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

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

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

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

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...

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.

Love this series man. Keep it up.

Great experiment! Always worth watching your tests! Congrats !

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

I like the methodical approach you are taking with this.

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.

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

Enjoying this project, keep it up!

I'd like to see this after installing a header

Yet another awesome vid!

Excellent. Showing you dont need fancy dynos to baseline and track improvements.

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.

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

Love your videos man

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

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!

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!

Subscribed for the integra have an 97 LS myself

Cool video man

Super cool video!

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

Do an update on your sti!

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 ;))

Good points dude

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 ;-) ?

Project integra vids are totes my fav.

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

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?

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 ;)

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 😄.

Proper Engineer!

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

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...)

@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! :)

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

excellent!

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

planning on any conversions? engine,drivetrain etc?

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.

this guy is a real g

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!

I suggest 40-70 mph in 4° or 5° gear.

Please do a video for DiY TFT screen /dash for speed and other engine parameters

since the back pressure air and fumes exist faster a flow more freely i belive straight pipes "in some cases can" give you more power

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.

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?

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.

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.

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.

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

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

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..

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!

do this video again after a tune

Next video pleaseee

Can you do a test with the cold air intake

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

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

You should do all these tests again with a turbocharged engine

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

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

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....

Should change your tires to semi slicks next

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?

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?

Did the fuel economy increased?

Car should be wicked once it's complete!

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

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!

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

does resonator delete cause power loss? Can you do a video for that please

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.

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.

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?

Did you see a mpg gain?

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

Will you do headers next?

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.

Do an open header, or test pipe run... :)

no they don't, stickers do

Could we see new cams in the car or something with the engine.

But what about a remap with and without the mods?

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

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

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.

do you have a test between aftermarket 4-2-1 headers versus stock ?

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...

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.

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

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

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).

What about turbocharged engines ?

Wait, how can the AVERAGE be a lower time than the "Best" for several datapoints of the catback condition?

when do you take the ice bucket challenge, that brian sent you? :D

What size diameter is the catback compares to the stock?