers in place. The price is good, but that shows in some places. The welds aren't the best, but they're not the worst either. Fit and finish on the tips is good. The sound outside is great. The volume inside the car is a little much for backseat or young passengers, especially on longer drives.

  9. Top tier

    By Brandon November 23, 2022

    Best exhaust in my opinion. Quality is the best you can find, installation is a cake walk, definite increase in power, and the sound alone is immaculate.

  10. Great look and sound

    By Jlia November 10, 2022

    Love the fit and finish of the exhaust. The sound is great when flooring, but nice and subtle when cruising. Titanium quad tips just look too good

  11. Great sound for a daily

    By Jlia November 10, 2022

    Shipped same day and received it 2 days later. Put on same day and the sound is very nice. You know it’s there when you floor it, but quiet when cruising. Install was straight forward and easy. The titanium quad tip is icing on the cake.

  12. Great product! Recommended!

    By Giuseppe October 11, 2022

    First off, props to Subispeed for the quick delivery. Purchased this on a flash sale on a Saturday afternoon, delivered on Tuesday afternoon. I'm not handy and don't have the tools so didn't do the install myself. Quality is very nice and welds look great. Fitment is perfect. Looks great, sounds great. Got the black tips version which looks fantastic paint matched to my black exterior. This cat-back gives you the subi rumble you want to hear without being obnoxious. Some might say it's not loud enough but my thoughts is that it's spot on with a minimal amount of highway drone. My 2020 STI is stock outside if this cat-back and I will say just the it definitely makes the care feel more responsive.

  13. Amazing Sound

    By Dave September 25, 2022

    These exhaust are really easy to install and they have the nice deep rumble. If you are going to connect to a stock down pipe I needed to get a donut gasket separately. It will still work but you could get exhaust leaks eventually

  14. It's a must if you like deep rumble

    By Worth every penny August 11, 2022

    Simple to install and this is what a Proper Subie rumble sounds like.

  15. Brings the WRX to life.

    By Tai August 9, 2022

    Recently bought this exhaust system for my 2021 Subaru Wrx Premium. Lemme just say compared to axle back exhaust system and a complete cat back system it completely awakes the beast that needs to be opened between the power and force this system does for this car is outstanding box came a bit damaged but everything was ship shape 10:10 on my list.

  16. Aggressive sound

    By Mike July 14, 2022

    The fit and quality of this is amazing. Not much adjustment needed to get the tips to line up. Install was quick, only tip I would give is do not use the provided gasket to connect to the cat. Keep the original o-ring if you can or buy one ahead of time to prevent leaks. The sound is deep and aggressive and it is loud in the cabin as well. It’s not bad enough to keep you from hearing your music but loud enough that your music will not drown it out. In 6th doing around 50-60 it does drone loudly but it has such a nice tone to the exhaust that it’s easily forgiven. If you like loud exhausts then this will definitely make you very happy.

  17. Aggressive sound

    By Mike July 14, 2022

    The fit and quality of this is amazing. Not much adjustment needed to get the tips to line up. Install was quick, only tip I would give is do not use the provided gasket to connect to the cat. Keep the original o-ring if you can or buy one ahead of time to prevent leaks. The sound is deep and aggressive and it is loud in the cabin as well. It’s not bad enough to keep you from hearing your music but loud enough that your music will not drown it out. In 6th doing around 50-60 it does drone loudly but it has such a nice tone to the exhaust that it’s easily forgiven. If you like loud exhausts then this will definitely make you very happy.

  18. Love it.

    By Szoke November 4, 2021

    Woke it up a little. Very nice. Louder without being annoying. Idle was -10.2 PSI now its -11

  19. Deep tone and loud when you want it to be

    By Enrique July 1, 2021

    Install was pretty straightforward, main thing that took time was trying to line up the tips evenly on both side. Got the stainless steel, looking good still after 2.5yrs of ownership. Would have gotten the black tips, but it was released way after I had purchased for a more stealthy build! Overall sounds so good and loud when I want it to be! Good quality product and I did received the product within a week or two!

  20. Great sound and easy install

    By ThePimpness June 20, 2021

    Overall install was simple. Everything bolted in with no issues and fit great. The sound is the best feature. There is no drone and when you get on it the quality is superb.

