[Rox335i]

1. Currently have a borla atak catback on my 335i and if I put a catless dp on it, will it be to loud?

2. If I don't have a tune, will it 100% give a cel when it's installed?

3. Are there anything to change prior to the downpipe install or is a stock car fine to have a catless downpipe.

4. How strong is the smell? Driving in the car and outside standing behind the car.

5. Is it worth it? Is coldstarts, warm start, And WOT louder? What about cruising?

[thejeremyman9]

1. Too loud is subjective, but it will be significantly louder with the catless compared to OEM DP. It will increase volume and drone, and change the tone. There are several threads and video on people's experience with various exhaust+DP combos.

2. Yes, catless DP will unavoidably give you a CEL. Your catalyst emission monitor will also not be 'ready', if that matters for you.

3. A stock car can have a catless DP. You will benefit from the reduction in backpressure, but the benefits are generally increased as you demand more from the turbo with a tuned car.

4. Subjective. Read the dozens of threads and posts on this. You are going to hear both sides from people who love it and people who hate it, plus people in the middle who tolerate it. I daily drove a catless car for about 10 years before getting my 335 and went fabspeed catted specifically because i didnt want this car to smell like fumes. In the car it wont really be noticeable while driving, but at stoplights it will be. Behind the car it certainly will be. The smell is strong, especially if you are not used to it. Passengers will notice it.

5. Worth it in what context? A DP upgrade is certainly worth it, but depending the whole number of factors such as sound, smell, cost, etc, you should decide between catted and catless. This debate has already been beat to death so just read the threads if you feel like you lack the info to make an informed decision. Everything is going to be louder with a catless DP. Cold starts are going to be extremely loud with an aftermarket exhaust.

[Munchi435i]

1. Currently have a borla atak catback on my 335i and if I put a catless dp on it, will it be to loud? yes it will be louder
2. If I don't have a tune, will it 100% give a cel when it's installed?
yes it will cause a CEL
3. Are there anything to change prior to the downpipe install or is a stock car fine to have a catless downpipe.
no additional parts or procedures required
4. How strong is the smell? Driving in the car and outside standing behind the car.
smell will depend on your sensitivity
5. Is it worth it? Is coldstarts, warm start, And WOT louder? What about cruising?
IMO yes it worth it from a performance standpoint. Yes it will be louder. Yes there will be some drone and yes it will be louder

[Rox335i]

Originally Posted by thejeremyman9

1. Too loud is subjective, but it will be significantly louder with the catless compared to OEM DP. It will increase volume and drone, and change the tone. There are several threads and video on people's experience with various exhaust+DP combos.

2. Yes, catless DP will unavoidably give you a CEL. Your catalyst emission monitor will also not be 'ready', if that matters for you.

3. A stock car can have a catless DP. You will benefit from the reduction in backpressure, but the benefits are generally increased as you demand more from the turbo with a tuned car.

4. Subjective. Read the dozens of threads and posts on this. You are going to hear both sides from people who love it and people who hate it, plus people in the middle who tolerate it. I daily drove a catless car for about 10 years before getting my 335 and went fabspeed catted specifically because i didnt want this car to smell like fumes. In the car it wont really be noticeable while driving, but at stoplights it will be. Behind the car it certainly will be. The smell is strong, especially if you are not used to it. Passengers will notice it.

5. Worth it in what context? A DP upgrade is certainly worth it, but depending the whole number of factors such as sound, smell, cost, etc, you should decide between catted and catless. This debate has already been beat to death so just read the threads if you feel like you lack the info to make an informed decision. Everything is going to be louder with a catless DP. Cold starts are going to be extremely loud with an aftermarket exhaust.

So if I do get a dp and I don't plan on tuning the car and just leave the CEL there (ext warranty already expired), I won't know if the car actually have a problem right?

[thejeremyman9]

Originally Posted by Rox335i

So if I do get a dp and I don't plan on tuning the car and just leave the CEL there (ext warranty already expired), I won't know if the car actually have a problem right?

Well it's not that you wont know, it just may not be as obvious. You would likely still get a drivetrain malfunction and the car would go into limp mode or exhibit other behavior in response to any other problem that might come up, but if a problem were to come up that would trigger a CEL without any noticeable change in drivability or drivetrain malfunction, you may not notice. This is particularly true if you don't scan for codes (and shadow codes).

Consider your goals with the car and if a catless DP is really the path you want to go down, based on all the pros/cons of the DP in itself, a DP relative to other mods, whether or not you want to tune, etc.

[Silverlining_m2]

I was concerned about the smell of the catless definitely. Having done it this past weekend, I can say

1. I don't mind the smell outside the car. It smells like a race car to me.
2. I can't smell it inside the car at all with the windows up, whether stopped at a light or not. I have not been stuck in a traffic jam with it yet.
3. With a stage 2 tune the performance enhancement is pretty incredible from stock, and it even surprised me coming from stage 1. I believe the consensus is close to 400hp with catless dp/fmic/cp and a tune.
4. It is louder on cold start, with the flaps open in sport mode, and on the highway in sport it does have a small amount of drone. None in comfort.

