Can A Catback Exhaust Make Your Car Faster?

Can A Catback Exhaust Make Your Car Faster?

Hello everyone and welcome, I am super excited about this video We’re taking the stock exhaust out of my car as you can see it’s out of the car And we’re replacing it with this This is a titanium exhaust and the reason why I’m so excited is because this video is going to be packed with Numbers test data, and so we are going to be you know determining What’s the weight difference between these two? What’s the sound difference between these two the actual decibel levels at different rpm? What’s the horsepower difference between these two we’re going to be putting it on a dyno and of course real world testing. What is the actual difference in acceleration before and after putting this titanium exhaust on now first off a big Thank you to this is the final video of a three part series where I’ve partnered with I’ll include a link in the video Description it’s a super cool website combines all the different used-car result websites into one website So you can just search in one location again I’ll have that link in the video description And thank you to AutoTempest for supporting this channel now this Exhaust in front of me is what I would consider the holy grail of exhausts for Honda s2000s This is the amuse euro s. It’s a single muffler version. I went with a very similar style to the stock exhaust Reason being is I didn’t want it to be too loud I think you know four cylinders aren’t the greatest Sounding engines in the world they don’t need to be accentuated any more than they are so I wanted something that was still decently quiet But significantly lighter and this entire thing this entire catback is made out of titanium. It is a beautiful handcrafted Hand-built custom order basically when you put in the order is when they start making it They don’t just crank these things out each one is made individually for each customer very beautiful piece of work Which I ordered from bulletproof automotive. I mean just look at these welds. How clean of a job they did with this it’s absolutely Beautiful and it’s titanium the whole thing is titanium so super lightweight now This is actually the same size diameter as the stock exhaust coming out of the catalytic converter 60 millimeters and the reason why I didn’t go any larger honestly, I don’t think the catback is what’s the restriction within the exhaust. That’s really going to come down to your catalytic converter I don’t plan on removing the catalytic converter So I don’t think it’s really going to be necessary to upgrade behind the catalytic converter I think exhaust flow will be fine does that mean it can’t make a power difference? No absolutely not so this has a much simpler routing less bends in it one single Simple path rather than that splitting path and the more complicated routing within the muffler’s So we’ll see I’m looking forward to the testing to see if there’s actually a difference in power between the two so our first Question what is the weight difference between the two well I’ve weighed the stock exhaust it came in exactly at 50 pounds 50 pounds for just a catback exhaust Then I weighed this titanium exhaust full titanium catback 15.8 lbs! 34.2 lbs saved pretty incredible that this exhaust right here is One-third the weight of the stock exhaust a little under a third of the weight of the stock exhaust even someone as scrawny as myself Can move this thing around quickly look how lightweight this thing is it’s absolutely incredible All right, so let’s get started with the installation, and this is a pretty simple straightforward process We’re gonna go through this fairly quickly first off we’re going to soak down the three exhaust nuts which we’re going to need to remove and Also, spray some oil on the exhaust hangers because these can often be stubborn to remove as well Next we need to remove the suspension stiffener There are six bolts that need to be removed to pull this off so that you can drop the exhaust out Now we can start with the exhaust removal first starting with the three catback nuts remove these Using a breaker bar if you need to as they do tend to rust and then pull the exhaust off the bolts and let it rest in place from here I work my way back removing the exhaust hangers along the way there are five in total starting with the one underneath Then there are two in each wheel well and it can be helpful to remove your wheels to give yourself better Access now when these hangers are removed the exhaust is quite Heavy and will drop quickly so to prevent damage have some towels under it or as you see here? I’m simply dropping it on to some old tires now I decided to use new mounts since the ones on the car are 15 years old But honestly they seem to be in great shape and I wouldn’t be concerned about reusing them in their current state there are Different hardnesses used for these mounts so if you do end up replacing them be sure to buy the correct part numbers Which I’ll have more info on in the video description installing the new exhaust is as simple as reversing your instructions place each of the rubber mounts on their respective hangers and slide the exhaust into place Then mate up the exhaust to the catalytic converter bolts and torque the replacement nuts to 25 pound feet or 33 Newton meters Finally we can replace the suspension stiffener torquing the for larger bolts to 33 pound feet or 45 Newton meters and the two smaller screws to 7.2 pound-feet or or 9.8 Newton meters now at this point you’ll notice there’s an extra exhaust hanger And I myself was a bit frustrated because I wasn’t sure why it’s welded on But it turns out