Do Catback Exhausts Increase Horsepower? (With Proof)

[@Sens23Bruins]

So engineers really do know what they're doing after all...

[@ninjarooster9258]

Some do, but in my experience they are few and far between.

[@Bazuzeus]

Of course not! They are just lucky... sometimes :D

[@onetimeracas5972]

NinjaRooster Isnt that the truth!

[@doddgarger6806]

They just learn how to try harder, and the math needed to quantify results, no magic involved...

[@jonwal]

I'm looking forward to the Integra project videos so much. Keep up the great work!

[@EngineeringExplained]

Happy to hear it!

[@solaman095]

restriction at the exhaust header?

[@Hoodratliker]

any time you can make your engine breathe easier, whether its inhaling or exhaling, its good for engine power.

[@derrickjones7282]

Ecu tuning aswell

[@HexifiedGaming]

Think of an exhaust system as a multiplier. (Example, not actual stats) Exhaust = 2% Exhaust + Intake = 5% Exhaust + Intake + Tune = 10% An exhaust alone will do nearly nothing by itself, same for an intake, but both of them together multiply each others performance. Every engine will have different results along with different stock parts to work with depending on model. If you want to greatly increase horsepower, your best bet is to research the best Exhaust + Intake + Tune combo for your engine. Currently im looking for a combo that will bring a 300hp 05'-09' Mustang GT to around

[@TheBikemaster94]

HexifiedGaming 400 ci. Craigslist special, I see Malibu and montes going for 3k . They're all Automatic in that price range if that's a deal breaker.

[@billdaggett7911]

You'll never get 120hp gains from a catback, intake and tune. Not even with headers, full exhaust, cai, and tune. You'll need a cam and maybe headwork.

[@cbass4017]

10% stop watching fast n furious its more like 5% maybe = exhaust+intake+tune if you got stickers you can get 7%

[@scarea2691]

@@billdaggett7911 but ecu and dyno tuning on turbo engines can really increase power, or at least usablility

[@billdaggett7911]

@@scarea2691 that's a turbo engine. Turbos are intentionally oversized so that they operate in a safe range for durability. Increasing boost reduces turbo and engine life and makes more power. That is not possible with Normally Aspirated engines.

[@losertheteacher]

I love what you are doing man. Keep it up. I would love to see readings like this for lightweight Crankshaft pulley or Lightweight flywheel. There is so much talk about these things on the forums we really do not know what to believe.

[@Jaggbrony]

Perfect example of how "easy performance" mods don't work no matter how much companies will tout "10 hp gain or whatever"(unless the system being modified is super restrictive, or they tested on a best case sinerio a.k.a modded vehicle). It's all down to how effective the engine is at moving air, because an engine is really a fancy air pump. I expect to see the same result when you get around to a CAI. Assuming no cams or FI are done before hand. Definitely going to use this methodology when I get a catback and a SC under-drive pulley for my Mini, to see what the difference is between all the combinations. Good video, can't wait to see more!

[@tpz7618]

Man, I really love your videos, but I wish you would also make a "long story short" version of all of them.

[@DavyDave1313]

LMAO

[@zb9568]

Lol 😂

[@vtracing1765]

Yes

[@marcellismadness2552]

Then ud miss the science

[@not-AI]

1.5x playback my guy

[@ghettoflyer]

Great job on consistent test procedures. I would encourage you to upgrade/ replace posi, clutch/pressure plate, and CV joints. One of the first things to go is going to be the clutch, posi ( if it has one), or CV joints... Only a slight upgrade on these parts ( stage 1 or 2 ) will make a vast improvement and make the car more consistent when testing parts and make ready for more power in the future.

[@theClosetgrower420]

This is awesome, I basically have the same exact car(same color even) and I really like how meticulous you are and how well you explain what you're doing and explaining the results of your testing. I am also in the process of modifying my car(slowly but surely) and I had the same exact exhaust system on my list to purchase next and I really like how it turned out on your car. The sound it puts off is exactly what I was looking for and now I know exactly how it will help/hurt the car. Oh yea and now I know what problems I can expect when installing it as well. Maybe install a simple short ram or even cold air intake to help let that new exhaust show its potential and test the acceleration again and I'm sure you will see more significant gains from stock. Good work man.

