How To: Greddy Supreme Exhaust Install On My 10th Gen Honda Civic Si Sedan

How To: Greddy Supreme Exhaust Install On My 10th Gen Honda Civic Si Sedan

Hey guys, how’s it going? Pawinn here and welcome back to my garage for another DIY technical video, it is awesome to have you guys here. In today’s video we’re gonna be installing this Greddy Supreme exhaust system. It comes in three components, the main muffler system the
exhaust tips are right in front of me and the two remaining pipes are right behind me.
After this video if you guys are interested in purchasing one of these
systems yourself, I’ll leave a product link in the description below. So full disclosure, I had been in the market for an exhaust system for a while now and
I’ve been debating on purchasing this system or a system from MAPerformance. My buddy Tristan was planing on trading in his 10th gen civic for a 10th gen accord, so he offered me the system, which is in really good condition… he only
drove about, I want to say a couple thousand miles on this exhaust system,
probably not even that much, but he offered it to me for $500, so I decided
to jump right on it. Now before we actually get into the disassembly of the
stock exhaust, I wanted to quickly go over what I actually did to prepare this
exhaust system to be installed into my car. Because I bought this [exhaust system]
secondhand, the first thing I had to do is actually order a new set of exhaust
gaskets. All I really did to get the correct size was measure the inner pipe
diameter that I needed, and also get a rough idea of the general shape [of the gasket needed]. After I got the measurements, I went online and and found the correct size gaskets from Vibrant Performance. Huge shout-out to them for getting me these gaskets so quickly, they literally came in like five days. So thank you for that. So for OEM [exhaust] hardware I went to BKay Honda parts in order to purchase a new set of
exhaust nuts. These exhaust nuts are the ones that bolt the front most pipe of
this exhaust system to the down pipe (or the crossover pipe that runs underneath
the oil pan of the car). Now in addition to these exhaust nuts, I also went to
Autozone and purchased a new set of exhaust bolts and nuts to piece together
the remaining two pipes of this exhaust system. of course I’ll try my best to leave product links in the description below in case any of you guys want to
purchase the same parts that I showed here. So the only thing that I did to
actually prepare the car for this assembly was spray a little bit of
penetrating [oil] on the three exhaust nuts that I talked about previously, as
well as spray some WD-40 on the exhaust hangers just to aid in the disassembly
a little bit more. The first step was to safely support my civic onto service ramps, and support the rear section on jack stands. Be mindful of any plastic trim components doing so. Locate 5x 10mm bolts and remove them to begin removing the belly pan Loosened/Removed them with a 10 mm hex socket + ratchet Following up the sides of the belly pan, there are 2 plastic trim clips that help secure it to the chassis Pry the center of the clip out to unfasten the clip. Then pull it out by hand. I found two more plastic clips in the center of the belly pan to remove in a similar way. condition of the front subframe after ~35k miles. Like I mentioned earlier, soaking the exhaust nuts/studs with penetrating oil helps free the hardware threads from corrosion. Spayed some WD-40 lithium grease onto the 7 rubber exhaust hangers to aid in their removal. Next, I removed the 3x 14mm exhaust nuts from the downpipe. Before removing the exhaust hangers, I decided to support middle of the exhaust with a jack. Then I proceeded to pry off 5x of the hangers, working my way back to the exhaust tip. Not sure how the rubber will age, but after 2 years the hangers were fairly easy to pull off the mounts. Working alone, I left the last two exhaust hangers on so I can lower front of the stock exhaust to the ground first. As I slowly released the jack, I was able to wiggle the front of the stock exhaust free from the DP. Now to pull off the last two hangars, I first supported the rear mufflers with a jack. Then I pulled off the remaining rubber exhaust hangers, and then lowered the entire system out from the car. Alright guys so I have the stock exhaust
taken off and I placed the Greddy Supreme exhaust system right next to it
just to get a better idea on how everything kind of lines up. Now I’m
going to need to transfer all the exhaust hangers. I noticed that I’m not
going to need the side most exhaust hangers at all, because if you look on
this exhaust there is no place to hang those, and actually overall if you just
look at both systems side-by-side this system is much much thinner than the
stock exhaust. I’m gonna get right to transferring all these exhaust hangers
and then we’re gonna begin bolting up Did a quick clean up on the exhaust flanges before installing any new exhaust gaskets. Doesn’t need to be perfect, but you want to get any loose corrosion brushed off and the mating surfaces ~clean. installing the front exhaust gasket. Fitment was a little tight on the studs, so I chose to drill out the holes for the studs with a step drill bit a tad. Now I installed the front pipe of the new exhaust system onto the studs on the DP. I installed a few threads on 2 of the exhaust nuts, then mounted the pipe’s exhaust hanger to the factory mounting point. Alright guys, so I’m pausing here
because I’ve run into a few issues. The first issue is that I couldn’t use one
of the three nuts on the last stud on the other side of the pipe here. I had to
use the original nut that threaded on. I think it’s probably just a different
[thread] size, obviously that’s my mistake. So for now I’m using the old nut to thread onto the actual stud here, but on the other two, they threaded on just fine. But
the bigger issue that I’m noticing right now is that the larger diameter [transition]
is actually causing me to have clearance issues fitting a socket around these
actual exhaust nuts Fortunately, I can still fit like a box
end of a wrench I might be able to squeeze in a ratchet [wrench], but this is
something I didn’t expect on doing. I’m a little bit frustrated but I’m
still gonna power through and complete this install. I balanced the mufller section of the new exhaust with a foam pad on the jack and carefully raised it up. Once I was satisfied with the height, I installed the 4x exhaust hangers to the factory mounting points. To fit the mid pipe under the car, I started by balancing one end on my jack so it holds to the rear muffler section. Doing so allowed me to install the other end to the front pipe with a new gasket and new hardware. Then we can bolt together the mid-pipe to the rear muffler section. I wasn’t 100% sure on torque spec to use on these nuts/bolts, but since they’re grade 8 I was confident a few zaps on my impact wrench would be sufficient. (will update if anything loosens). A few comparisons stock exhaust vs Greddy Exhaust from a few angles/cameras. Alright guys so we are back and it’s
been about a week or so, and frankly, I just I just got kicked out of this
parking lot that I was filming some final shots with. If you guys didn’t
notice I did change my taillights in the past week that I’ve been driving on this
new exhaust system so I’m still working on the video for that. So this Grady supreme exhaust system does a really really good job in
enhancing the lower tones of the exhaust note without necessarily giving it a lot
of drone. Cruising here around *2500* rpm there’s a little bit little bit of drone
here it’s a little bit louder on the highway when I’m cruising around in
sixth gear, but honestly you guys can still hear me just fine I’m not really
trying to raise my voice talking to the camera. I really like that it’s
aggressive but it’s not loud and I think my neighbors are gonna stay happy. Let’s see if I can get it let me see if I can get a good [exhaust] crackle here. oh my god.. every gear…
yes yes! I’m so stoked about those crackles for some reason because a lot
of people have commented and asked me if I had a [custom] exhaust in my car while the car is pretty much stock aside from the shifter mods. So aside from the slight difficulties with two clearances when installing this
exhaust system overall it was a breeze to put this exhaust system in. After
driving it for a couple days now, I’m extremely happy with the decision of me
with this part. So if you guys enjoyed this video please consider hitting the
‘like’ button and also consider subscribing to my channel below. Don’t
forget to check me out on Instagram and Facebook as well. I’m going to try to
post more of teaser updates with all my projects and products that I work with
just to kind of give a little bit more hype and anticipation before the videos
that are released afterwards. so with that all being said again my name is Pam song and I will catch you guys in the next DIY video, bye!

