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Discussion Starter · #1 · (Edited)
Not sure how true this is, but from what I've heard, turbo's need a lot of air flow. From what this guy says, the resonator and mufflers restrict a lot of air flow and taking them out will help the engine.

Can anyone vouch on this? Will replacing my resonator with a y-pipe and a higher flow muffler improve the performance of the engine?

I've seen a lot of stuff about backpressure and other random **** and idk how much of that is true.

 

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Let me tell you my experience.

On my 15 Ecoboost I was looking for a little more sound. I replaced the stock mufflers with straight through Magnaflows. With the stock resonator still in place it was still too quiet. Also, there was no noticeable increase in power. I then built a y pipe like the video and replaced the stock resonator. This got me the sound I was looking for but still no noticeable increase in power.

Fast forward 2.5 years and I now have a 17 Ecoboost Mustang and was looking to improve the sound again. This time I had already installed the FP tune, CAI and a bigger intercooler. These changes made a very dramatic improvement in power with the stock exhaust. I did the y pipe first this time to see what it sounded like with stock mufflers. Just like before still too quiet and no noticable power increase. I was just about ready to order some Magnaflows again when I saw a thread on 6G talking about the CJPP house brand axle back exhaust. The reviews were very good and they were on sale at a price that was less than $100 more than buying mufflers and tips so I got them. The mufflers are quite a bit smaller than the Magnaflows but gave a great sound but still no noticeable increase in power. After a couple of weeks of daily driving this setup it would get loud with very slight changes in throttle, enough so that I didn't want to deal with it so I put the factory resonator back in. I now have the perfect sound, better than the 15 with Magnaflows.

Through all this I never noticed any increase or decrease in power. What this tells me is the stock exhaust system at stock or near stock power levels is not presenting a restriction that effects power enough to notice.

FWIW, I now have two Ecoboost resonators, neither of them have shown signs of the discoloration in the video. It is certainly heavy but when you can look in the inlet and see out the other side I wouldn't call it restrictive, more than a straight pipe but not bad.



Dave
 

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You want a real increase in power and sound in your exhaust? Change your down pipe !
Does a down pipe with cat still help or does it have to be without cat?
 

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Here is the stock downpipe with MBRP XP series Street I literally just installed exhaust
 

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I disagree with some of the comments above....while the downpipe is the most restrictive piece because it is closest to the turbo, it is not the only restriction. The stock resonator and exhaust are extremely restrictive and create tons of backpressure that negatively affect turbo performance, have you seen actual pictures of the insides of them?

While every car is different, generally speaking you want the least restrictive backpressure from your exhaust system as possible on turbocharged vehicles. That being said, it can be counterproductive to go too big in exhaust piping diameter. For our cars, assuming you're pushing less than 400-500 horsepower, a smooth 3" turbo-back exhaust is the most optimal for power. I'm a power guy so I'm not concerned with how loud the exhaust is, only performance. ( I had my wastegates dumping to atmosphere in my eclipse engines which was scary loud, youtube search "dsm o2 dump")

Before I got into my Ecoboost, I owned several turbo Eclipses and Talons and I can tell you that replacing the stock exhaust on all of them (including the mustang) definitely added horsepower. Being able to judge how much horsepower is added on the Ecoboost is more difficult as the airflow monitoring and ECU is much more advanced on the EB, so you don't get the full performance affects of a larger exhaust without a proper tune. Also having a larger and free flowing exhaust maximizes any other upgrades or tunes you may do in the future.

I don't claim to be an Ecoboost expert, as I just got into these cars a few months ago. I realize EB's are unique with regards to modifications, and the stock exhaust is not the most restrictive piece ever made, but everything I've ever read and experienced says that a larger, freer flowing, less restrictive exhaust (compared to factory) on a turbocharged car increases performance. If I can only gain 5-10hp out of it from going big....I will


Turbo Exhaust Theory
Exhaust Systems for Supercharged and Turbocharged Applications
Exhaust Design
 
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While I don't disagree with you in theory in practice the stock exhaust does not present enough of a restriction to make a noticeable difference in power on an engine at or near stock power levels. As you can read in my post above I have had all combinations on my Ecoboosts and never felt any increase or decrease in power. Not to say there is not a couple of horse power there but if you can't detect it with the butt dyno it's really not worth worrying about.