[@chilledboost1982]

I'd like to see this after installing a header

[@connorbamber8001]

Exactly! :)

[@Mr401MoUa]

That would make a big difference

[@intrepid_wandering]

I think that's should certainly be next. After the cat-back your next upgrade really should be a header to complete the whole exhaust system. Also I don't know if it fit's into your agenda but a proper tune starts to be very helpful right around this time.

[@H8MadXero]

Mike M Tuning is costly, especially when considering he would have to buy an ECU as well...he'd see more gains per $ after a few more mods imho (ie CAI and Cams/IM (I grouped these together as they really compliement each other)). I would start with a CAI then add cams/IM/ecu and tune all at once.

[@intrepid_wandering]

Speed Junkie For some reason I though he already installed a CAI. In which case that should be next. But I agree completely. Putting some performance Cams in would be exciting

[@GMWsho]

I LOVE your acceleration tests :D.. well all tests in general... well all videos about your Integra. more please. I will finish all the rest of them by the end of the day...

[@SuzanneKowalski]

a couple of days ago i was sitting on the toilet and something came in my mind about weight reduction. there is one factor you never talked about and i don't remember anyone mentioning it: tyre pressure. less weight equals less stress on the tyres, they don't deform that much and thus create less rolling resistance, which affects acceleration. okay, anyhow, i admit that calculating the tyre pressure versus deforming is nearly impossible, but i'd say that a little less air in the tyres (around 0.05 - 0.1 bar) could have done the job, and meant one less factor to worry about. (anyway, lower and higher tyre pressure and their effects on acceleration might be another subject of testing...)

[@Dogzero33]

I thought lower tire pressure also increases grip? although close to flat tires i don' think you will get you too far) haha xD

[@mactwentytwentyfour]

Dogzero T T It increases grip but lowers speed

[@katanamd]

Dogzero T T More grip, but more drag as well. So it will help reduce wheel spin but hinder you once the spin stops.

[@bonferoni6664]

These testing videos are awesome. Keep up the great work.

[@bigcazza5260]

depends, if the factory one is restrictive and depends how big the factory log manifold is yes +5hp maybe factory vs aftermarket. 20 year old factory vs aftermarket up to +20hp depends how blocked old mufflers and cat are. u need extractors

[@cubanamerican22]

Weight is a great factor, I just replace the catback on my Tundra and I needed help taking the old muffler out lol it was probably 40 pounds heavier than the new one.

[@jasonschmitt44]

So works better at higher rpms..... cant wait to put cat back on my 99 vtec prelude!! BWAAAAHHHHHH

[@bob-a-louannamaria7960]

Schmitty 1e1 it’s still gonna be a 99 vtech prelude. 😂🤦🏼‍♂️ yawn

[@4door_papi]

Bob-A-Lou Anna Maria its vtec*

[@studiopk2004]

Preludes dont go bwaaaaa subies do

[@Foukos91]

@Engineering Explained I dont know if someone else mentioned that before but it is an importand note. The percentage of power increase is not the right one. As you modify the engine more by the time to get a better horsepower output than the stock 140hp,a part of the power gain will be exhaust gain,as the exhaust's inner diameter will be more relevant and suitable for the engine's power output. Correct me if Im wrong,we are here to learn! :)

[@Dcc357]

I installed a cat back because I wanted my truck to be louder. Any HP gain is welcome.

[@p2sam]

I like the methodical approach you are taking with this.

[@KramuWu]

Would adding a catback to a car with CVT potentially be more effective or less effective than adding one with other transmissions? The cvt's RPM's tend to stay higher longer so does that mean the exhaust would be working better for a longer period of time?

[@DrNoro]

If it's not too much to ask is it possible to make a video to see how much acceleration is affected due to octane rating or different brands of gasoline. For example shell versus mobile 1 or Costco versus Sam's Club. -thanks Noro

[@EngineeringExplained]

I'll have some future videos on octane levels that I think you'll find interesting. Wouldn't make any difference on my Integra, as it's designed for 87.

[@Nisspecvan]

I can't speak to the different brands of gasoline, but I do know higher octane for a car that only needs 87 will not give you any extra performance to speak of. Its not like Nos where you just get more power. Octane is strictly the resistance to detonation. If your car doesn't call for it, its not necessary, unless you have certain mods.