[Rox335i]

Originally Posted by f32spaceship

I was concerned about the smell of the catless definitely. Having done it this past weekend, I can say

1. I don't mind the smell outside the car. It smells like a race car to me.
2. I can't smell it inside the car at all with the windows up, whether stopped at a light or not. I have not been stuck in a traffic jam with it yet.
3. With a stage 2 tune the performance enhancement is pretty incredible from stock, and it even surprised me coming from stage 1. I believe the consensus is close to 400hp with catless dp/fmic/cp and a tune.
4. It is louder on cold start, with the flaps open in sport mode, and on the highway in sport it does have a small amount of drone. None in comfort.

Is cruising still louder than stock dp? I heard that catless is only louder on cold starts and WOT?

[Silverlining_m2]

Originally Posted by Rox335i

Is cruising still louder than stock dp? I heard that catless is only louder on cold starts and WOT?

Bm3 keeps both exhaust flaps open in sport modes. So that's always louder. Personally I don't find comfort much louder, but it is a little. I prefer that for highway drives.

I pretty much drive 2 different ways. Dct completely off (comfort mode with no traction control) and trans in sport mode. Or sport+ with the trans in sport mode. The latter is louder, but the former is preferred for steady highway driving, to me.

[thejeremyman9]

Originally Posted by f32spaceship

Bm3 keeps both exhaust flaps open in sport modes. So that's always louder. Personally I don't find comfort much louder, but it is a little. I prefer that for highway drives.

I pretty much drive 2 different ways. Dct completely off (comfort mode with no traction control) and trans in sport mode. Or sport+ with the trans in sport mode. The latter is louder, but the former is preferred for steady highway driving, to me.

What exhaust do you have? OP has a borla atak.

Originally Posted by Rox335i

Is cruising still louder than stock dp? I heard that catless is only louder on cold starts and WOT?

Just to be clear, the sound/volume change from a DP depends heavily on what exhaust you are running. Going from OEM to catless DP with a completely stock exhaust is going to be a minor change in sound/volume as compared to going from OEM to catless DP with a borla atak. The louder your exhaust is to begin with, the more the catless DP is going to increase volume and drone. Hence, the question i asked above to f32spaceship is key.

There is absolutely no question that the catless DP is going to be significantly louder than OEM in all modes and driving conditions with your borla atak. Just want to make sure you are aware of what you might be in for. Many of these aftermarket exhaust are designed to be paired with OEM DP, which in itself tames volume and drone quite a bit.

Think about it this way - Let's say the volume after the DP is 5 with OEM DP and 10 with catless DP. Lets say OEM catback exhaust reduces volume by 60% and borla atak by 20%. Your current volume is 4. Going catless with the atak is going to bring you up to 8. If you were to go from OEM DP to catless with OEM exhaust, you would only go from 2 to 4. So the actual change from adding the DP is going to be more depending on the exhaust, not to mention louder to begin with. Numbers are for illustrative purposes only.

[Silverlining_m2]

Originally Posted by thejeremyman9

What exhaust do you have? OP has a borla atak.

Just to be clear, the sound/volume change from a DP depends heavily on what exhaust you are running. Going from OEM to catless DP with a completely stock exhaust is going to be a minor change in sound/volume as compared to going from OEM to catless DP with a borla atak. The louder your exhaust is to begin with, the more the catless DP is going to increase volume and drone. Hence, the question i asked above to f32spaceship is key.

There is absolutely no question that the catless DP is going to be significantly louder than OEM in all modes and driving conditions with your borla atak. Just want to make sure you are aware of what you might be in for. Many of these aftermarket exhaust are designed to be paired with OEM DP, which in itself tames volume and drone quite a bit.

Think about it this way - Let's say the volume after the DP is 5 with OEM DP and 10 with catless DP. Lets say OEM catback exhaust reduces volume by 60% and borla atak by 20%. Your current volume is 4. Going catless with the atak is going to bring you up to 8. If you were to go from OEM DP to catless with OEM exhaust, you would only go from 2 to 4. So the actual change from adding the DP is going to be more depending on the exhaust, not to mention louder to begin with. Numbers are for illustrative purposes only.

You're right!! I only have stock exhaust with no big exhaust plans. If he has a naturally louder exhaust, it's definitely gonna get louder. I personally am pleased with the catless dp sound in my stock dual exhaust. I would not want it louder.

[Rox335i]

Originally Posted by thejeremyman9

What exhaust do you have? OP has a borla atak.

Just to be clear, the sound/volume change from a DP depends heavily on what exhaust you are running. Going from OEM to catless DP with a completely stock exhaust is going to be a minor change in sound/volume as compared to going from OEM to catless DP with a borla atak. The louder your exhaust is to begin with, the more the catless DP is going to increase volume and drone. Hence, the question i asked above to f32spaceship is key.

There is absolutely no question that the catless DP is going to be significantly louder than OEM in all modes and driving conditions with your borla atak. Just want to make sure you are aware of what you might be in for. Many of these aftermarket exhaust are designed to be paired with OEM DP, which in itself tames volume and drone quite a bit.