there was a piece sitting in the shipping box that I didn’t notice this bracket can be mounted with the rear differential mounts and adds an extra mount to make sure the exhaust doesn’t contact anything nearby I Will say at this point if I had ordered the larger 70 millimeter pipe Clearance may have been an issue as there were a few spots where the exhaust was very close to metal on metal contact That said with all the mounts on it was very snug in place and now that we’re finished with the install it’s time for its Very first start up with the new catback All right So the install was a success and startup was the success always a good idea to check under the car make sure you don’t have An exhaust leak on that mating surface between the catalytic converter and the catback where you put in that gasket and now it is time To move on to sound testing so for sound testing I have this device right here This is an X Tech stl 600 measures and records decibel level So I’m placing it in the center because I want to have that in between the two exhaust pipes And then the same distance from just the single exhaust pipe, so it’s the exact same location For both test measured exactly where I place this and we’re going to look at decibel readings at idle at 3,000 rpm 5,000 7,000 and then just giving it some full throttle blips and seeing what the peak? Volume that it reads so for the stock exhaust was about 64 decibels at idle this is about 900 950 rpm somewhere in that range so 64 decibels at 3,000 rpm 75 decibels about 5,000 rpm about 87 decibels and 7000 rpm we’re looking about 95 decibels Get some full throttle blips how to see what it would say and it looks like the peak measurements were about 122 decibels and now we can listen in on the titanium catback testing So at idle we’re looking at about 68 decibels a little bit louder than idle for the stock exhaust As you can see a 3000rpm were floating around at 77 decibels At 5,000 rpm we’re looking at about 88 decibels As we get to 7000rpm, we’re looking at about 94, which is very close to the stock, but just slightly quieter And finally with some full throttle application you can see it peaking at about 122 decibels and Now we’ll listen a quick comparison between full throttle applications with the stock exhaust versus full throttle with the catback exhaust Okay, so there you have it as far as the sound comparison honestly Not a huge difference a little bit of a deeper tone With the titanium catback not a big difference overall which is slightly disappointing, but I’m also glad that it doesn’t sound You know ricey. I guess is the best word to say it doesn’t sound like it doesn’t belong on this car It sounds very close to stock. It’s just slightly more aggressive I think it could be a little bit more But I’m happy that it’s not way too loud And not super raspy or kind of whiny or rattley like some of the exhausts that you see out there especially on smaller Four-cylinder Honda engines now cool to look at is actually plotting these decibel levels With respect to time so on the left hand side the access we have decibel on the bottom We have time in blue is stock exhaust and in green is the catback and you know you can see initially Idling and there’s some peaks in there from wind and for me walking past things like that then you can see the range where it’s idling and you can see the catback in green is a little bit louder now You know I didn’t actually perform these tests with the intent of comparing them side by side with respect to time But it does turn out that they’re a pretty close overlap, so it is fairly easy to look at them You can see then as it goes up to 3000 rpm 5,000 rpm and then finally 7000 rpm they do stay fairly equal and then looking at you know kind of flooring it and just having those throttle Peaks The green one seems to have some louder spikes in there But overall you know they’re both peak around 120 decibels alright So next we have dyno testing moment of truth does this exhaust actually make any more power Okay, so here’s where it’s gonna get really ugly in the comments and that’s fine I’m okay with it, but basically what happened is before 183.5 horsepower, after installing 186 horsepower,. So this is a $2,500 exhaust and it made an additional 2.5 horsepower $1,000 per horsepower Probably one of the worst investments you could ever make and I admit that that’s true I do But I am actually really excited about it, and I’m excited about the dyno plot because you can learn from it and honestly That’s why I do these things. I don’t do it necessarily because I think it’s gonna make my car amazing I do it mostly because I want to learn now is it lame that it’s only two and a half horsepower Yes, but considering the fact that all that was changed was you took a muffler that goes in once up and then back down Versus a muffler that goes straight through at the exact same size the fact that you can gain 2.5 horsepower just from that simple change is actually pretty impressive and pretty cool to see Now why am I confident in the dyno numbers, and how do I know you know? How do I believe that it’s actually 2.5 horsepower increase? Well if you look at the dyno graph, What’s pretty interesting to see is then before VTEC kicks in yo at about 6,000 rpm both of the torque and the horsepower lines are basically identical Before and after flow isn’t super important at these lower rpms There’s plenty of flow through the stock exhaust even with that Bend, so it’s not a big deal Then after VTEC kicks in yo, you can see a noticeable increase in the torque curve the entire way across so there’s a little bit of a gap the entire way across from