[@TheSigp220]

Pick up some 4:2:1 headers and some cams next. then get yourself a stand alone ECU and get some ITB's. after you get to where you have a good gain and drive it for a while, rebuild the motor with a higher compression ratio. You'll have to run a higher octane gas and you'll have to tune the ECU to do so but if you're making it a race car anyway it shouldn't be an issue. After that, depending on your application you can run a dry shot of NO2 into the throttle bodies and have one seriously fast car!

[@vacomments]

This is a fast reasoning, so it can well be a wrong one. Its possible that one could measure the acceleration difference while applying multiple gears in one run, and at the same time, discarding the inconstant time of manual gear changes. We find the nº of frames that it takes to go from aKPH to bKPH in 1st gear. Then, in 2nd gear, we find the nº of frames that it takes to go from (bKPH - 5) to cKPH. Then in 3rd, from (cKPH - 5) to dKPH. In 4th, from (dKPH - 5) to eKPH. (The '5' is just there to produce a 'grey area' in between gears, so that there arent any discrepancies, thus a higher value could be used) We add the nº of frames in all gears (while ignoring the nº of frames in the "grey" 5 KPH of every gear) and we can calculate the acceleration time. This would be a test where all gear changes are seamless, therefore the acceleration time would be non-representative. But i think it could give us a representative % difference from one exhaust pipe to the other. Im not 100% though.

[@mortezaafkhamipour2737]

I have installed the cutback on my toyota corolla GLI 2015 with 2000 cc and after some tests I found that the acceleration increased but fuel consumption also increased. This happens when I run the car in gear 2 thanks for your video

[@jacobc.8489]

Exhaust is going to bring more noise and MPG over anything. It is fun to lay into tye throttle and hear the tone...I just installed a Jpipe, test pipe (3rd cat delete), catback-magnaflow mufflers. I noticed A LOT more throttle responce and I couldnt stop smiling 😄.

[@Giuliano_Capecchi_SF]

Great experiment! Always worth watching your tests! Congrats !

[@GUAMchild671]

I suggest to get a baseline run at your local track, then do your upgrades and test it again to see if any time difference ;)

[@EngineeringExplained]

I think my driving skill would create more significant time differences, so I reverted to something I knew was repeatable.

[@Bizzenn1976]

From various videos I've seen regarding exhausts and air intake systems, it seems like just adding a more free flowing panel filter and just replacing the stock muffler with a better flowing one will have the same effect has the latter while saving a ton of money. If a vehicle already has say 2.25 inch piping or better depending on the power it makes, then one would assume that it is designed for that diameter of piping and just making the flow better will give you a couple horse power while giving you a nicer sound and maybe a couple mpgs of you drive moderately. Would you consider this accurate?

[@saauuzza]

Bizzenn1976 maybe

[@acpoodle]

This is a performance exhaust on a vtec engine, surely it makes more sense to test a range that is relevant to the performance - ie when the thing is actually on cam, as this is what the exhaust should be designed to do....

[@EngineeringExplained]

No vtec.

[@Joshf93.]

you should do an ECU remap for your next video! will be interesting to see what hp gains you could get from your now better flow exhaust system and a remap!

[@iwrotefuck]

so 2% sounds kind of small for something that would cost say $1000 or however much. would you say its worth the money or are there more cost effective things that could be done instead?

[@EngineeringExplained]

+iwrotefuck This catback is something like $200. Removing unnecessary weight is the most cost effective thing you can do.

[@IRDC305]

and i think the more stock horsepower, the higher the increase after the exhaust installation

[@dhairt7772]

+Engineering Explained +iwrotefuck I thought the point of a higher quality exhaust was to aid other mods such as a supercharger as theres less exhaust stresses and stuff so you can get higher HP, without making any mods that require increased airflow there will be very little improvement, some of which just might be due to the limit of accuracy of the measurement device

[@p3l1k44n1]

+iwrotefuck When your car is from the 60's and it barely has 70hp.. You'll kinda want to grab that one extra hp if you can. Cause that's realisticly all you can get for a cheap mod. If i go all out on this engine, i'll probably go to the 100hp mark before the engine starts being unreliable.

