Straight pipes, back pressure and cold air intake
#1
Straight pipes, back pressure and cold air intake
Hey all,
I have recently installed straight pipes on my 2010 C300 and it sounds mad.
Question is, i have heard that since the exhaust gases are flowing more freely (see backpressure) , i would have to flash my ecu to get the fuel to air ratio back on track and instal a cold air intake too.
Is this true? will the ecu, as it is stock, be able to regulate the fuel to air mix already without having to do anything?
thanks for replies
I have recently installed straight pipes on my 2010 C300 and it sounds mad.
Question is, i have heard that since the exhaust gases are flowing more freely (see backpressure) , i would have to flash my ecu to get the fuel to air ratio back on track and instal a cold air intake too.
Is this true? will the ecu, as it is stock, be able to regulate the fuel to air mix already without having to do anything?
thanks for replies
#2
Hey all,
I have recently installed straight pipes on my 2010 C300 and it sounds mad.
Question is, i have heard that since the exhaust gases are flowing more freely (see backpressure) , i would have to flash my ecu to get the fuel to air ratio back on track and instal a cold air intake too.
Is this true? will the ecu, as it is stock, be able to regulate the fuel to air mix already without having to do anything?
thanks for replies
I have recently installed straight pipes on my 2010 C300 and it sounds mad.
Question is, i have heard that since the exhaust gases are flowing more freely (see backpressure) , i would have to flash my ecu to get the fuel to air ratio back on track and instal a cold air intake too.
Is this true? will the ecu, as it is stock, be able to regulate the fuel to air mix already without having to do anything?
thanks for replies
#3
The ecu should make the adjustments needed. When you say straight pipes, did you remove the cats as well? If so, that may require a tune, but merely removing the muffler/s shouldn't affect your afr. The increased airflow via intakes/exhaust is too minor to "need" a tune.
I hope you didnt misunderstand me. My mufflers are still up. What was removed was the resonator.
#5
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2008 C300 4MATIC
Basically, you did an x-pipe? From what I have read on the forums, it does not change anything that would relate to the engine. The only difference it makes is the sound, which is awesome.
#6
yes. Basically thats what i did but instead of it being an X, its two straigh pipes joining the cats to the mufflers.
#7
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#12
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If you don't want your car smell like a lawn mower and 2 cycle oil install oil catch can.
#13
#14
With this said, i would really apreciate it if somebody could give me a hand with figuring out if having the exhaust in a "true dual" manner has any pros and cons over having the X-pipe. ( i asked this since, upon looking through the resonator, i saw an X-patern, which would explain why people decide to put x-pipes, it follows how the stock exhaust was designed to flow but without the silencing effect)
#15
Senior Member
I know its super late, but would this video on a V6 mustang exhaust help to differentiate x pipe from H pipe? I'm not quite sure what to make of the flow animations, but looks pretty interesting nonetheless.
#16
Super Member
Here is my two cents...
I did the resonator to xpipe first. It was pretty good, doesn't really kick in until 4k+ rpms. After having that on for a few months, I wanted something more. A few friends were getting ready to get muffler delete and I thought "sure, why not". Getting my mufflers delete plus having the xpipe makes my sounds so perfect. Its such an exotic sound (even with all my other friend's car around ie bmw audi infinty sti evo...). I have some videos on my youtube channel if you would to see.
As for the cats, I'm always going to keep those in because I dont want to mess around with legal stuff.
EDIT: as for the back pressure, there is some but not too much. Normally only happens when I hold a gear and slow down. Sometimes I'll hear a loud pop but its random.
I did the resonator to xpipe first. It was pretty good, doesn't really kick in until 4k+ rpms. After having that on for a few months, I wanted something more. A few friends were getting ready to get muffler delete and I thought "sure, why not". Getting my mufflers delete plus having the xpipe makes my sounds so perfect. Its such an exotic sound (even with all my other friend's car around ie bmw audi infinty sti evo...). I have some videos on my youtube channel if you would to see.
As for the cats, I'm always going to keep those in because I dont want to mess around with legal stuff.
EDIT: as for the back pressure, there is some but not too much. Normally only happens when I hold a gear and slow down. Sometimes I'll hear a loud pop but its random.
Last edited by ickdeep; 06-29-2015 at 03:13 AM.
#17
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2010 C350 Sport
I know its super late, but would this video on a V6 mustang exhaust help to differentiate x pipe from H pipe? I'm not quite sure what to make of the flow animations, but looks pretty interesting nonetheless.
https://www.youtube.com/watch?v=2crCWF5cmLk
https://www.youtube.com/watch?v=2crCWF5cmLk
See how on the high pressure flow with the H-pipe there is a concentration of gas in the bridge? This high pressure region effectively serves as a dam preventing the free flowing gases from freely passing through, but it does not stop sound waves, however; because of the higher density of gas in the high pressure bridge the sound waves will be attenuated more.
The X-pipe does not have a bridge but instead a smooth transition crossover which prevents the formation of a high pressure region. This allows the gases and sound waves to mix more freely and evenly.
As for what will happen at what RPM with what kind of sound, I have no experience so I have no idea. Hope this helps somewhat.
Here is my two cents...
I did the resonator to xpipe first. It was pretty good, doesn't really kick in until 4k+ rpms. After having that on for a few months, I wanted something more. A few friends were getting ready to get muffler delete and I thought "sure, why not". Getting my mufflers delete plus having the xpipe makes my sounds so perfect. Its such an exotic sound (even with all my other friend's car around ie bmw audi infinty sti evo...). I have some videos on my youtube channel if you would to see.
