I am filled with regret !!

aeonixx

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I just put the MAperformance Cat bac Quad tip on my car with the street muffler and its F*&%$$$ Great! I adjusted the tune slightly and this baby is a legitimate fast car now that purrs like a kitten but has a bit of a roar when I take off. You dont want to just cut your muffler off, you need a bit of back pressure to make things sound and run a bit smoother.





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Old George

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My comments were addressed to those who have exhaust 3 according to your classification.
When you have an SI with an air intake, a charge pipe, a down pipe and modifications in the ECU,
a fine dyno tune...installing an exhaust at $ 1000 to gain 3 or 5 hp, is , in my opinion , an
unnecessary expense, if not making a lot of noise.( see Jayceegee )
But that's my opinion, you have yours and it is correct.
Some will say: I gained 10, 15, 20hp.. Put the car on a dyno and we will see.
Everyone does what they want with their money.
 

ne0guri

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I have to agree with you. I left my intake, down-pipe and mid-pipe stock and added a aFe Takeda 3" to 2--1/2 Cat-back performance exhaust and definitely felt a performance boost over the stock exhaust, although several members of this forum say that there are no performance benefits to adding a performance exhaust. aFe claims 10 whp, some say that number is BS, really no way to know without putting it on a dyno, but at $200/hr it's not really worth finding out
Yeah, not sure if it’s a placebo effect or the extra noise making the car feel faster? But I feel the same way with my 27Won system. I definitely feel an extra oomph vs before installing the system.

But I’m excited to see the gains from the downpipe once I get that installed.
 

ladysi

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I must have a rare opinion judging by most on these forums, but I like the muted sound of the stock si exhaust. I can hear the engine better and the boost spool up. I also appreciate that I have a sleeper element... my car may be quiet, but she is not slow. It is also appreciated by my girlfriend and other passengers, I have heard positive feedback from multiple folk - they expected the car to be obnoxiously loud given how it looks, and they have noted that they were pleasantly surprised. I guess they are used to hearing the scrape pipes + strung out vtec rpms of previous gens.

Also, it makes long road trips less of a strain on the ears given some of the very loud drones I have heard on other cars in the class. Props to Honda for not piping engine noises into the cockpit or playing fake sounds through the speakers.

Anecdote: I also like the hdmi exhaust shape. It is different and rather unique among all the other makes and models out there. It also compliments the aesthetics of my taillights and rear led bumper lights. Futuristic and cyberpunk, but not so overboard that it is comical.
 

amirza786

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I must have a rare opinion judging by most on these forums, but I like the muted sound of the stock si exhaust. I can hear the engine better and the boost spool up. I also appreciate that I have a sleeper element... my car may be quiet, but she is not slow. It is also appreciated by my girlfriend and other passengers, I have heard positive feedback from multiple folk - they expected the car to be obnoxiously loud given how it looks, and they have noted that they were pleasantly surprised. I guess they are used to hearing the scrape pipes + strung out vtec rpms of previous gens.

Also, it makes long road trips less of a strain on the ears given some of the very loud drones I have heard on other cars in the class. Props to Honda for not piping engine noises into the cockpit or playing fake sounds through the speakers.

Anecdote: I also like the hdmi exhaust shape. It is different and rather unique among all the other makes and models out there. It also compliments the aesthetics of my taillights and rear led bumper lights. Futuristic and cyberpunk, but not so overboard that it is comical.
Like you, I like it quiet as well! Well, as quiet as a small car can be, that is. Unfortunately the current exhaust I've installed is slightly louder than the stock, but thankfully not by much. aFe told me I can quiet it down by adding a silencer without losing performance or warranty. I'll think about it
 

Old George

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It is the down pipe that gives the largest share of the gain, especially when the rest
of the system is already very good.
It is just a small 1.5 l engine that doesn't exceed 6500 rpm, so the gas flow is not that important.
The K 20 was 2.0 l and running at over 8000 rpm , the pipe was 2.5 in and there was only
one resonnator at the back.
The 2.4 l has the same exhaust and it went up at 7200 rpm.
I have not changed my mind but you are free to keep yours.
Noise probably has an influence on the perception of power and speed.
 

COOL COUPE

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Borla 27 pounds S tupe exhaust cat back 89.90 Decibals ... I got to have it ... cost is an issue but it's air craft quality steel. S type brand speeds up exhaust flow to enhance performance ... Only available on the Coupe ... which I have ...
 

amirza786

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It is the down pipe that gives the largest share of the gain, especially when the rest
of the system is already very good.
It is just a small 1.5 l engine that doesn't exceed 6500 rpm, so the gas flow is not that important.
The K 20 was 2.0 l and running at over 8000 rpm , the pipe was 2.5 in and there was only
one resonnator at the back.
The 2.4 l has the same exhaust and it went up at 7200 rpm.
I have not changed my mind but you are free to keep yours.
Noise probably has an influence on the perception of power and speed.
You are correct, Downpipe and Midpipe would give you the most power gains over a Cat-back exhaust, but there was definitely some performance gain in putting in the aFe Stainless Steel Cat-Back. This is unscientific, but on stock exhaust, TSP Stage 1 tune (map 1) I did a 0-60 run @ 6.5 seconds.After installing performance Cat-back, TSP Stage 1 (map 1), Amsoil Synchromesh MT fluid, Acuity Shifter Rocker upgrade, on the same stretch of road 0-60 @ 6.3 1/2. I mentioned the other upgrades as these may have also contributed to the better time