[@david6pac]

+Dhair T its just for very slight increases which is barely noticeable but you are correct in terms of aiding other mods. its like putting a short ram intake in your engine. gives you a very short burst of boost (and i mean short) and unfortunately most people who only put an intake (which cost anywhere between 120 - close to 300 bucks) dont know this fact. but i mean if you put these mods just for sound then it will def do that for you! most ppl who look for big gains needs to spend thousands of dollars

[@kodez79]

On low RPM there will not be enough exhaust moving trough the pipes to give a significant airflow resistance. Testing 5k to 7k in 3rd gear would be easier and more relevant. When you add a turbo, testing low revs will be relevant.

[@CozmoBomb]

Love this series man. Keep it up.

[@josefilho8456]

I think you really should get the car into the dyno. With the video we know that in acceleration, the values are not that different. But how much would that represent in HP? And them it would come the question, is it worth to spend $$ to "earn some HPs" and have almost the same performance? Just and engineer to engineer tip. Keep doing your excelent work!

[@Phamtastic]

The most restrictive area is in the header design on the B18. So it's expected that a catback won't shine unless you get a header matched up to it.

[@cmichaeloutube]

Hey, that was a great video and a good systematic way of evaluating the acceleration benefits of practically any modification. I know this would be very loud but have you done any tests WITHOUT the catback exhaust, and which would actually answer the question you pose in the title ;-) ?

[@tonysoprano4624]

Do an update on your sti!

[@onetimeracas5972]

The categorical RPM range falls to that low area because even standard cars have a bitching moment with the shifting between 20-40. Make that amount 35 and up and this improves significantly. Like you say, it makes sense and that catback exhaust could feel versa another. May look into this further to gather a tad more..

[@Damianmazoti]

Subscribed for the integra have an 97 LS myself

[@onefastcyclist]

How did you choose a cat-back system for an automobile that spins 4,000 rpm traveling at 80mph on an interstate? Did you make a [ Loud droning at sustain speed vs performance gain comparison ] when choosing the components?

[@thesniperofcs]

no they don't, stickers do

[@mod3rnwarrior34]

Each sticker adds about 5hp I would say 😂

[@vhonalbertastorga]

from the definition of "catback", even without doing cat delete, you can still have performance gains by having bigger exhaust pipe . Another advantage would be it will sound better 👍

[@zombieqtr]

LONG TUBE HEADERS, THEN CATBACK,cast iron manifold with catback haha

[@h5ibluntman]

If you can next do a comparison to straight pipe vs cat back. Now it can be straight pipe with cat, without cat, also with resonator and without. because there is a lot of aruments that going straight pipe will make you lose power. Even though you are making it eaiser for your engine to breath

[@ReefAdvicer]

Yes you do lose hp and torque with out enough backpressure because it helps with harmonics and pulses in the header which help everything run more smooth

[@EngineeringExplained]

ReefAdvicer Back pressure is not desired. Exhaust velocity is so that proper scavenging occurs. Back pressure is a result of a restriction, meaning you could be making more power if it did not exist.

[@h5ibluntman]

exactly

[@ZEN824]

+Blunt Man cat back is even better than a straight pipe. exhaust actually creates a pressure wave, when at the end of the pipe, the wave is going back to the engine. but with cat back, it absorbs the wave and it actually flows better as the exhaust gas flow faster bcause the cat back has a pipe with holes that is wrap with fiber.. the holes traps some air as the velocity increases and that trapped air acts like a lube. same principle as the hydroplaning of a car tire in the rain.

[@dtweed87]

Hey, I imagine this has been mentioned already, noticed that your vehicle was not up to temperature when you were doing these tests on the 0-40 2nd gear tests from Catback 1 - Catback 2 there is a noticeable difference on where your temperature gauge is pointed. I could also then assume that the tyres were not at temperature and therefore you were not getting a consistent grip on all three tests & the engine was not at peak operating levels. Although I doubt the difference would be high it is important to have a fair scientific test, or at least highlight what makes a test unfair.

[@TheRealBmanswan]

If I remember correctly a catback exhaust will help lower your engine temperature since the heat can leave the engine faster and doesn't build up where a catalytic converter normally would be.