  21. No experience needed

    By Trevor February 28, 2021

    Never been one to work much on cars. It was pretty straight forward to do it yourself. YouTube install helps. Sounds amazing

  22. Amazing, fast delivery!

    By Andre January 28, 2021

    Let me just start by saying that I got this r400 in a flash received it in 5-6 days wow!! Being one of the most popular catback for the wrx sti just says how good this r400 is the tone is perfect maybe a bit to loud for some people. A bit of drone sometimes, but that all goes away by just hearing that sweet unique subi rumble tone that this catback provides. Quality is top notch 👌

  23. That good subi rumble

    By Connorinvegas January 20, 2021

    Installed on my stock 2018 STI after looking up videos and reviews I finally decided on the Invidia and let me say this is the perfect exhaust. Install was pretty straight forward and product quality was excellent. On first start up I knew it was a good choice very deep and has the exact sound and rumble I was looking for, after a couple revs my friends said “holy sh*t that’s the most Subaru sounding thing I’ve ever heard” no drone or annoying resonance on the freeway. Videos don’t do this exhaust justice, if your undecided just get this one you won’t regret it ;) 5/5 would recommend.

  24. LOVE IT

    By OZZY July 4, 2019

    Easy installation, fitment was great. brought my STI to love love the sound and shipping speed was surprisingly fast. only slight difficulty was getting the exhaust to line up center but nothing too dificult. Most definitely recommend this product.

  25. Great sound, brings out rumble. Quality control? not so much...

    By Anthony June 22, 2019

    Let me start by saying this, the R400 is a perfect exhaust for somebody that wants that deep rumble, not terribly loud, but just enough to give you a good smile when going through a tunnel or rev-match downshifting. However, my exhaust arrived with the box pretty damaged, the mid pipe flange was hanging out of a hole in the box. I wish quality control on these exhausts were a little better. The welds are next to terrible, and no matter the hanger, zip ties, or man-handling, I could not get this exhaust to sit where I wanted, evenly spaced and sitting flush with the bumper. It got to the point where it had burnt some of the plastic on my bumper unfortunately. Maybe this is just one in a million from them, i've had multiple invidia exhausts for different cars, always loved them and their quality, just wish it stayed consistent... I am happy overall, just wish QC was a little better.

  26. Wake your Subie up

    By Erick November 16, 2018

    This upgrade not only is super easy to install but also looks and sounds amazing!!! You can totally tell the quality in which is made from a mile away. I was able to install it by myself in my garage with jack and jack stands. The deep rumble brings a big o’l smile to my face. This must be the most beautiful sounding exhaust I’ve owned. The box came broken but didn’t notice nothing missing, Quick delivery though . I did miss seeing the laffy taffy Subispeed.


    By Steve U. September 22, 2018

    I have a 2018 WRX STI Type RA. And just installed the exhaust. It took longer jacking the car off the ground then the installation. I used the adapter which really assures a great seal. The revs are a bit snappier along with a bit more torque and a slight rasp which is cool. I have the stock down pipe and you can hear a slight turbo spool now. No drone sound to talk about. The cabin noise is a tad load but it drowns out the tire growl on the highway. lol Its definitely a nice quality piece. When you're in the pedal the car can be heard from blocks away and no need to beep the horn at those suspecting lane changers you might come across. I would definitely recommend this pipe.Once car was on stands it took all of 30 minutes to remove and install new pipe.

  28. Wrong Attach flange

    By Tom July 31, 2018

    The Exhaust installation was so easy on this system until it came to the attachment to the Cat Flange. On my 2018 STI, the flange that is on the CAT pipe is a conical where the flange on the exhaust is a flat. All Invidia needs to do is make this a conicle flange and it will fit both flat and conicle CAT pipes.

  29. Best Exhaust For The Price

    By Stephen May 5, 2018

    Installed SS tips on my stock 2017 WRX. Great rumble on cold start, pops on up shifts, and no drone cruising at highway speeds. Install is easy (1-2 hours), just have to play with tips to get them perfectly centered. SS tips look awesome definitely worth the wait and extra money.

  30. Clean fit, looks good

    By Ranzumze February 28, 2018

    Before install, checked with My Subaru dealer to make sure it was not going to void the warranty. They not only allowed this on a car with a full warranty, they even installed it for me. Has a deeper tone to it up through the gears, but not much louder than stock when at an idle. Much cleaner than the OEM exhaust, seems to breathe better, stainless steel will keep it in shape much longer, totally bolt on, very clean install

  31. Worth the wait

    By Mike August 6, 2017

    Ordered the SS tips when they where on back order knowing I would have to wait, thought it would be months but with in 20 days my order shipped. Installed was pretty easy, only issue was with figuring out the grim speed stock dp to cat back adapter. Quality is amazing and welds are clean, once you start your car it really comes to life compare to stock. Can't wait to add a dp to really open up the exhaust more.


    By MAU. STI May 4, 2017

    Overall easy install, had to play a bit with it so the tips were centered but nothing crazy... Once you start the engine HOLLY [email protected]#& this thing is crazy you will fall in love with your car once again... Totally recommend this product

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