[SomethingBlue]

I've been kicking around the idea of switching to a catless DP on my F32, but I'm not at all interested in any of the noisy pops and noise that I've heard in pretty much every single YouTube video that demonstrates catless DP's. Some folks have said that BootMod3 can tune out the loud bangs and gunshot noises, but I'd really like to see some videos if anyone knows of any.

I'm all for the performance gain, but I don't want my car to be any more of a cop magnet than it might already be (dark tint all around plus no front plate).

Has anyone here gone catless but managed to keep the noise to a minimum? I have MPPK and M Performance Exhaust now, the butterfly valves are disconnected because that's the way it was when I bought it. I might reconnect them, but I really have no interest in the loud crackling once you let off the gas pedal.

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[SomethingBlue]

Originally Posted by LobB

Won't that fail emission testing?

Yep. I just had the car smogged, so I can swap it out when it comes due next. 4 years?

[kern417]

From what i've seen the MPPSK is what adds lot of pops and bangs itself. The catless downpipe will make it louder unless you replace your exhaust with a quieter muffler.

[XxThe_RemedyXx]

Originally Posted by kern417

From what i've seen the MPPSK is what adds lot of pops and bangs itself. The catless downpipe will make it louder unless you replace your exhaust with a quieter muffler.

Before I flashed BM3, I had MPPK and MPE with catless VRSF DP installed. Lots of growl and burbling but NO gunshots at all. After flashing BM3 to Stage 2 AGG 93 and setting burble to either OEM or OTS, that's when gunshots started occurring. It was a bit much for my taste so I flashed back to Stage 2 NON AGG and set burbles to OTS. Nice balance of burble and growl with NO gunshots, just what I was looking for.

MPPSK with catless DP won't give you gunshots alone if that's what you're after. Only a flash tune will give you that.

[kern417]

Yeah I wasn't differentiating between gunshots and burbles. I see what you mean now. I like the burbles on overrun but not really interested in the "gunshots" either.

[XxThe_RemedyXx]

Originally Posted by kern417

Yeah I wasn't differentiating between gunshots and burbles. I see what you mean now. I like the burbles on overrun but not really interested in the "gunshots" either.

[Mike.]

Im catless with the stock exhaust. Its pretty tame..just some overrun

[BEAR-AvHistory]

Originally Posted by SomethingBlue

Yep. I just had the car smogged, so I can swap it out when it comes due next. 4 years?

Sounds like a plan if you don't have to smog test every year. Never went cat-less due to annual inspections in NC & cat swapping is a bi**h. With cats in-place was still able to get over 400WHP out of the 335is on 100 octane.

Thing about Carolina is they are so concerned about the environment cars like my COBRA are exempt from the regulations & annual testing. Lots of specialty cars running around here without EGR & Cats.

I just feel so guilty when I drive it.

[Niart906]

There are high flow catted downpipes available for these cars. Might be worth looking into, the cats help to reduce the pops in my experience.

[SomethingBlue]

Originally Posted by Niart906

There are high flow catted downpipes available for these cars. Might be worth looking into, the cats help to reduce the pops in my experience.

Right, and that was my original plan, suck it up and just pay more for a Fabspeed since I didn't want to bother with the CEL's and figured it would still pass emissions. But the argument keeps getting presented to me that the most bang for the buck for this engine is a tune and a catless DP and going with a high flow cat is a good way to spend a lot of money and not really see much difference.

The complete lack of hard crackles and pops is more important to me however, than another 40-50 or whatever horsepower that I probably wouldn't get to use anyway, except on very rare occasions.

I just wouldn't entertain the concept of going catless unless I knew for sure it wouldn't sound like every other catless BWM I've ever heard does.

[Insane435]

To answer the original question, get bootmod3, and modify the OTS map of your choice. You can turn the burble duration and intensity to "zero". Modifying the map is very easy and takes just seconds. These cars have burbles from factory, just fyi.