Think about it this way - Let's say the volume after the DP is 5 with OEM DP and 10 with catless DP. Lets say OEM catback exhaust reduces volume by 60% and borla atak by 20%. Your current volume is 4. Going catless with the atak is going to bring you up to 8. If you were to go from OEM DP to catless with OEM exhaust, you would only go from 2 to 4. So the actual change from adding the DP is going to be more depending on the exhaust, not to mention louder to begin with. Numbers are for illustrative purposes only.

Cool thanks to know!

Would you think a straight pipe ( no resonators and muffler) would be louder than my Borla atak catback with catless dp? I was straight piped prior to my atak and would want to know which would be louder.

It's hard to judge catback exhausts with catless downpipe by watching a video. Hard to notice a difference with my ATAK with OEM DP.

[thejeremyman9]

Originally Posted by Rox335i

Cool thanks to know!

Would you think a straight pipe ( no resonators and muffler) would be louder than my Borla atak catback with catless dp? I was straight piped prior to my atak and would want to know which would be louder.

It's hard to judge catback exhausts with catless downpipe by watching a video. Hard to notice a difference with my ATAK with OEM DP.

If you are asking about OEM DP + straight pipe versus catless DP + atak... no idea. Part of me wants to say the catless DP + atak will be louder, but i am speculating.

[ozymandias435]

Originally Posted by Rox335i

1. Currently have a borla atak catback on my 335i and if I put a catless dp on it, will it be to loud?

2. If I don't have a tune, will it 100% give a cel when it's installed?

3. Are there anything to change prior to the downpipe install or is a stock car fine to have a catless downpipe.

4. How strong is the smell? Driving in the car and outside standing behind the car.

5. Is it worth it? Is coldstarts, warm start, And WOT louder? What about cruising?

I originally had Borla S type with stock downpipe and loved it. Installed Fabspeed Sport Cat dp about 7 months ago so I could go Stage 2 tune. The improved air flow made the exhaust wayyyy louder in all areas. Cold starts became menacing and there was a minor but constant drone at all times cruising. I did enjoy the sound for a bit but it became too much and now I have swapped the Borla for an MPE paired with the same Sport cat DP. I love my new setup a lot so far. Yes there are plenty of times where I miss the former exhaust but on the whole I am so much happier now with my all around user experience. Not to mention my 6am cold starts don't make me cringe anymore. Just wanted to share my journey and you can use it however you choose.

[Rox335i]

Originally Posted by ozymandias435

I originally had Borla S type with stock downpipe and loved it. Installed Fabspeed Sport Cat dp about 7 months ago so I could go Stage 2 tune. The improved air flow made the exhaust wayyyy louder in all areas. Cold starts became menacing and there was a minor but constant drone at all times cruising. I did enjoy the sound for a bit but it became too much and now I have swapped the Borla for an MPE paired with the same Sport cat DP. I love my new setup a lot so far. Yes there are plenty of times where I miss the former exhaust but on the whole I am so much happier now with my all around user experience. Not to mention my 6am cold starts don't make me cringe anymore. Just wanted to share my journey and you can use it however you choose.

So you think if I get a catless downpipe, it will be louder in all area? Not just WOT and cold starts? I don't mind cold starts being loud since I don't leave early in the morning.

[thejeremyman9]

Originally Posted by Rox335i

So you think if I get a catless downpipe, it will be louder in all area? Not just WOT and cold starts? I don't mind cold starts being loud since I don't leave early in the morning.

For the 100th time, yes, catless DP is going to make it much louder in ALL respects, especially since you already have aftermarket exhaust. I dunno if you keep asking the same question hoping to get a different answer to talk you into getting the catless DP or what lol...

[n55david]

Originally Posted by Rox335i

So you think if I get a catless downpipe, it will be louder in all area? Not just WOT and cold starts? I don't mind cold starts being loud since I don't leave early in the morning.

nope just cold starts

[n55david]

Originally Posted by thejeremyman9

For the 100th time, yes, catless DP is going to make it much louder in ALL respects, especially since you already have aftermarket exhaust. I dunno if you keep asking the same question hoping to get a different answer to talk you into getting the catless DP or what lol...

don't lie to the guy, why are you doing that?

[thejeremyman9]

Originally Posted by Phantom10R

nope just cold starts

Don't troll him he might believe you lol

[n55david]

Originally Posted by thejeremyman9

Don't troll him he might believe you lol

I do that all the time in the Facebook groups. its hilarious to me

[thejeremyman9]

Originally Posted by Phantom10R

I do that all the time in the Facebook groups. its hilarious to me

Trolling on facebook is one thing... its facebook, home of the trolls. But on the forums, especially when it may not be obvious to OP given how this thread has evolved, i am more opposed.

[BMWILUVU]

Originally Posted by Rox335i

So you think if I get a catless downpipe, it will be louder in all area? Not just WOT and cold starts? I don't mind cold starts being loud since I don't leave early in the morning.

LOL its louder in cold starts but imo its slightly louder after that. If you garage the car, when you warm up and return, you WILL stink up the garage.

[Pussiwillow]

+1
RIP garage
My wife yells at me every morning to get the car out of the garage and tells me I ruined the car lmao
Women...