about 6,000 rpm onwards and As a result power is uniformly up across that that you know range of RPM So super cool to see you know this was done on the exact same dyno No changes were made to the car except for that catback and as you can see once flow becomes important Above 6,000 rpm it actually does make more power with the more efficient pathway of this Aftermarket exhaust now how can you make more power if you actually didn’t make any changes to the engine? This is certainly a question that comes up so I changed the exhaust it does make more power to the wheels that is a fact But people question that because it seems strange all you did was change something after the engine and so to think about it this way so that engine has to push out those exhaust gases and The easier of a time it has to push out those exhaust gases the less energy as it is spending Pushing out those exhaust gases so the more energy it can use to power these rear wheels if you have something super Restrictive if you just have a little pinhole right here your engine’s gonna have to work really hard to press out those exhaust gasses That’s that piston coming up forcing out those exhaust gases that requires work to do so that’s energy That’s not going to your wheels it’s instead going to pushing that exhaust out Well if you open it up if you make it easier for the car to push that exhaust gas out Then it’s going to have an easier time Doing so won’t require as much energy and as a result you will see higher horsepower at the wheels Very cool now is it $2,500 cool You know I can agree with almost all of you I’m sure on this and that no it’s really not and and this is a learning experiment right this video was done to learn it Certainly would not have been possible without so thank you for stepping in making this possible and we you know we all get to see some cool data as a result so now let’s move on to the final piece of Data, and that is real-world Acceleration testing so the way, I’m measuring real-world difference is before and after I’m using this VBox sport Connects to about 10 to 12 with satellites up in the sky determines You know your exact location and then measures time differences as you accelerate So what I did is you know three runs with the stock car in Second gear only second gear no shifting to eliminate shifting as a variable second gear We’re accelerating from ten miles per hour to 60 miles per hour We’re doing that exact same run three times then taking the average number of those three runs in increments of five miles per hour now I will show you the summarized data here so the average of those three runs for each of the increments Which I measured so you know 10 to 15 miles per hour 15 to 20 20 and 25 and so on Then I did the exact same test in the exact same location and I’ll talk about some of the ambient differences But basically exact same task just with the catback exhaust three runs 10 miles per hour Second gear up to 60 miles per hour took the average of those three runs and then compare them side-by-side now as a general summary if you take the 10 mile per hour to 60 mile per hour time and Compare it before and after you’re looking at 7.6 seconds with the stock exhaust and 7.30 seconds with the catback exhaust so an improvement overall of about 5% Which is actually pretty decent considering? I mean, it’s 34 pounds lighter And you know it’s a little bit more powerful and so as a result you do actually measure a real-world Difference now if we go back and look at our dyno plot You’d probably expect to see that most of that difference was made in the higher end where it makes slightly more power and that is slightly true So if you look at the 10 to 35 mile per hour time the catback exhaust is about 4.8% faster Versus if you look at the 35 to 60 mile per hour time or that engines in those higher rpm where VTEC starts to engage It’s actually 5.2 percent faster so a little bit faster in the higher rpm a little bit more performance gain in those higher rpms rather than the lower rpm and Across-the-board, it’s about 5% quicker ok so we have a car. That’s 1.2% lighter, and it’s 1.4% more powerful you might not expect to see a 5% power improvement And I think this is where the ambient conditions come in I try to do my test as close as possible But it just doesn’t always work out and so you know when I did do the catback testing it was 10 degrees Fahrenheit cooler Pressure was also slightly higher so both of those would help it make a little bit more power on the flipside Humidity was over double when I tested the catback then when I tested it with the stock exhaust So that would make a little bit less power, but overall we see a 5% improvement basically across the board in acceleration as a result of pulling out weight 34 pounds and Adding a bit of power to the top end about two and a half horsepower so although there Are you know environmental factors that can certainly affect it it also does have a measureable Improvement from the dyno and as far as you know obviously you have removed a certain amount of weight So this has been super exciting for me Hopefully for you as well learning very cool to see if you have not yet Please check out I’ve got a link in the video description Thank you again, Nathan CEO of Auto Tempest and fellow s2000 owner He actually Auto crosses his super cool to see so check out that website Thanks again for him sponsoring the video if you guys have any questions or comments of course feel free to leave those below And if you want to see any helpful links as far as some of the products use things like that in the video that will all be included in the video description

