[flyknit]

Originally Posted by mike@x-ph.com

We carry Wagner, VRSF, Evolution Racewerks & CG Precision. Either option will work for the stage 2 (catless or catted)

gains are the same on stock turbo

You mean regardless catted or catless the gain are same on stock turbo?

[mike@x-ph.com]

Originally Posted by flyknit

You mean regardless catted or catless the gain are same on stock turbo?

Correct

[flyknit]

I see. In this case it won’t make much diff whether catted or catless if I have no intention to change stock turbo then. Probably won’t smell as bad if go catted

[kern417]

Originally Posted by G.Newt

It's not that bad and no one has ever said anything because they can probably barely smell it. If you're standing right behind my car, it's pretty noticeable though.

I was about to say, it may not smell to you but everyone driving behind you, hates you

I have gone catless in the past and I'm contemplating doing the same. I'd never run a stage 2 flash with stock downpipe and the stage 1 flash is plenty of power, but it's just so easy to get an extra 20-30hp it's hard to pass up.

Going from catted to catless changes the tone more than the volume. It sounds more raw. The car also feels a little more peppy, but not heaps of power like going stage 1 to stage 2. The only real benefit is catless is cheaper and it's one less thing to worry about failing. But if you don't mind spending the coin, i'd go high flow cat.

[bacon_45]

On a b58 going catless changes the loudness pretty significantly. Cold starts are crazy loud even with one valve closed.

[nikman011]

Originally Posted by bacon_45

On a b58 going catless changes the loudness pretty significantly. Cold starts are crazy loud even with one valve closed.

My high flow catted DP is CRAZY loud on cold start

[Alarmin]

I've got a BM3 Stage 1 tune and am looking into getting a DP for my car so I can run stage 2. I already have a Dinan catback exhaust. I was wondering if anyone could speak to the following:

1) Could you give a ballpark percentage of how much louder a catted DP would make a catback exhaust vs stock DP while driving? Not worried about cold start volume since I can turn that off with BM3.

2) How bad is the smell for a catted dp in the cabin? Is it super noticeable? Just wondering if this can be installed without my wife giving me any grief lol.

3) Any recommendations for catted DPs?

Thanks in advance everybody.

[bmw22915]

Originally Posted by Alarmin

I've got a BM3 Stage 1 tune and am looking into getting a DP for my car so I can run stage 2. I already have a Dinan catback exhaust. I was wondering if anyone could speak to the following:

1) Could you give a ballpark percentage of how much louder a catted DP would make a catback exhaust vs stock DP while driving? Not worried about cold start volume since I can turn that off with BM3.

2) How bad is the smell for a catted dp in the cabin? Is it super noticeable? Just wondering if this can be installed without my wife giving me any grief lol.

3) Any recommendations for catted DPs?

Thanks in advance everybody.

1) about 40 percent louder. Definitely noticed.

2) no smell in the cabin from high flow cat. Maybe if you're standing behind your car when it's running, but it's faint. Never had a passenger complain or mention any smell. You can definitely smell the Catless though

3) CG Precision DS-1 catted 200 cel. I haven't had a check engine light with that downpipe. Runs for about 1k, but highly recommended and tested.

[Alarmin]

Originally Posted by bmw22915

1) about 40 percent louder. Definitely noticed.

2) no smell in the cabin from high flow cat. Maybe if you're standing behind your car when it's running, but it's faint. Never had a passenger complain or mention any smell. You can definitely smell the Catless though

3) CG Precision DS-1 catted 200 cel. I haven't had a check engine light with that downpipe. Runs for about 1k, but highly recommended and tested.

Thanks so much for the info. 40% is a hell of an increase lol - my neighbors will definitely hate me if I go that route (doesn't mean its off the table). Great to hear about the smell and Check engine light though.

[G.Newt]

Originally Posted by Alarmin

Thanks so much for the info. 40% is a hell of an increase lol - my neighbors will definitely hate me if I go that route (doesn't mean its off the table). Great to hear about the smell and Check engine light though.

Once you run a flash tune and delete the cat heating (loud cold start) it's not bad at all. I turned down my burbles and gunshots (non-existent anymore) so now it's just a loud, nice sounding straight 6 without the pops and bangs that scare people.

[bmw22915]

Originally Posted by G.Newt

Once you run a flash tune and delete the cat heating (loud cold start) it's not bad at all. I turned down my burbles and gunshots (non-existent anymore) so now it's just a loud, nice sounding straight 6 without the pops and bangs that scare people.

This is the solution ^

[heusing240i]

Originally Posted by G.Newt

It's not that bad and no one has ever said anything because they can probably barely smell it. If you're standing right behind my car, it's pretty noticeable though.

I recently installed the 4.5 VRSF catless on my m240i with stock exhaust. Finding myself in a love/hate relationship with the cold start but find the sound while driving to be very tolerable. Maybe even a little to quiet. One thing I've noticed on the JB4, with the flapper disabled, it is still closed when I turn the car on for the first 3 or so seconds.

As far as smell goes, you can smell it. I don't mind it as I am running 1/2 90 octane ethanol free and 1/2 100 octane with 10%. Not as good smelling as classic big blocks but still burns well.

[TBONE1969]

I just installed a CG DS-1 this last Sunday. Measured a 79dB cold start with my phone 12" from the right rear exhaust before the install and 89dB after the install. I haven't noticed much smell so far. Sound is really nice imho. Not a very noticeable power change, but that will change when I get a stage 2 tune.

[mike@x-ph.com]

Originally Posted by TBONE1969

I just installed a CG DS-1 this last Sunday. Measured a 79dB cold start with my phone 12" from the right rear exhaust before the install and 89dB after the install. I haven't noticed much smell so far. Sound is really nice imho. Not a very noticeable power change, but that will change when I get a stage 2 tune.

Congrats!

Please post a sound clip

[flyknit]

Does the dp size varies between region/location? Friend recently bought ER catted (label says for b58) for his 340 but end up can’t fit.

[G.Newt]

Originally Posted by flyknit

Does the dp size varies between region/location? Friend recently bought ER catted (label says for b58) for his 340 but end up can’t fit.

Nah. Seriously doubt BMW has entire different production lines just because of exhaust. That sounds like a product defect. I'd reach out to ER with picture of the misalignment.

[Pszyk m40i]

Just installed active autowerke downpipe, mst intake and mhd stage 2 from extreme Power House and could not be more happy sounds and performance is awesome