I have been modding turbo 4 cars for over 30 years and most of these cars realized a very noticeable increase in power by putting on a less restrictive exhaust, that is not the case with the Ecoboost Mustang.

The video you posted confirmed my suspicion that the resonator is basdically a straight through device and is not "extremely restrictive" like I hear reported.

I don't know at what point as you had HP the exhaust becomes restrictive but it's not at my power level which is a FP tune/CAI and bigger intercooler.

Dave
 

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Let me tell you my experience.

On my 15 Ecoboost I was looking for a little more sound. I replaced the stock mufflers with straight through Magnaflows. With the stock resonator still in place it was still too quiet. Also, there was no noticeable increase in power. I then built a y pipe like the video and replaced the stock resonator. This got me the sound I was looking for but still no noticeable increase in power.

Fast forward 2.5 years and I now have a 17 Ecoboost Mustang and was looking to improve the sound again. This time I had already installed the FP tune, CAI and a bigger intercooler. These changes made a very dramatic improvement in power with the stock exhaust. I did the y pipe first this time to see what it sounded like with stock mufflers. Just like before still too quiet and no noticable power increase. I was just about ready to order some Magnaflows again when I saw a thread on 6G talking about the CJPP house brand axle back exhaust. The reviews were very good and they were on sale at a price that was less than $100 more than buying mufflers and tips so I got them. The mufflers are quite a bit smaller than the Magnaflows but gave a great sound but still no noticeable increase in power. After a couple of weeks of daily driving this setup it would get loud with very slight changes in throttle, enough so that I didn't want to deal with it so I put the factory resonator back in. I now have the perfect sound, better than the 15 with Magnaflows.

Through all this I never noticed any increase or decrease in power. What this tells me is the stock exhaust system at stock or near stock power levels is not presenting a restriction that effects power enough to notice.

FWIW, I now have two Ecoboost resonators, neither of them have shown signs of the discoloration in the video. It is certainly heavy but when you can look in the inlet and see out the other side I wouldn't call it restrictive, more than a straight pipe but not bad.



Dave

I would VERY curious to know what the performance difference is in terms of HP from just the resonator delete and y-pipe install. I just did this to mine this morning, and while it seems to have more power, I have no idea how much more.
 

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Well as I said in my post you quoted I saw/felt no change in power. There may be some but my butt dyno is not sensitive enough to feel it.

Dave
Understood. And while I can't be 100% certain, if I were to guess, I'd say it's in the 5-8 HP range.
 

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Well as I said in my post you quoted I saw/felt no change in power. There may be some but my butt dyno is not sensitive enough to feel it.

Dave
FYI... prior to today the best 0-60 I could accomplish was 6.4 secs. Today, even though the temperature outside is in the 90's, I was able to get down to 6.2 secs. That can't be a coincidence. Again I have no real proof that there is in fact a performance gain, but it seems plausible based on my experience thus far.
 

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With a 5 to 10 hp difference from exhaust upgrade you will not feel any difference just driving around because the extra power will be at the very top of the rpm range where the engine is trying to push the most exhaust out, this will show up in performance data as you have experienced but will not really be noticeable in daily driving.
Be cautious in considering a downpipe replacement as dealers and ford tech's see them as harmful to the stock turbo and many people have reported issues after changing to an aftermarket downpipe like fuel smell, smoky exhaust, leaking turbo bearing seals and check engine lights. The factory downpipe isn't that bad to be honest and was designed in conjunction with the turbo.
Everything after the downpipe is fair game though, those mufflers are junk and that resonator is just a dead weight furnace trying to cook your butt.

That 6.2 0-60 is painful to hear, with the ford racing tune that time will drop to 5.7 to 6.0 (I have managed 5.08 on a cold night with a one in a million launch, 5.3 with a good launch but 5.7 is the typical and 6.0+ is when it is hot and the factory intercooler is being useless which is common ).
Add an intercooler with the tune and that number drops to 4.8 to 5.1, better tires and perfect launches will drop those numbers even more.
 

