Real Talk: Catless downpipe (my experience)

[EuroCarFan]

Great thread.

I've been so tempted to get catless DPs but have held off due to the smell and noise. My E60 M5 is catless and the fumes are insane. My kids hate it. And of course, the V10 is LOUD! It sounds awesome but with the low torque on that motor, you kinda have to get on it even in "normal" driving and I always wonder if people think I'm speeding or trying to show off. LOL

Seems like there are good solutions offered on this thread to tame the noise but still worried about the smell.

Then there's smog.... :/

[KLR X5M]

Originally Posted by EuroCarFan

Great thread.

I've been so tempted to get catless DPs but have held off due to the smell and noise. My E60 M5 is catless and the fumes are insane. My kids hate it. And of course, the V10 is LOUD! It sounds awesome but with the low torque on that motor, you kinda have to get on it even in "normal" driving and I always wonder if people think I'm speeding or trying to show off. LOL

Seems like there are good solutions offered on this thread to tame the noise but still worried about the smell.

Then there's smog.... :/

Turbo cars do not smell nearly as bad as na or supercharged catless motors. Unless you are in low speed traffic with windows down, you won't really smell it.

[JRock80]

Originally Posted by forum_ghost

Just wanted to briefly share my experience an opinion for anyone wanting to get a catless DP. Another member said something and it made me realize that i feel the same and just wanted to say something.

A lot of times, people do certain mods and won't own up if it was a bad decision. I see a lot of people talking about their experience with DPs and I'm beginning to think that some are not honest about it.

I have a F85 X5M, AFE intake, a few cosmetic mods and running BM3 tune. yesterday I installed a set of VSRF ceramic coated intakes after listing to any clips i could find online. Installation went great and before even driving it aggressively (shop is down the street and was stuck in traffic), I went home and immediately flashed to the BM3 stage 2, 93 octane tune. I took the car for a test drive right after.

My findings?

The Good -the car was definitely more powerful, the acceleration felt almost uncontrollable as the nose of the vehicle lifted up when I did a launch from a dig....butt dyno says significant power (mostly due to the tune, DP, intake combination.....Great

The Bad - THE CAR IS WAAAAYYY TOO LOUD! I didn't buy an X5M for it to sound like a freaking 90s civic with a fart can on steroids!...granted my exhaust is stock but for some reason, my car is louder than any clip i've heard....it's so loud that i find myself driving in efficiency mode very conservatively. because as soon as i open it up, every person on the street will get whiplash and the dead will rise.....I can't do it.

Long story short, I'm removing them next week and will either go catted or back to stock. Hope this helps anyone thinking about buying.

Oh. lastly there is definitely a smell, but i think i can live with it if it wasn't so loud....just thought i would share my negative experience.

In terms of my experience, The car is noticeably louder than stock but not overbearing, in my opinion. My setups - BM3 Stage 2 AGG, VSRF downpipes and Dinan Exhaust. I am always in Sports plus mode!!!

Regarding the smell it can be a little bit daunting after running the car for a while - other than that it's barely noticeable.

If I had a complaint it would be on down shifts, high RPM and sports plus mode. Car spits 🔥- so yes that part is extremely loud.

@instagram
https://www.instagram.com/x5m_f85_jrock/

[StatenEye]

Originally Posted by KLR X5M

Turbo cars do not smell nearly as bad as na or supercharged catless motors. Unless you are in low speed traffic with windows down, you won't really smell it.

Yes, this is true.

[EuroCarFan]

Originally Posted by KLR X5M

Turbo cars do not smell nearly as bad as na or supercharged catless motors. Unless you are in low speed traffic with windows down, you won't really smell it.

Good to know. Need to find someone with a catless setup to check it out in person.

[KLR X5M]

Originally Posted by JRock80

In terms of my experience, The car is noticeably louder than stock but not overbearing, in my opinion. My setups - BM3 Stage 2 AGG, VSRF downpipes and Dinan Exhaust. I am always in Sports plus mode!!!

Regarding the smell it can be a little bit daunting after running the car for a while - other than that it's barely noticeable.

If I had a complaint it would be on down shifts, high RPM and sports plus mode. Car spits 🔥- so yes that part is extremely loud.

@instagram
https://www.instagram.com/x5m_f85_jrock/

This proves my point about perception. I found with agg burbles is loud and annoying as fuck. I drove it like that for 10 mins and immediately went and flash it back to regular stage 2. Its funny for a bit, but becomes annoying really fast. Did you do dinan before or after dps?

Edit... checked out your IG. Your setup is insanely loud. Not really for most peoples tastes i would guess. But sounds awesome......for a bit

[JRock80]

Originally Posted by KLR X5M

This proves my point about perception. I found with agg burbles is loud and annoying as fuck. I drove it like that for 10 mins and immediately went and flash it back to regular stage 2. Its funny for a bit, but becomes annoying really fast. Did you do dinan before or after dps?

Edit... checked out your IG. Your setup is insanely loud. Not really for most peoples tastes i would guess. But sounds awesome......for a bit

I was initially running Dinantronics without dps - just the cold air intakes. When I decided to go with BM3 I had the dps and exhaust installed at the same time.

