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MBRP 3in cat back exhaust.
- Thread starter Turbotoaster93
- Start date
I have the MBRP, love the sound, great exhaust for the money. Only have had one issue with the section that goes over the rear axle rattling once and a while but just needs a little adjustment and I think it will be fine. Otherwise I think its one the best sounding!
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Sent from my LM-G820 using Tapatalk
I have the MBRP and overall I really enjoy it. It is loud and droney on the highway between 3000-4000 rpm. So if you do a lot of 75+ mph driving then this may be a concern for you. Around town on and off the throttle it sounds epic. Cold starts are my favorite as it fires to life it sounds like it is clearing it's raspy throat and I hear it telling me "prepare to send it my dude". I have a Dizzy tune with exhaust crackles and when I shift above 3000rpm I get those awesome Audi V8 turbo pops and bangs that have so far been my favorite part of owning this car.
The one knock I have for this exhaust (and I have seen it with other FiSTs in pics) is that the tips are crooked after being installed. the inboard driver side rear most hanger hangs to low and the exhaust exit pipes need to be twisted clockwise to hang level. I have remedied this with a shorter compact rubber hanger on that side, so if you have OCD like me you'll want to adjust that.
The one knock I have for this exhaust (and I have seen it with other FiSTs in pics) is that the tips are crooked after being installed. the inboard driver side rear most hanger hangs to low and the exhaust exit pipes need to be twisted clockwise to hang level. I have remedied this with a shorter compact rubber hanger on that side, so if you have OCD like me you'll want to adjust that.
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The drone with the MBRP is ear-piercing, and definitely falls within the range that it'll cause long-term hearing loss. It's not the primary noise, the sound you hear from the exhaust outside - it's the secondary drone that resonates inside the body of the car. I was able to resolve it but it adds a few hundred bucks to the exhaust. If you are looking to avoid the drone, just get a thermal. Anyone whom says the MBRP does not drone believes so because they've probably already lost hearing in the 107hz range. It's clearly visible upon spectrum analysis. The MBRP is also not very well engineered, as the bends where it comes from the downpipe then up over the mid-chassis brace, and the little "arms" that go into the exhaust hangers, are not consistent from one exhaust to the next. That's why some people have fitment issues and others don't. I know what I am doing with exhaust system fabrication and installation, and even I have been unable to get my MBRP to fit without touching the mid-chassis brace. It results in a banging sound over bumps and occasional buzzing, even with washers added to the brace for clearance.
Thermal is the most drone-free exhaust made for the Fiesta ST, since it incorporates a properly sized quarter wave resonator into it's muffler.
The CP-E is the second most drone-resistant exhaust made for the Fiesta ST, though it's helmholtz chamber is less effective in attenuating the 106-107hz range.
There are several others that have less drone, but unless they're actively cancelling that 106hz resonance, they're going to drone (if they're 3").
If you go MBRP, don't drive the car with kids in it, you'll be causing them permanent hearing damage while their ears are still developing.
As to why I own the MBRP - I cut my hand on my custom exhaust and needed something *now* - whoosh had them in-stock, so I ordered one figuring I would also prove it was possible to make an MBRP drone-free. If Ron had had the Thermal in stock, I would have ordered one. It is possible to kill the MBRP drone, but it's complicated to do and requires modifying a brand-new exhaust. https://www.fiestastforum.com/threads/im-at-it-again-fixing-drone-on-a-brand-new-mbrp.20873/
Thermal is the most drone-free exhaust made for the Fiesta ST, since it incorporates a properly sized quarter wave resonator into it's muffler.
The CP-E is the second most drone-resistant exhaust made for the Fiesta ST, though it's helmholtz chamber is less effective in attenuating the 106-107hz range.
There are several others that have less drone, but unless they're actively cancelling that 106hz resonance, they're going to drone (if they're 3").
If you go MBRP, don't drive the car with kids in it, you'll be causing them permanent hearing damage while their ears are still developing.
As to why I own the MBRP - I cut my hand on my custom exhaust and needed something *now* - whoosh had them in-stock, so I ordered one figuring I would also prove it was possible to make an MBRP drone-free. If Ron had had the Thermal in stock, I would have ordered one. It is possible to kill the MBRP drone, but it's complicated to do and requires modifying a brand-new exhaust. https://www.fiestastforum.com/threads/im-at-it-again-fixing-drone-on-a-brand-new-mbrp.20873/
Since you have extensive experience regarding this exhaust and drone, I have a question for you; For those that want the MBRP quieter in that drone RPM range do you think a small race bullet style muffler would help? This is a Dynomax 3" that I believe is only 9" in total length and would fit easily in front of the Y section in the rear and the last bend around the shock tower area. And they are less than $30.
I have the Cobb and its pretty plain compared to the others. Not much different than stock to be honest.
I looked into MBRP and decided against it because of the numerous accounts of drone. I've had a WRX before with a full 3" turbo back and its amazing I still have hearing, was almost 140db when tested. I did not want that again.
Thermal is daily the most recommended, and I mean daily....it is literally recommended daily when people ask.
I looked into MBRP and decided against it because of the numerous accounts of drone. I've had a WRX before with a full 3" turbo back and its amazing I still have hearing, was almost 140db when tested. I did not want that again.
Thermal is daily the most recommended, and I mean daily....it is literally recommended daily when people ask.
No - the problem is that the "Drone" is a wave roughly 10 feet long, a short-bodied bullet silencer will only filter higher frequencies (~200-240hz with those tiny ones) which will just make it deeper. You need to attenuate a really long wave, and the only ways to do that without a 10+ foot long muffler are either a helmholtz chamber (like CP-E) or a quarter wave chamber (thermal, my custom one). Unfortunately it's not a matter of just packing in more mufflers. I had read that Thermal sells standalone mufflers, but I do not know if that means they'll sell the one with the built-in quarter wave resonator.
I think there are a few muffler manufacturers out there that build quarter wave resonators into their mufflers, like Corsa and maybe Billy Boat, but I haven't been able to get email replies from either about attenuating a specific range.
As long as you can avoid ~3200rpm under load it's generally fine, there's just a ~700rpm range where it attenuates absurdly loudly. The 3" diameter and shape of the MBRP bends allows the system to get an undisturbed wave all the way down it's length - if it was 2.5" it wouldn't do it, or if the bends were sharper, but as-is it's almost like the body of a trombone 
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