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Invidia Gemini R400 Single Layer Cat Back Exhaust w/Titanium Burnt Tips ( Part Number:INV HS15STIGM4ST)

Invidia Gemini R400 Single Layer Cat Back Exhaust w/Titanium Burnt Tips - Subaru WRX/STI 2015+

Manufacturer Part # HS15STIGM4ST


MSRP: $1,467.00

In stock! Ships same day
Qualifies for free shipping!


RallySport Direct is proud to carry the Invidia Gemini R400 Single Layer Cat-Back Exhaust System. This is a great way to improve both the performance and sound of your vehicle. 

Here are more details:

  • Titanium burnt tips
  • 3" Piping diameter
  • 304 Stainless steel materials
  • Pronounced exhaust note throughout the entire RPM band
  • Exhaust hangers welded onto OEM locations to make it a direct fitment exhaust
  • New hardware and gaskets provided to make this exhaust ready for the installation
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Brand: Invidia
Exhaust Orientation: Straight Exit
Installation Hardware Included: Yes
Piping Coating: No
Piping Flex Joint: Yes
Piping ID: 3.00in
Piping Material: 304 Stainless Steel
Piping Taper: No
Silencer Included: No
Tip Material: Titanium
Tip Qty: 4
Tip Shape: Round
Tip Size: 4.00in

Mfgr. Warranty: 1 Year
Condition: New Product
Return Policy:

RallySport Guarantee - 30 Days

Items that are covered under the RallySport Guarantee offer a 30 day no questions asked return policy.

RallySport Guarantee items may be returned within 30 days of the original invoice date and must include all the original parts and contents for a refund.

The RallySport Guarantee does not apply to products that have been modified, damaged, misused or abused. All returns require an RMA (Return Merchandise Authorization) Number, and freight charges are strictly non-refundable. For more information regarding our freight refund policy, please refer to our return policy page found HERE.



Verified Purchase

2018 wrx base
donottouch 1 month ago
Pros Good qaulity catback system from invidia. Easy to install All hardware and gaskets are included. Nice deep and loud tone. Burnt tips look great Cons Has a little highway drone/ not to loud though, but loud enough to forced to turn my music up to get rid of it. Fitment of the mufflers are not exact, one side is too close to the inside of my bumper fender. I had to run on one hanger so it dosnt touch. There were no instructions at all. No pictures nothing at all that i can reference to my specific year. Alot of wrong info given on this site, for my 2018 wrx base model you dont need to purchase a 3in adaptor to connect oem downpipe to the catback. It all bolts on, just use the nuts and bolts provided that came with the system. The exhaust is great but too loud for my liking i should of just gotten the axel back. Rally sport direct is a great site with good prices, shipping came a day ahead schedule.
Verified Purchase

Fits great, sounds even better.
jaybelly 1 month ago
This cat-back installed very easily and sounds really good! Definitely felt the increase in power when I went from Stage 1 to Stage2+ (j-pipe/cat-back/intake). The burnt tips also look amazing!
Verified Purchase

Sounds great on my 2016 STI
NikkoNikko 2 months ago
Quick delivery from RSD i received everything in record time! Dont forget to buy the stock downpipe to 3in exhaust adapter when installing this. Everything in the box was undamaged and all gaskes, screws, and bolts were accounted for. Install is easy by yourself but even easier if you have a friend. I decided to go with the r400 after i heard my friend's Q300+Invidia Downpipe and wanted something louder than that and on top of that it wa son sale at the time. I can say after install the r400&stock downpipe is louder. Cold Starts and nice loud but once it warms up and idles it isnt an obnoxious loud. On the Highway it's bearable. That Subie Rumble completely opens up from the stock exhaust. Sounds great on "spirited" drives. Youtube Videos do not do this exhaust justice. I highly recommend the r400!
Verified Purchase

I dig it
Darth Subious 5 months ago
Fits perfectly with the Invidia catted J-pipe. Oversized tips don't touch the bumper cover. Sounds good. Not very loud. Has a yuuuge resonator on the mid pipe with a flex joint near by. Easily replaced with the help of a good TIG welder.
lcrivelli699819 1 month ago
Do you have a WRX or STI?

Cat Back
The_Beast_Quake 6 months ago
So sweet! I paired it with a catless DP. Car sounds perfect to me, no drone just a nice hummmmm! I had Walter from Simple Performance SLC do the install since he is the exhaust magician :)

  • Q: Difference between the 2014 and 2015+ WRX  BU24U 9 days ago


    I have the R400 for my 2014 WRX I'm trying to sell to a friend of mine, but they have the 2016 WRX. I looked at the pictures for both years for the catback and couldn't find any differences. Could you tell me if it'll work, or not at all?

    • A: We are not able to confirm fitment but the chances of it fitting are slim to none.

      Jared A. 8 days ago
    • A: It fit perfectly! I'm so glad I did it! I believe I'm the first to accomplish this with the help of my buddies! There were no issues. It all fit perfectly! In yo face! 😂😂😂

      BU24U 4 days ago
  • Q: 2018 WRX Base model  donottouch 1 month ago


    I have a 2018 WRX base model, do I need to buy anything else to make cat-back system fit?

    • A: You will need the following links for installation with the OEM downpipe.

      Jared A. 1 month ago
    • A: Info given was incorrect, you dont need the 3inch adaptor to fit the oem down pipe to the catback system. You also dont use the oem doughnut gasket, a flat gasket is provided in place of the doughnut gasket. Shipment came in last week and did the install a few days after. After inspection of the stock system, and comparing it to the new system, it is all direct fit bolt on. This review applies to the 2018 wrx base model. Not the STI model.

      donottouch 1 month ago
  • Q: 2018 STI Gemini R400  airforcekp 3 months ago


    I currently traded in my 17 WRX for a 2018 STI. My question is I had the Gemini R400 on my 17 WRX, will that fit to the 2018 STI? Or do I need A adapter? And if I do is it possible to post the link to the adapter thanks.

    • A: This exhaust will fit your 18 STI, you'll want this adapter for it to fit properly:

      Marcus E. 16 days ago
  • Q: Exhaust Sound Comparison to 2017 Stock Subaru STi Exhaust  ScoobySTi 3 months ago


    How does the sound of this exhaust compare to the 2017 Subaru STi stock exhaust? I saw some comments about folks stating that this exhaust is "quiet". I know there are videos out there, but it's hard to gauge based on the ones I've seen.

    • A: The R400 is meant to be Invida's mid-level sounding exhaust.

      Luis L. 16 days ago
  • Q: OEM to 3inch adapter  Matthew W 3 months ago


    I have 2018 wrx premium and its been brought to my attention that if i purchase this exhaust i will need some special adapters? Where can I purchase a OEM to 3inch adapter and how much is that part?

    • A: If you are installing this exhaust to the stock downpipe, you would need a Stock Downpipe to 3" Catback adapter. Grimmspeed does make one, which you can find by searching Part # GRM 077046

      Brady R 1 month ago