[forum_ghost]

Originally Posted by StatenEye

Now this is a productive thread. Can we change the title to garner more interest / input?

How do i change the title?

[Klienfeld303]

Originally Posted by StatenEye

Furthermore, I would inspect the installation when they put the car up. Sounds like they didn't put the vband clamps back on or the pipes have terrible fitment if its that loud. Even if you leave off the gaskets it shouldn't be that loud. Mine sounds stock unless I get on it, especially with the valves closed. If I drive in normal mode, what ever the car's default is, it sounds very pedestrian. I have 2 cars with this engine with no cats and my brother has an F10 M5 and all 3 sound slightly louder than stock under normal driving conditions. I did the install for all 3 so i know everything was done correctly. 2 have nice AR pipes and my brothers we hollowed out stocks.

Should sound something like this. https://streamable.com/2utnlv

Staten - how are you sir? Curious - did you need to do any cpu mods if you gut the stock down pipes?

[forum_ghost]

So what does everyone think. Is it better to keep the catless downpipes and add ultra quiet resonators and maybe an X pipe? or should i opt for catted downpipes?

[StatenEye]

Originally Posted by Klienfeld303

Staten - how are you sir? Curious - did you need to do any cpu mods if you gut the stock down pipes?

Hey, I'm well. Yes you will. I went with Velos in the past and now have BM3. I passed inspections in NY with both tunes. BM3 I was able to delete the cold start, not needs with cats deleted.

[Klienfeld303]

Originally Posted by StatenEye

Hey, I'm well. Yes you will. I went with Velos in the past and now have BM3. I passed inspections in NY with both tunes. BM3 I was able to delete the cold start, not needs with cats deleted.

Thanks for the info man! Appreciate it.

[pennsiveguy]

Originally Posted by KLR X5M

This proves my point about perception. I found with agg burbles is loud and annoying as fuck. I drove it like that for 10 mins and immediately went and flash it back to regular stage 2. Its funny for a bit, but becomes annoying really fast. Did you do dinan before or after dps?

Edit... checked out your IG. Your setup is insanely loud. Not really for most peoples tastes i would guess. But sounds awesome......for a bit

I love the sound of a loud, crackly exhaust on a sports car. My GT40 is hellaciously loud. But on a daily driver luxury SUV? Not to my tastes. It's out of character for the vehicle, IMO. Plus, it partially ruins the "sleeper effect." I love being able to roll up on a Mustang GT or a C5 and smoke them...or at least know I could...without them ever suspecting anything. You can't do that if they can hear you a half-mile away.

[Cbozz]

Originally Posted by KLR X5M

I used 3" Magnaflow x pipe, and vibrant 1142 3" ultra quiet resonators. I also coded the valves to be permanently open in sport modes for more growl. You'll still get nice down shift pops, but no longer obnoxious like with just downpipes.

How did you code the valves to be open in sport?
Doesn't default coding only open them in Sport Plus?

I have them unplugged but definitely would like to get that coded. thanks

[KLR X5M]

Originally Posted by Cbozz

How did you code the valves to be open in sport?
Doesn't default coding only open them in Sport Plus?

I have them unplugged but definitely would like to get that coded. thanks

Done with bm3 tune options. Sets it to fully open in sport and sport plus

[cr8tive]

finally pulled the trigger. i replaced the resignators and put in an x pipe. what a night and day difference. im no longer embarrassed to rev my engine lol. it no longer sounds like fart in a tin can lmao and since i have the dinan air filter, wow... that sound from the engine when you floor it

[KLR X5M]

You're welcome!

[VETTEPRO]

I read about guys that say their cars are ridiculously loud with downpipes. I really don't see how that can be. The turbos act like mufflers before the exhaust even gets to the pipes.
I ran Racing Dynamics downpipes with an X pipe and modified stock mufflers.
I didn't think it was too loud at all. With the windows up, it was nice driving. There was no noticeable drone and I had no trouble listing to music or audiobooks. My wife never commented on the exhaust being too loud.
The smell did bother me so I added a set of 3" Bassani cats. The smell is better but now I wish it was a little louder.
I have most of the holes welded up inside the main muffler body.
Now I'm going to go into the fat part that sticks out of the side of the muffler and do the same with it.
I have a couple of mufflers to play with.
I am not a crazy kid who wants their car to scare people as they go by. It drives me nuts when kids bring their Vettes to my shop and you can't hear yourself think. I just hate driving them while I'm tuning them.
I'm in my 60s and build some extremely fast cars for a living. I appreciate a really good sounding vehicle. That's why I probably have over 50 hours of labor into experimenting with different modifications to my exhaust system. It's been off and cut apart more times than I can remember.
I had a modified F10 M5 and I actually cut a set of mufflers from my 2016 Z06 in half and got them to fit. It sounded awesome when I was done.

[BigHunk]

Originally Posted by forum_ghost

So what does everyone think. Is it better to keep the catless downpipes and add ultra quiet resonators and maybe an X pipe? or should i opt for catted downpipes?

Just go catted, you can add x pipe later.
But that's weird, downpipes add little more to sound, but not so much if exhaust is stock.