About the Author: Michael Flood


  1. Hope everyone's having a great day! A huge thanks to AutoTempest for making this video possible – if you enjoyed it consider sending some love to their website: as well as their Instagram, where you'll find photos of a beautiful AP2 S2000:
    And what did you think of this video style? I know it's longer than usual, and contains a much wider variety of information. Should this have been broken up into more specific videos, or do you like the format? Always appreciate your feedback!

  2. Never wanted to upgrade my exhaust for same reason….buuuut my dumbass forgot getting a lighter exhaust would be dank af. thx for da vid

  3. A titanium exhaust is like a carbon fiber intake – a really expensive way of doing something that could be just as easily done with steel/aluminium because the material used has nothing to do with the outcome, it's all a matter of geometry.

  4. 400 cool and you shoulda got true dauls long glass packs even if 5hp gain you can at least fall back on dauls sounding better then stock

  5. Tbh with the price and the single exhaust look , I would have chosen the stock exhaust or some dual aftermarket exhaust

  6. needs headers and high flow cat! and a proper CAI and tune. Then you might get 15-30 more hp =). But for a street car, you should focus your mods around stuff that builds torque, not HP. torque is more noticable and makes the car feel sportier at slower road speeds. HP only impacts top end speed.

  7. My RSX Type S made 207 wheel hp on a Mustang dyno and it had the old DC Sports TCS exhaust. My comptech raceheader eliminated the cat though.

  8. Not apples for Apple's for your sound test, and You are generally pretty through, but I think if you had added 32lbs to your car when speed testing your new exhaust, we could get a better picture of the performance due to design

  9. If you got a Custom built system at your local exhaust shop.

    It would sound better.
    It would cost about $400
    It would be Mild Steel so slightly Heavier.
    It would only last about 20 years and not 80 years like titanium.

    good choice 😀

  10. I'm a bit of a novice as far as automotive mechanics/engineering goes but does the less restrictive exhaust path get ya any better gas milage and longer engine life? (I know that isn't much of a concern if driving the car like a racer but some of us, no matter how we imagine/fantasize, usually drive quite reservedly or wish we did when refilling at the gas station).

  11. You get what you pay for; and that is a beautiful and professionally done exhaust. i paid about $1000 more for mine (including 2 headers, 2 high flow cats, and 2 mufflers) and mine doesn't look anywhere near as good as yours. Really enjoy your channel too.

  12. Damn 7 seconds for such a car is soo slow -( Have you considered the ambient temperature and the tyre pressure for the test accuracy after you fitted a new exhaust? And I'm sure a lot of people would be more interested if you did the same test with NO CAT at all -)

  13. What makes you think you will get power gains without a computer mapping tune ? This video is idiotic and you are if you do not realise this

  14. Do you understand how tuned exhaust works and what the point of them is? It sounds like you do not know what you are talking about. A catalytic convertor is not much of a restriction unless you have a crap cat in which case replace it . You need at least 3 dyno runs and average the results otherwise is it pointless, they are not accurate enough to do 1 run and think the result is definitive. Do you check the setup of the dyno first (gearing, elevation, temps etc)? Cat back is for idiots who do not understand how gas flow in a pipe works and how important a remap when you change your spec. Yo.

  15. see there is a change in variables tho. your engine before had two means of escape for the exhaust and pressure but you limited it to one, given more effective, means of escape. i would love to see the same test taken with two catbacks instead of one

  16. The reduction in mass is still a great thing though, because it gets slightly more useful work out of each unit of horsepower.

  17. Imo 4 Cylinders are the best sounding engines. They kinda mix the deep roughness of a v8 with the high pitch of a v6. Or at least that's how I'd describe it. To me v8's sound too rough and most 6 cylinders sound too raspy. It's all a matter of opinion at the end of the day 🙂

  18. I've had 3 different exhausts on my 2010 Camaro and can definitely confirm there's a big increase in performance over stock and over middle of the road exhaust systems.
    While I agree with one of the comments that the lighter weight does play a good part of better performance, one can't discount the fact that once cars can "breathe" better, they will perform better.

  19. I wish there would have been a way to test exhaust flow. Splitting the pipe for dual exhaust like the stock setup on a 4 cylinder decreases the flow. I can imagine the single pipe flows out hot gasses much more efficiently.

    Your gains being in the upper RPM make total sense considering better flow, less restriction and dealing with the most exhaust gasses at those rpm.

    What I want to know is how this same change would effect a turbo charged car. I'm guessing you may see gains as soon as the car has full boost and up, not just higher rpm.