[@goku546686]

what about turbo back exhaust? what is best with a turbo engine? any suggested products to give the best results?

[@Hind135]

Enjoying this project, keep it up!

[@rudedogii]

Great video. I have been telling people for years that all that Hi Performance stuff is nice but only if your'e driving fast. The same goes for Cold Air intakes. They can cost from $200-$300 dollars for a plastic pipe and and hi-flow filter with power gains at 4,000rpm. I rarley get my truck to rev that high so I stick to the factory intake and save my money. It's my daly driver not a race car.

[@EngineeringExplained]

I agree!

[@MrIrrepressible]

Engineering Explained what mods would be best to improve the performance at low rpms, ie everyday driving speed?

[@RyuusanFT86]

In Short- more high end power. For the Integra with a B18B like Him and I, you don't have a lot of top end. Where you'd definitely notice is around 5k in 4th gear.

[@dannyozuna]

What exhaust cat back was used? What type of system did it use manage sound? Little secret they them, the ones with the secrets don't tell is that harmonics are used on the more expensive exhaust that's why they cost more. The other cheaper ones use deflection, or a material to dampen to the sound.

[@jeremieorange7887]

Thanks for sharing this knowledge acquired by testing / experiencing things on your own ! Great work done here ! Keep going on make us those videos :) I'd also like to thank you for ealier videos (**everything you need to know about cars** explained !) it helped me a lot in my restoration project of my 94 1g dsm ! If i can you help by any way I can, let me know (FYI I'm an experienced IT developer ;))

[@Logix727]

I just want you to test the effects on MPG this is much more widely debated than performance gains.

[@benh4222]

For better accuracy you could do your tests up a steep hill. It would be nice if you could performed the test to the rev limiter too.

[@eduardozarate8723]

Any updates on the Acura? I recommend braking down the engine an explaining what role the major components play. And boring put the engine or even swapping piston rods and pistons for lighter ones.

[@kevinocta9716]

Edit: You noticed this too! I just was a bit hasty I guess. :D Just a quick thought: we are measuring pretty small differences, and you're times appear to be limited to 1/30th of a second (i.e. limited to the frame rate of the filming camera). With fractions of seconds mattering in this test I would only go with the averages, not bests. Just because those could be at least partially swayed by the frame rate at which you are measuring. And when the differences are 1-3% (1/100 to 3/100) and you can only get 1/30th per second accuracy, might that influence the results a bit?

[@allankobanawa9204]

Hi nice video as always! Was this cat back test without the weight or did u put the weight back? How did it compare against the weight reduction test? I reckon those figures would be more precise on how the catback exhaust improves performance. Thanks!

[@EngineeringExplained]

Allan Kobanawa All tests will be cumulative, so this is with the reduced weight (both tests).

[@CynRacing]

Engineering Explained You should install Poly engine mounts, I'd like to see how this effects acceleration. It would also be nice to understand the effects from a Engineering perspective. Since this is just a project car I'd say go for full racing engine mounts. If not, fast road mounts may be better for daily drivability. However, considering you're doing all these tests from 0mph and counting from 20mph, I can't imagine the engine mounts would make much of an improvement to acceleration, as apposed to slamming on the gas, as this is where i believe the engine mounts reduce the amount of throw of the engine, allowing the engine to put the power down quicker. Maybe I answered my own question, so maybe it won't effect acceleration using variables used in this test, maybe device another test where for e.g. you test acceleration using WOT only from 3000rpm.

[@EngineeringExplained]

Engine mounts are unlikely to have any effect on acceleration (unless of course, they have a significantly different weight).

[@Highfiveletsride]

Engineering Explained in fwd stiffer mounts 100 percent increase acceleration. Decreases wheel hop and keeps the power to the ground.

[@ItsShenaniganz]

Project integra vids are totes my fav.

[@Loyal_Honda_Fan]

thanks a lot sir you answered all of my questions you're a master mechanic!

[@donkyuhbuhts540]

Yet another awesome vid!

