Justins17c43

Hey guys, so I know there’s threads with these but I’m looking for something overly specific lol. Currently I have a bms intake with jb4 and stock non-pe exhaust. My question is, if I do catted downpipes will I see any gain in performance/sound? The ones I’m looking at are $1200 so I really want to be sure it’s worth it. Thanks in advance guys

BMS

I don't think there is enough of a performance benefit to justify the cost, no less the emissions non-compliance.

Justins17c43

so I was going to do the spacers for the sensors so it wouldn’t code out, I really want some more noticeable power out of it and I’d love just a touch more sound. Like if it sounded how it sounds on a cold start that would be amazing I don’t want it to be obnoxious. I’m currently running map one on the jb4 what would be my next best mod to get me a lot more horsepower?

0dte

If you don't have the PE, the money is better spent on an exhaust system first. For noticeable power, you'll need a stage 2 tune to accompany the downpipes. Try running Map 3 if you want a little more kick.

Howyalivin

After a tune, or a JB4, there are no easy mods that make "A lot more power". Forget the DP, work on moving from map 1 to map 2, or even beyond. That's where a lot of power is going to come from. What is stopping you from going beyond map 1 right now? I ask that because you want to spend $1200 for something that gives very little gain, but are ignoring a mod you already have that still has between a half of a second to a full second left in it, if you learn how to tune your car. You have free horsepower waiting for you to understand your platform and you're looking to spend over a grand on something new for a tenth. Why? It seems like you're eager to make power, but not as eager to figure out what your car is all about, which is likely to end with broken parts.

DemonC63s

Hey Downpipes whether they are sport catted or catless have higher flow there will be gains mostly used for sound increase. If u can stand the gas smell I would say go cat less for biggest sound tone increase, but sport cats will make a huge difference as well with a lot less gas smell hope that helps. Looking at installing a similar setup on mine already have the parts on hand. Eurocharged quoted $1500 for installation not sure if other shops have better prices 11 hour labour was quoted due to the turbos placement in the hot v, note (requires transmission removal) to do it properly without cutting cats W205 C63s sedan by the way. $1200 Usd? are they even heat shielded I would check out the options as this this affects under hood temps without the shields quite a bit, especially if you are deciding to do further mods down the line.

Justins17c43

I haven't done map 2 or 3 yet because I'm honestly not sure what needs to be done (besides obviously changing to it in the app) I'm getting a lot more air flow in with the intakes and I was worried about leaning out. Also thought I needed at least downpipes for map 3 but might be mistaken? I unfortunately bought my jb4 second hand and initially when I contacted bms (I had an update issue) they don't support it unless I bought it new from them. If anyone has ANY info on the jb4 I will absolutely take it lol

MaverickC43

I can kind of understand bms if they didn’t want to fix/replace unit Bc 2nd hand, but they should still help with updates & firmware.
I think I’ve seen them say that “you can always resell your Jb4”

SilverBullet18

Me, my brother in law and my co-worker all have C43's and 1 c450.

By far the best sound mod you can do thats also a power mod is catted downpipes (note I say catted NOT -catless). Catless pipes just sound grainy at the upper mid range and the headache smells are not worth the 1 to 3 HP that you will never feel vs catted.

as an acoustical enhancement paired with the upgraded tune to accompany them, in my opinion and others: they are worth it. my brother in law did the catted downpipes and the "bmw back box mod" on his Non-PE exhaust and it sounds delicious. its not the kick in your butt improvement like when you went stage 1 but its an improvement all over the rev range and the throttle response and extra spool up are definite pluses.


All 3 of us are running 02 spacers and are CEL free collectively for about 5000+ miles combined.

Howyalivin

Justin, spend more time learning about tuning the JB4. It's not an insult, just slow down. You just got the car, and you want to slap everything on, without understanding any of it. DPs, catless, DP's, can't work with a JB4. You need to spend more time on this forum, studying the info on JB4's. Also, learn about octane, and what each map on the JB4 will take. I've made a couple of posts on it, so follow that sort of thing. Download logs, post them up for BMS to read, follow advice, and your car will rip. Ignore all of that, and you'll have parts issues. You seem to be young and/or inexperienced. There's no shame in that, all of us were at one time. Consider it like Luke wanting to know everything right now and Yoda or Obi telling him that it takes time and effort. Your questions show you don't know the platform you own, and that you don't understand the mods, even the ones you own. Slow down. You have a lot more in the parts and the platform you already have, you just haven't taken the time to learn.

MaverickC43

there’s a lot of guys on here with Jb4.
just not always checking each thread.
herrera is a guy who I will be talking to when I get mine.
but just send some pm and I bet you’ll get help. I know nothing about actually having one but if u get a ****ty response from a guy ask someone else.

BMS

While used units don't qualify for support email or warranty you're always welcome to use the n54tech support forum to post logs, ask questions, and seek assistance.

Map guide is based on octane, nothing to do with exhaust mods.