As for the cats, I'm always going to keep those in because I dont want to mess around with legal stuff.
https://www.youtube.com/watch?v=8xcWhC6SFXM
EDIT: as for the back pressure, there is some but not too much. Normally only happens when I hold a gear and slow down. Sometimes I'll hear a loud pop but its random.
I did the resonator to xpipe first. It was pretty good, doesn't really kick in until 4k+ rpms. After having that on for a few months, I wanted something more. A few friends were getting ready to get muffler delete and I thought "sure, why not". Getting my mufflers delete plus having the xpipe makes my sounds so perfect. Its such an exotic sound (even with all my other friend's car around ie bmw audi infinty sti evo...). I have some videos on my youtube channel if you would to see.
As for the cats, I'm always going to keep those in because I dont want to mess around with legal stuff.
https://www.youtube.com/watch?v=8xcWhC6SFXM
EDIT: as for the back pressure, there is some but not too much. Normally only happens when I hold a gear and slow down. Sometimes I'll hear a loud pop but its random.
The way I had it the drone was unbearable cruising at 1500 rpms but surprisingly no drone on the highway. There was definitely a noticeable affect from the lack of back pressure too. In your case you have the resonator, which helps; in my case there was nothing and certain gear shifts became more sluggish and acceleration took a hit.
I'm sure the ECU would've straightened it out but after the Magnaflow's went on everything was back to normal. So the myth with back pressure is partial and subjective to the individuals liking.
#18
Super Member
So you kept the stock resonator, added an X-pipe after it, then deleted your mufflers? Sounds very nice. I have my resonator completely replaced with an X-pipe and for a day (after I cut my mufflers out to be replaced with a pair of Magnaflow 10416's) I had straight pipes after the cats. I did not like it. Yours sounds a lot more refined which, I'm assuming, is because of the resonator helping to manage the sound waves.
The way I had it the drone was unbearable cruising at 1500 rpms but surprisingly no drone on the highway. There was definitely a noticeable affect from the lack of back pressure too. In your case you have the resonator, which helps; in my case there was nothing and certain gear shifts became more sluggish and acceleration took a hit.
I'm sure the ECU would've straightened it out but after the Magnaflow's went on everything was back to normal. So the myth with back pressure is partial and subjective to the individuals liking.
The way I had it the drone was unbearable cruising at 1500 rpms but surprisingly no drone on the highway. There was definitely a noticeable affect from the lack of back pressure too. In your case you have the resonator, which helps; in my case there was nothing and certain gear shifts became more sluggish and acceleration took a hit.
I'm sure the ECU would've straightened it out but after the Magnaflow's went on everything was back to normal. So the myth with back pressure is partial and subjective to the individuals liking.
#19
Senior Member
I only have academic experience with fluid dynamics so I'm sure someone else will be able to elaborate more. The main difference is the H-pipe mainly serves to mix sound waves whereas the X-pipe mixes both sound waves and exhaust gases. Both will sound differently though.
See how on the high pressure flow with the H-pipe there is a concentration of gas in the bridge? This high pressure region effectively serves as a dam preventing the free flowing gases from freely passing through, but it does not stop sound waves, however; because of the higher density of gas in the high pressure bridge the sound waves will be attenuated more.
The X-pipe does not have a bridge but instead a smooth transition crossover which prevents the formation of a high pressure region. This allows the gases and sound waves to mix more freely and evenly.
As for what will happen at what RPM with what kind of sound, I have no experience so I have no idea. Hope this helps somewhat.
See how on the high pressure flow with the H-pipe there is a concentration of gas in the bridge? This high pressure region effectively serves as a dam preventing the free flowing gases from freely passing through, but it does not stop sound waves, however; because of the higher density of gas in the high pressure bridge the sound waves will be attenuated more.
The X-pipe does not have a bridge but instead a smooth transition crossover which prevents the formation of a high pressure region. This allows the gases and sound waves to mix more freely and evenly.
As for what will happen at what RPM with what kind of sound, I have no experience so I have no idea. Hope this helps somewhat.
I'll have to go dig up an old thread about how back pressure will affect performance in our cars, or if the difference is even noticeable. I'll probably just spend a few hours googling and reading up on backpressure and exhaust performance in general lol
Thanks for the insight
#20
Junior Member
Here is my two cents...
I did the resonator to xpipe first. It was pretty good, doesn't really kick in until 4k+ rpms. After having that on for a few months, I wanted something more. A few friends were getting ready to get muffler delete and I thought "sure, why not". Getting my mufflers delete plus having the xpipe makes my sounds so perfect. Its such an exotic sound (even with all my other friend's car around ie bmw audi infinty sti evo...). I have some videos on my youtube channel if you would to see.
As for the cats, I'm always going to keep those in because I dont want to mess around with legal stuff.
Mercedes Benz C300 Muffler Delete & X-pipe, first start + take off - YouTube
EDIT: as for the back pressure, there is some but not too much. Normally only happens when I hold a gear and slow down. Sometimes I'll hear a loud pop but its random.
I did the resonator to xpipe first. It was pretty good, doesn't really kick in until 4k+ rpms. After having that on for a few months, I wanted something more. A few friends were getting ready to get muffler delete and I thought "sure, why not". Getting my mufflers delete plus having the xpipe makes my sounds so perfect. Its such an exotic sound (even with all my other friend's car around ie bmw audi infinty sti evo...). I have some videos on my youtube channel if you would to see.
As for the cats, I'm always going to keep those in because I dont want to mess around with legal stuff.
Mercedes Benz C300 Muffler Delete & X-pipe, first start + take off - YouTube
EDIT: as for the back pressure, there is some but not too much. Normally only happens when I hold a gear and slow down. Sometimes I'll hear a loud pop but its random.