[@nos1000100]

i have noticed that in the install video that you left the stock cat and headers, Do you plan on changing them as well? Im pretty sure that iff all your pipes are the same size and from the same place that made them, the preformance will show better results

[@EngineeringExplained]

andrew anderson At some point, I may end up changing them. I do indeed have an aftermarket header sitting around. :)

[@mrsantosjon]

What about catback system with a muffler silencer? Does it decrease performance? I feel like adding the silencer the acceleration feels more responsive.

[@TiEx]

I was thinking about the whiteboard in the background. How about filling it in "in sync" with the video. Like after the first pull with stock and catback, the bord would have that info filled in, but no more.. The way you do it now made me see the results long before you told me about it.. Just a personal opinion.. But it would be more "exciting" for me anyway ;) Great job btw, Whats the next thing you will change?

[@EngineeringExplained]

That's what I did with the previous video - I was a bit rushed in getting this one out, as I've been traveling the past three weeks, so I made some sacrifices. Not sure what the next thing I will change will be, need to organize my thoughts. :)

[@greeneking77]

Will an aftermarket catback exhaust improve fuel economy if I drive conservatively ?

[@spiritbuu]

What about fuel economy? Would a high-flow Cat-Converter and Muffler and new exhaust pipe without any built up gunk overtime result in easier flow path for the exhaust gases resulting in less resistance which means better fuel economy?

[@MrSoulisTG]

Find an open quiet road... and try 4th gear pulls from ~2000rpm to rpm limiter or slightly lower... Like a dyno... but in real road conditions... That way you will have tested all (low,medium,high rpms)... on around 1:1 gear ratio...

[@Xerdoz]

You should've done a test with some added weight since the catback system is lighter than the stock one. So you could've just tested if the pipe alone makes a difference (increase or decrease the power).

[@R32-x9g]

Xerdoz the weight aspect is part of the test though

[@Humance]

I suggest 40-70 mph in 4° or 5° gear.

[@m.pietro9087]

It would be awesome if we could see the difference in a 1/4 mile test.

[@cynicalatbest6934]

So why did you say -0.729 instead of -0.719 in between 4:30 and 5:00? Was it just a mistake?

[@Chev_chevo]

Think of the performance exhaust as a gateway to add more without restriction, you'll never get what you fully want without getting rid of that stock. (04 g35 with invidia exhaust + Invidia pipes + tuned) more to come. Went from 265-330hp. Btw I had a bad aftermarket exhaust before installations.

[@datkidelmo]

I'm looking for tips to increase power on my 2011 g37x..... I have a stillen catback and was considering purchasing HFCs and getting a tune. I have mixed opinions about intakes though because I hear that the stock intake is what's best optimized for the car. I wanna make more power without sacrificing efficiency through the power band any suggestions?

[@Hunedpcl7]

Can't wait for the next Project Integra vid. Do you already know what the next upgrade and test will be?

[@coreystaunton4954]

Just wondering if you take into account how much fuel you have in the car when you do these test as that can change the results also. Just a thought.

[@ira7589]

what are the factors affecting the horsepower ? Can you list down the characteristic of a few types of exhaust system

[@agl_bst6376]

So is an axle back just for sound and of no consequence to power or acceleration, so much so that it wouldnt even require a retune?

[@youmaster21]

Can you explain why removing cat sometimes you will end loosing top speed on stock cars, Why some exhaust systems are better for acceleration and others are better for top speed? because theoretically if a car accelerates better it should do more speed, but that´s not the case

[@urface12343]

youmaster21 that’s like awd vs. rwd. AWD gives you better launches but inhibits top speed. Rwd gives you worse launches but gives you greater too speed. Same with downforce

[@BlakeHarvey903]

i have always been taught to NOT lug the motor. Keep the RPM's up until you are cruising. If you're losing speed due to a steep hill make the car downshift. In this case you shouldn't be in the 3rd gear going 20mph lol

[@MorganBrown]

bro, all these years and I had no clue you were tuner!

[@Big_LosF]

awesome video. very informative, thx an keep em coming.

[@lukeiannello6190]

Is your engine running cold, or is that just where the gauge settles?

[@christosvasiliou219]

in an audi tt with 260-280 hp its gonna make a significant difference ?! 10 horses up or not

[@cobra454tim]

I'd like you to do this with your Subaru, I own a 2013 Legacy 3.6 R and wonder if the DAVC system would benefit more from an exhaust system?

