[brad65ford]

Hey guys, I need some help and advice on what to purchase. Believe I've looked at just about every catless, catted and even resonated DP's for the M3/m4 which are the same as our M2 Comp. Currently she's on stage 2 BM3 93 map only mod's are removed carbon filters and AA mid-pipe. One the reason I went with the AA mid-pipe was to increase some lower sound as well as remove some rasp which it did and I like it a lot. really don't want to put the stock mid-pipe back on just to run catless dp's which would defeat the purpose of the AA mid-pipe. But its time I do DP's since I'm choking the stage 2 tune, it seems if I run catless its going to be to raspy for my liking, plus added smell which I don't want if possible. I'd like to get a catted but I'm concerned of of the once I've seen (ER / AR) cat's may not hold up well, I was told the ESS catted pipes are like 4-6 week lead time which is crazy :-( Thought about running resonated but not sure how much it will help remove the rasp with the AA mipes and if its worth the added cost or just go Catted at that point. Any advice is welcome.

[Project_F87]

https://f87.bimmerpost.com/forums/sh....php?t=1631956

[brad65ford]

Thank you for that post. Pulled the trigger today on a resonated DP. Fingers cross, will post results.

[mike@x-ph.com]

Originally Posted by brad65ford

Thank you for that post. Pulled the trigger today on a resonated DP. Fingers cross, will post results.

Congrats

[m20e3087]

Originally Posted by mike@x-ph.com

Congrats

Mike any updates on VRSF single mid for M2C? It's hard the get in touch with the VRSF ppl on the forum or insta. I was going to pull to trigger on AA but saw that VRSF started making one for S55 M3/M4, so decided to wait.

[m20e3087]

Originally Posted by brad65ford

Thank you for that post. Pulled the trigger today on a resonated DP. Fingers cross, will post results.

You will love the DP with stage 2. I was ran stage one for about 5K miles, and recently switched to stage 2, its crazy fun. I was waiting for it to pass at least 12K miles before going stage 2. So added cat-less DP, BMC air filter, upgraded the charge pipes, and NKG plug at .020. Planing on doing the mid in the future.

[brad65ford]

Originally Posted by m20e3087

You will love the DP with stage 2. I was ran stage one for about 5K miles, and recently switched to stage 2, its crazy fun. I was waiting for it to pass at least 12K miles before going stage 2. So added cat-less DP, BMC air filter, upgraded the charge pipes, and NKG plug at .020. Planing on doing the mid in the future.

I haven't done the charge pipes nor got new plugs, but want to. Do you see both helping performance much at all?

[m20e3087]

Originally Posted by brad65ford

I haven't done the charge pipes nor got new plugs, but want to. Do you see both helping performance much at all?

With charge pipe you won't feel any difference, with spark plugs she runs bit smoother. They are both preventative maintenance. If your car is new or less than 10K I wouldn't worry about rushing out changing the plugs. I know guys running stage 2 with with zero mods, not even drop in filter, and their cars are running fine. But me on the other hand is different story lol. I also do oil change every 5K.

[mike@x-ph.com]

Originally Posted by m20e3087

Mike any updates on VRSF single mid for M2C? It's hard the get in touch with the VRSF ppl on the forum or insta. I was going to pull to trigger on AA but saw that VRSF started making one for S55 M3/M4, so decided to wait.

I dont not think VRSF has a set date yet on a release. I recommend checking with them direct for an ETA

[SinisterC6]

I have VRSF catless downpipes and a AA midpipe, it required cutting the OEM exhaust diffrently than what's instructed but it fits fine

Also used spacers on the O2 sensors and never had a CEL in 4k miles

[mike@x-ph.com]

Originally Posted by SinisterC6

I have VRSF catless downpipes and a AA midpipe, it required cutting the OEM exhaust diffrently than what's instructed but it fits fine

Also used spacers on the O2 sensors and never had a CEL in 4k miles

If you are using the midpipe with stock exhaust, you need to cut the stock exhaust (its all one piece from downpipe to muffler). If you are installing the midpipe with another aftermarket exhaust, no cutting is needed.

[BroDoze]

Whoa - I thought a tune or JB4 was absolutely mandatory to avoid CELs.

You can just add spacers? This will avoid CELs using both catless DPs and midpipe together?

[VIERsr]

Originally Posted by BroDoze

Whoa - I thought a tune or JB4 was absolutely mandatory to avoid CELs.

You can just add spacers? This will avoid CELs using both catless DPs and midpipe together?

If you replace primary cats (on downpipes), you need a tune to avoid CELs.
If you replace secondary cats (on mid pipe), you won't have any CEL.

[mike@x-ph.com]

Originally Posted by BroDoze

Whoa - I thought a tune or JB4 was absolutely mandatory to avoid CELs.

You can just add spacers? This will avoid CELs using both catless DPs and midpipe together?

Midpipe does not throw a code so no need for any tune or spacers

[brad65ford]

Wanted to update this thread for those that may be runing a similar setup as myself (BM3 stage 2 OTS 93, catless dp's and AA mid pipe). Well needless to say after driving with this setup for a few weeks now I didn't like it for multiple reasons. Mostly the drivablity. I like the volume of the sound but not when it releasing boost at part throttle from high boost. What I mainly was frustrated with was the spoil up was so quick it was near impossible to control partial fast acceleration at take offs to the point it was scary being uncontrollable. So yesterday I decided to removed the AA mid pipe and installed the stock mid pipe back on since I've never run the car with just DP's. Aside from the sound not being farty/blatty when stopping high boost, its night and day difference in controllable usable power "torque" down starts. Feels like its even stronger down stairs which could be all in my head, regardless its smoother tip in which I need to enjoy driving. Also ran just one dragy to compare 60-130 as well as 1/4 mph and the times where almost the same which made me even happier. So to cap this off, imo there is no need to do mid pipes if you have dp's which everyone suggested already in this thread and they were correct. What I'm surprised with is I still have some strong smell from the exhaust, not as bad but its still there, assuming those main cats do a lot for removing smell. Thank you for all that have listened and suggested. Currently loving the M2 Comp so much more now. Who would have though that an exhaust would make that much of a different in spoil up and throttle control. My guess is the shape change has a lot to do with it.