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Discussion Starter · #1 · (Edited)
Just added Cobb stage 1, now looking to get additional bolt-on performance and I keep seeing the discussion with down pipes. I'm also look for cat or axle-back exhaust, but now wanting anything obnoxious if reference to sound and drone. Yes I'm beating a dead horse, but cant seem to get an opinion from a reliable source thats of age.

Also, maybe to improve the exhaust note. Will the down-pipe assist with that, and also allowing for any performance gains while keeping the OEM exhaust?
 

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I think most on here will say you can do the DP and keep the stock exhaust... the DP is needed along with a FMIC upgrade to get to a stage 3 tune. Warranty will go bye bye unless you swap it out when you go for warranty work
 

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Cat back exhaust won't aid you in horsepower until you go big turbo.
At that point your exhaust will be too restrictive.

A 3" catless downpipe is the way to go if you can get away with it in your area, if not a high flow cat will do you well.

As for noise and drone, you'll have that, it's a 4 banger with a turbo. if you don't want a whole lot of drone go with a catted downpipe and a 2.5" exhaust.

Warranty info, this is such an annoying question to answer all the time. Everything and anything can get you a denied warranty claim.
Depends on the dealer you're dealing with and how they treat their customers. Talk with your local car guys and find out who they deal with and go from there.

Exhaust shouldn't deny you anything warranty wise as it's pretty much impossible for it to break anything that's covered under warranty.

Bolt on performance is only going to do something for you if you tune it. Get an accessport and a protuner and do data logs. Otherwise, your ECU is compensating for what you did and targeting for original numbers.
Of course with a tune leads to a bigger possibility for warranty claims being denied.
 

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Discussion Starter · #4 ·
Okay, I think I'll leave the OEM downpipe for now. I would like to to get either a axle-back or catback, it seems theres only 1 option on axle back. I'm not a kid, so exhaust tone is everything. I cant the deepest sound possible, I cant deal with that coffee can crap, I want deep and no drone.
 

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If you're looking for no drone, although this experience comes from another car, borla is the way to go. I had a 1.4t car with a catless DP to a high flow second cat and borla cat back. I swear I could not hear my exhaust at all inside the car but my buddy could hear me coming from a block away. Over other platforms, borla is good with engineering cat backs with no to minimal drone.

Sent from my SM-G955U1 using Tapatalk
 

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I have the MRT. Deeper purr, no drone. On my first ST i deleted the muffler in back and replaced the resonator with a magnaflow muffler. Deeper
still, somewhat louder, minimal, if any, drone.
 

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Okay, I think I'll leave the OEM downpipe for now. I would like to to get either a axle-back or catback, it seems theres only 1 option on axle back. I'm not a kid, so exhaust tone is everything. I cant the deepest sound possible, I cant deal with that coffee can crap, I want deep and no drone.
The magnaflow DP is always a option. It doesn't have the nasty kink the oem one has, same size as oem on the exhaust flange and has a higher flow cat. It has been long forgotten in the Focus world

https://www.magnaflow.com/products?partNumber=51633
 

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Factory DP is hilarioulsy restrictive. it's also really flexible which will probably make you laugh when you take it off the car.
For sure be looking into a more solid option. You'll also want to upgrade the exhaust hangers (the rubber ones) they let the heavier exhausts swing and bang into the sides too much.

Good luck man.
 

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Ford_focus_ST_250_mk3_Downpipe_and OE_Catalyst_flow_restriction0.jpg
Well, does this answer what I mean by "Hilariously restrictive"?
 

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I am sure you can get more than 6HP.... the down pipe on turbo cars can be one of the most restrictive components. Look at the pic of the stock one. Also since it is required for a stage 3 shows its performance needs.
 

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No, no, no! That’s not restrictive. That’s actually a design feature that’s there to make sure you don’t let all the exhaust out at once. It’s conserving exhaust gasses! :crazy:
Damn... I'm dumb hahahaha.
From an engineering standpoint it appears to create a venturi effect where it will actually suck the gases out of the turbo at a high rate of speed actually increasing exhaust flow.
 

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If you are looking for more sound, with no drone, I suggest you check out Thermal R&D. There are almost too many different cat back systems for our cars to choose from, but I'm leaning toward Thermal R&D because it seems to have a more mature sound and seems to be well made. There are plenty of others that fit the bill as well.
The cars at Octane Academy use the Ford Racing Performance Parts catbacks, which I am told are made by Borla. I have no idea what downpipe they use, but I suspect they are straight through with no catalytic converter. The cars are LOUD, which is great when you are driving them on the track, but I certainly would not want my car to be this loud.
 

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If you are looking for more sound, with no drone, I suggest you check out Thermal R&D. There are almost too many different cat back systems for our cars to choose from, but I'm leaning toward Thermal R&D because it seems to have a more mature sound and seems to be well made. There are plenty of others that fit the bill as well.
The cars at Octane Academy use the Ford Racing Performance Parts catbacks, which I am told are made by Borla. I have no idea what downpipe they use, but I suspect they are straight through with no catalytic converter. The cars are LOUD, which is great when you are driving them on the track, but I certainly would not want my car to be this loud.
I can second the Thermal R&D catback. I actually own it and has been on my car for 4 months and owned the car for 7 now. There is zero to very little drone on the interior even under WOT.
noise wise under 15-25% throttle its a fairly quite aggressive sound, after the 15-25% is when the it starts picking up a louder more aggressive tone. the Cobb is rated at around 96-98DB and Thermal is at 92-94DB under WOT.

 

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Okay, I think I'll leave the OEM downpipe for now. I would like to to get either a axle-back or catback, it seems theres only 1 option on axle back. I'm not a kid, so exhaust tone is everything. I cant the deepest sound possible, I cant deal with that coffee can crap, I want deep and no drone.
Go with this Magnaflow Muffler, take it to a muffler shop, have them weld it in place of your factory resonator and have them cut out your current muffler. You can either leave the stock tips or buy new ones, personal preference on the look. I love the sound of mine, it did get a little louder once i installed the COBB DP. It quiet when youre cruising and on start up, if you get on the gas, the exhaust note really sounds great, total cost, about 200 including parts and labor
 

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Anything you do, Ford will try their best to void your warranty. Even with just the AP, don?t listen to people who say you can just flash back to stock ECU settings and ford won?t know. They will. All they gotta do is read the computer and it will tell them EVERYTHING that has gone on. If you wanna keep your warranty. Leave it stock. You could probably get away with the exhaust like mentioned above though.
 
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