[@robjespitia4538]

Love your videos man

[@Rynopb]

did you calculate the weight of the exhausts. i might have missed it if you mentioned it

[@Mutt83GC]

The increased piping size throws of the balance and shift your torque band to higher RPM. That's one of the reasons your not getting a increase in power.

[@ryanfay1]

Taching it out to redline is going to reveal the biggest performance gains over stock. Go further!

[@ripkobexnip3719]

im thinking of buying a 750$magnaflow exhust sytem will it be worth it and gain power i alrrady have a cold air intake

[@urface12343]

kush gottheju1ce2k with the cold air I take the results would be a lot more substantial over a stock motor but you won’t notice much compared to just a cai

[@datpmf]

Hi Jason! I was wondering if you have an opinion on why do crankshafts use plain bearings instead of roller bearings?

[@matthewkinney5474]

Kind of 8 years late to the party but this is because the crankshaft bearings are supported by the oil, so they have even less wear/drag then a roller bearing.

[@abdelrahmanalhammadi6705]

after installing the catback . should you tune to get the increased power of the catback. what i mean is installing a catbavk without tuning is just for the sound right. no power will be gained if i did not tune?

[@juniorperez2472]

love your videos, please do video if removing cats increases hp with proof

[@jerri0401]

Could you say, because of the larger diameter the exhaust doesnt work that good at lower rpm because of a lack of "vacuum" that pulls the exhaus gases out ( like you explained in the catback video) ?

[@EngineeringExplained]

Yep, less scavenging.

[@techtifoso]

Catback on a turbo is far more effective use of $$ than catback on NA engine. Also one brand may suck, each should be dynoed

[@mjohnston0925831]

I have a 2017 gti fastest gti and golf r are running stock exhaust. Years ago Hondas gained from catback. Newer turbos gain from a downpipe very little to no gain from catback. Just sound.

[@mjohnston0925831]

Not just Honda's just in general 90's early 2000's vehicles gained from catback. Newer cars have do much more R&D.

[@MostDubs]

is this after weight reduction? would be interesting to see one pre weight reduction and pre cat vs after. Any guess as to what kind of gains you would be getting in total? about 5.5%?

[@EngineeringExplained]

Second Shooter Yes, around 6%.

[@TheGaginator]

Super cool video!

[@WORLD-OF-MERLIN]

I wish someone would just simply do a before and after dyno on it like a video I made on my channel for a supercharger.

[@BlueDroneBlues]

Seems more about looking cool with bigger exhausts. Unless your doing timing tests. The results are barely noticeable. Unless the default setup is shot or pretty poor letting gas fumes and air out. Then the difference will be much bigger. 4% increase tops in most cases. Who really cares I guess whatever floats your boat? Good video thanks for comparisons.

[@danielsifuentes8657]

I saw the vid from cold air intake and now this one. Would it be safe to say that since the cold air intake is slower on low rpm's and the catback is faster in low rpm's if you were to use both you would have better results usong them together vs either or?

[@michaelhernandez7915]

so what I got out of this video is that an exhaust does nothing for your car as an "everyday driver" at low RPMS? Only get a new exhaust if you intend on hitting high RPMS at higher speeds which you're only able to do at a racetrack without getting at ticket. Would you recommend getting an exhaust to someone who doesnt race, but wants their car to go faster? Is an exhaust the answer?

[@jonsauce]

+Michael Hernandez booost

[@TheShadeManGuitar]

to me the purpose for changing exhaust is to get a better sound not to much of a performance gain

[@nblax41]

Car should be wicked once it's complete!

[@bob-a-louannamaria7960]

This is one vehicle. Obviously cat backs vary vehicle to vehicle and engine to engine. It all depends on hose restrictive the stock exhaust is compared to the cat back. I’ve put cat back exhausts on some vehicles and felt and measured zero change, and some are night and day difference. Usually smaller engines don’t have much restriction stock due to less exhaust output and larger engines tend to respond better. Unless of course it’s a more modeler performance model from the factory with an optimum exhaust system and tune.

[@PurpleHeartVR]

What about stock mufflers that don't have any airflow restriction like the Cobalt SS/TC?