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With a 5 to 10 hp difference from exhaust upgrade you will not feel any difference just driving around because the extra power will be at the very top of the rpm range where the engine is trying to push the most exhaust out, this will show up in performance data as you have experienced but will not really be noticeable in daily driving.
Be cautious in considering a downpipe replacement as dealers and ford tech's see them as harmful to the stock turbo and many people have reported issues after changing to an aftermarket downpipe like fuel smell, smoky exhaust, leaking turbo bearing seals and check engine lights. The factory downpipe isn't that bad to be honest and was designed in conjunction with the turbo.
Everything after the downpipe is fair game though, those mufflers are junk and that resonator is just a dead weight furnace trying to cook your butt.

That 6.2 0-60 is painful to hear, with the ford racing tune that time will drop to 5.7 to 6.0 (I have managed 5.08 on a cold night with a one in a million launch, 5.3 with a good launch but 5.7 is the typical and 6.0+ is when it is hot and the factory intercooler is being useless which is common ).
Add an intercooler with the tune and that number drops to 4.8 to 5.1, better tires and perfect launches will drop those numbers even more.
As you mentioned, I may not be able to "feel" any extra HP I might have gained, but I do "hear" a difference, specifically at around 2100 RPM's and again at 4000 RPM's, with the turbo being much more noticeable plus an overall increased low-end growl. I'll have to wait a few more days to see, but right now I'm happy with what I have and do not have plans on doing a muffler delete, though that being said I may replace the stock mufflers with something else. After that decision is made, my next plan is to replace the intercooler, as you also suggested.
 

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As you mentioned, I may not be able to "feel" any extra HP I might have gained, but I do "hear" a difference, specifically at around 2100 RPM's and again at 4000 RPM's, with the turbo being much more noticeable plus an overall increased low-end growl. I'll have to wait a few more days to see, but right now I'm happy with what I have and do not have plans on doing a muffler delete, though that being said I may replace the stock mufflers with something else. After that decision is made, my next plan is to replace the intercooler, as you also suggested.
I also started with a resonator delete and later replaced the factory factory mufflers.
The old factory recall for the resonator melting fuel lines had me convinced that it was just a poorly engineered piece that the car would be better off without, I replaced the mufflers because I felt the factory mufflers didn't properly represent the sound the car should make, and their design struck me as terribly engineered as well.
I got the ford racing tune from the dealership when I bought the car last year, I did not get to install it for a while though because the original motor had a serious tapping issue within the first month, the cylinder bore on #3 was out of specification according to the tech and was causing piston slap, Ford replaced the shortblock and I have been trouble free ever since.
Currently waiting on my Mishimoto clone intercooler sitting in customs right now.

Sent from my SM-G960W using Tapatalk
 

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The factory mufflers or the exhaust were not designed for turbo applications, they were parts left over from other production vehicles.
And the factory exhaust makes the car sound like a Camry. Lol
 

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Not sure how true this is, but from what I've heard, turbo's need a lot of air flow. From what this guy says, the resonator and mufflers restrict a lot of air flow and taking them out will help the engine.

Can anyone vouch on this? Will replacing my resonator with a y-pipe and a higher flow muffler improve the performance of the engine?

I've seen a lot of stuff about backpressure and other random **** and idk how much of that is true.

*****Does removing the resonator for a y-pipe on my 18 ecoboost mustang possible damage or mess anything up or a warranty on my car by removing the resonator, and is it okay to do and car still get passed by inspection. My lovely grandma thinks it could damage the car, and may not increase performance but do worse then any good. I already have the flowmaster outlow axle back on and plan on adding downpipe later, when i have what i want done and can afford a tune to remove check engine light.
 

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*****Does removing the resonator for a y-pipe on my 18 ecoboost mustang possible damage or mess anything up or a warranty on my car by removing the resonator, and is it okay to do and car still get passed by inspection. My lovely grandma thinks it could damage the car, and may not increase performance but do worse then any good. I already have the flowmaster outlow axle back on and plan on adding downpipe later, when i have what i want done and can afford a tune to remove check engine light.
The Dealership would have to prove your resonator delete is what did the damage in order to not do warranty work for free and there is nothing the resonator does except keep the drone down so it can't break anything not having it. As for inspection you should be fine just check with a local shop and I don't know if you have emissions or not. Also you can get a O2 spacer so the check engine light won't come on with your downpipe. The tuners won't block the check engine light anymore because of FDA laws. I have a Catless downpipe resonator delete and Flowmaster Outlaw series axle back and I don't have a problem passing inspection because I know someone who will pass my car without a Cat and I don't have emissions in my County.
 
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