About the Author: Michael Flood


  1. I love how you documented the little snags like not being able to fit your socket on the new nuts…makes me feel not alone in this world.

  2. I know I say this every video, but Pawinn, your production value keeps making leaps and bounds over other auto YouTubers. I love these.

  3. This is awesome! I am planning on buying this very exhaust system. So much help for when us time for my install.

  4. I have the same exhaust on my Sport Touring and I love the looks and the sound. There was a bit of drone at about 2800 RPM for the first 10K kms. But as it broke in the tone has deepened and is very nice. It looks more natural on my Sport than your Si. 🙂

  5. Nice deep tone. This is what i want, but at 8:50 is what has me worried my driveway has a steeper angle and i'm lowered. I'm afraid the mufflers may hang a bit too low and may scrape going in and out of driveways.

  6. Your hangers came off wayyyyy to easy compared to what everyone else said. Lifting the weight of the pipe with your jack and wd40 seems to work real good for you. Im gonna do that.

  7. The only reason I didnt buy the greddy is because of the nut sack look. The civic sport hatch greddy looks so much better. I dont get why they gave the si those huge mufflers, which is why I ended up with the invidia r400.

  8. It looked like little truck nuts as you drove away. And you'll definitely bang those things against some speed bumps or ramps.

  9. I love my Greddy exhaust sound
    I’m not worry about those big muffler hanging.
    Nice video man
    By the way, where did you buy those ramps? Thanks.

  10. I feel like the greddy exhaust looks better on the coupe and the invidia q400 looks better on the sedan. Nice 10th gen btw

  11. You almost made me regret my decision of not buying the Si, but going with the 2019 Corolla Hatchback XSE instead. The quality of the video is excellent, but I still prefer my XSE. Much more fun and looks better. This is obviously very subjective as each one of us has a preferred taste that’s better to us. 🙂 Cheers.

  12. Two clearances? Now that you’ve had it would you recommend it? I wanted to go with the HKS but they are sold out and in back order, would you say this one is just as nice?

  13. Yo I had the same problem with the front pipe exit & greddy sp. My solution was use the OEM bolts & I didn't put on the gasket.

  14. The exhaut backs are too exposed like balls 🤣 no offense but they look ugly but your car is beautiful 😍

  15. Love my Greddy Supreme SP as well, one thing I had to do when I got mine was I had to air hammer out the studs on the stock front pipe and use new hardware supplied with the exhaust.

  16. Did you remove the muffler heat shields from the stock exhaust? Mine is rattling on startup when it’s warm and I believe the muffler on the greddy is hitting the stock heat shield.

  17. I have this exhaust, love the sound. But hate the play. Sounds like something is flopping around your trunk when you hit a bump.

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