I just want to make it clear I am not advocating for you to change out the stock exhaust. I spent about $800 (it was on sale, 0 percent financing) on this exhaust and for a one in a half second gain was it worth it? In hindsight I probably would have just stuck with stock, but now that I have it installed I am happy with it and am going to keep it
 

Old George

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Amirza 786
I have some questions; it is by professional deformation. Even if I haven't taught physics
for almost twenty years,I' ve kept my scientific and logic mind.
You tell me you gained 0,15 s: I believe you, but were the conditions the same?
(air temp, ground temp, humidity, wind...)
All this variables can influence the results.
How much will you spend to install a silencer?
I don' t believe in a silencer that doesn' t cause any restrictions.
If it reduces sound, it necessarily slow down the gas vein.
You are happy with your mods, I am happy for you , I am sincere.
I wish you to take full advantage of your SI.
If I lived in California or others states where temperatures are high or very high,
I would have put a larger intercooler like the Mishimoto.
I thought I would do it, but, here, very hot days are quite rare,
 

amirza786

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Amirza 786
I have some questions; it is by professional deformation. Even if I haven't taught physics
for almost twenty years,I' ve kept my scientific and logic mind.
You tell me you gained 0,15 s: I believe you, but were the conditions the same?
(air temp, ground temp, humidity, wind...)
All this variables can influence the results.
How much will you spend to install a silencer?
I don' t believe in a silencer that doesn' t cause any restrictions.
If it reduces sound, it necessarily slow down the gas vein.
You are happy with your mods, I am happy for you , I am sincere.
I wish you to take full advantage of your SI.
If I lived in California or others states where temperatures are high or very high,
I would have put a larger intercooler like the Mishimoto.
I thought I would do it, but, here, very hot days are quite rare,
As I mentioned in my previous post, it was an unscientific observation. Road conditions were similar, but I cannot argue with a physics teacher!

A silencer will cost $25, and according to aFe (the manufacturer) it won't affect performance. But I really don't need a silencer as this exhaust is only slightly louder than stock, as it has smaller mufflers than the originals.

Have a great day sir, and thanks for sharing your knowledge and experience
 
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James3spearchucker

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Amirza 786
I have some questions; it is by professional deformation. Even if I haven't taught physics
for almost twenty years,I' ve kept my scientific and logic mind.
You tell me you gained 0,15 s: I believe you, but were the conditions the same?
(air temp, ground temp, humidity, wind...)
All this variables can influence the results.
How much will you spend to install a silencer?
I don' t believe in a silencer that doesn' t cause any restrictions.
If it reduces sound, it necessarily slow down the gas vein.
You are happy with your mods, I am happy for you , I am sincere.
I wish you to take full advantage of your SI.
If I lived in California or others states where temperatures are high or very high,
I would have put a larger intercooler like the Mishimoto.
I thought I would do it, but, here, very hot days are quite rare,
You said that if a muffler is to be quieter, then the gas must be slowed down. This is not true because there are various technologies employed in muffler construction. In straight through designs, especially long mufflers, the speed of gases increases at certain RPM even though the sound is measurably attenuated, including low frequencies. The perforated inner tube reduces drag, thus producing more power than a straight, steel pipe. The biggest limiter to total flow is the diameter of your pipes and mufflers, with both power and sound being affected.
 

Old George

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The design and construction of an exhaust system ( except the down pipe ) is complex
because it involves both fluid dynamics and acoustics.
It is therefore empirically that most manufacturers do this.
They cut, bend,assemble and weld the pipes with the muflers, te resonators....it is sometimes
more or less successful, but not always, depending on the engines and I am not talking about aesthetics.
You can say, believe, buy what you want, that's what freedom is all about.
I believe in 2 principes:
- the sonometer that measures the increase in decibels
- the dyno that measures the increase ( or loss ) of power.
Everything else is just assumptions with no real basis.
 

James3spearchucker

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Thats like saying that you have to send a sample of the soup to the laboratory to find out how much salt is in it. You just taste it!!!! Yeah some people can only use measurements. Most people can feel acceleration and count the seconds. Also most people can hear the tone. The human ear is very very sensitive and our brains quite capable. Despite the fact that there are not extensive A/B dyno and SPL comparisons between exhausts on the market, the evidence that high power can be had quietly is proven by the SI and Type R Civic models. Both are designed to flow well and sound smooth. Milltek, as a manufacturer, specializes in high output systems and tame sounds. Supersprint and Borla are next. These companies do extensive testing using dynos and SPL, RTA's.
 

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