  20. First off, love the videos, keep em coming. I'd like to say that it's worth the money, as long as it's affordable. This is why we're car people, or computer people, or whiskey, or or or. Cause we love to tinker and it's fun! Not enough time in the world or money in the world to do all these things every day it seems. I have one too many expensive hobbies…

  21. if it was a turbo or supercharged car, with intake, intercooler, intake manifold, ported, and cam upgrades too along with a remap, the exhaust plays a massive part on what power the car will make. so yes the exhaust upgrade is worth it if you are also applying the additional mods. my car has said mods except for cams and ported, it has a 3" decat downpipe, and 2.5" cat back no mid just back box running 289bhp. with a full 3" decat system im told i will get 305-310 bhp. but if i was to have the standard 2.25" with cat, resonator and back box, id probably only achieved 260-270ish

  22. The gain is not much for my corolla with an aftermarket catback exhaust, but it does look and sound so much better. It is also lighter too so helps with the performance.

  23. Even on N/A cars… Changing any parts on it does require a tune in order to see any performance gains…. Before a tune it is normal to see 2-3 hp increase but it can jump to 11-12 hp after a tune… Don't get me wrong, changing the exhaust is rarely done to have performance gains, it is more of an expression of the car owner.

  24. Depends on the stock exhaust. The muffler fell off my 96 Accord LX, and the car revved much more freely, and felt more powerful across the entire range. Even with the crush bends in the 1.75" pipe. Nothing huge. But any gain is noticeable and welcome on a car that made 130hp at the crank in 96. And then there was the terrible noise coming out of the rear….

  25. Might be expensive sure .. but your car is now lighter, way more efficient and you have a good base for any and all future upgrades.

    great job!

  26. Thanks a lot! U helped me to decide what to do with my 125i… pointless expend that amount when you just want it to sound “better” May be a removing the catalyzer would help a lot more

  27. 7 seconds to go from 10 to 60 mph !?! Geez I've always thought that the s2k was quick but I have a 20+ year old jeep that can do that.

  28. S2000 is a terrible example to test this principle on. Car came with a pretty efficient exhaust from the factory. Infact, most catbacks for that car by themselves lose horsepower…

  29. Please note that, wider the exhaust tube aft of the catalytic converter, denser the air will be due to the cooling of the exhaust gases. This is the principal of the working of refrigerant gases. Denser gases are more difficult to evacuate. Fundamentally an exhaust system is the most difficult part to design in an automobile because there are so many variables and physics takes a beating.

  30. I'm starting a study of exhaust, and a listed almost 25 parameters that are involved. If you don't consider the base ones like diameter, length and volume, you'll make something by feeling. I know a lot of this kind of construction here in my country (Brazil), people have a lot of life experience and make things by the feeling, like your new titanium exhaust. I'm not criticizing you, you made your car basically lighter, but if the constructor had a little knowledge in engineering the result would be great. You basically paid for the expensive material (titanium).
    Sorry for the bad English, if i say something wrong or that sounds offensive. I really like your videos. Hope we can change some knowledge. You seen to be a very good engineer.
    I know the video is kind old, but i hope you answer.

  31. I doubt if you will see any negligible increase with these type of mods because any car that has an ECU will adjust various parameters to keep it within the settings set by the factory. You would have to have a remapped ECU installed to take advantage of any mods. Same issue if you change to a more efficient CAT or worse…remove it. Removing a CAT altogether also creates a situation where the exhaust is nauseating stinky smell and can get unwanted attention. These changes also mean it won't pass smog testing if your state has that requirement.

  32. Seems like your exhaust already had a free flowing system. Well that and its a 4 cylinder. Still cool to see

  33. So considering you took out 35 pounds. How long till it pays itself off in MPG?
    Also, does this additional HP mean it's spending more gas or is this extra HP coming strictly from the alleviation of exhaust pressure?? 2500 bucks I'm estimating this exhaust pays itself off in about…. 2 or 3 years?

  34. If the flow restriction in the exhaust is lower with the new cat-back exhaust, you need to change the tune on the ECM to get the real benefit. The engine computer is fighting your output.

  35. To get the HP for $2k, no. To make it sound deeper and less annoying, with a HP increase bonus, and gas savings…maybe/sure.

  36. numbers are one thing how does it drive and respond to throttle input and it's really a work some of those welders are artists with their welds.

  37. It would be so much cheaper to go to a welder and have him make a catback for just a few hundred bucks. It have to be made of 304 steel so it would be a bit heavier.

Leave a Reply

Your email address will not be published. Required fields are marked *