[flyknit]

I have bms intake, akrapovic exos and jb4 fitted (map 1).

Currently am thinking of getting bm3 and go with stage 2 OTS map. Would like to seek advise whether I should go with ER catted or catless and what sort of power gain I should expect coming from jb4.

Thanks

[topazalex]

Both the ER catted and catless downpipes are considered high flow and so would be appropriate for the stage 2 tune. Arguably the catless downpipes will sound better and will probably flow better but does lead to a distinct smell, and they are usually not permitted for road use.

As for the power gains, according to PTF peak power for stage 2 is between 420-430 bhp, however peak power shouldn't be the only reason for switching over to the map. Check the dedicated thread for the bm3, there are currently some mixed reviews and it is early days but the smoothness and improved throttle mapping seem to be the most praised aspects of the map.

[flyknit]

In dilemma whether to go catted or catless

[bmw22915]

Originally Posted by flyknit

In dilemma whether to go catted or catless

Catless downpipe going in on my car right now. Had a high flow cat earlier. I can give you my opinion later on the day once she's all done

[B58]

I originally had the 5" CG catted down-pipe and now i have the 4.5" VRSF cat-less down-pipe and i didn't feel much of a difference switching over. I do run 100% meth so i didn't want to ruin the high flow cat.

[Brett530]

Mine is a daily driver and I like quiet. I run a stage 2 (MG flasher) totally stock right now (91 with a little E85 mixed in). It makes great power; more than enough for lots of fun, and you have to be a special kind of demented to want more power in a daily driver. So, falling squarely into that category, I ordered a CG DS-1 high flow catted downpipe. I don't really want the extra noise & smell of a catless.

Originally Posted by B58

I originally had the 5" CG catted down-pipe and now i have the 4.5" VRSF cat-less down-pipe and i didn't feel much of a difference switching over. I do run 100% meth so i didn't want to ruin the high flow cat.

Tell me more about meth and catted. Would 50-70% meth harm a catted DP or was it just for more power? I know you really liked the CG DP.

[B58]

Originally Posted by Brett530

Mine is a daily driver and I like quiet. I run a stage 2 (MG flasher) totally stock right now (91 with a little E85 mixed in). It makes great power; more than enough for lots of fun, and you have to be a special kind of demented to want more power in a daily driver. So, falling squarely into that category, I ordered a CG DS-1 high flow catted downpipe. I don't really want the extra noise & smell of a catless.



Tell me more about meth and catted. Would 50-70% meth harm a catted DP or was it just for more power? I know you really liked the CG DP.

Oh I love the CG down-pipe. My daily driver has to be like 500rwhp so i just didn't want to risk burning the cat pushing a lot of boost and meth because the CG is not a down-pipe worth ruining. I'm currently @ 20 psi with JB4 and now with the MHD back end flash I'm probably going to try to dial it in around 21-22 psi and such and eventually switch over to a pure turbo.

[bacon_45]

400 WHP is not crazy fast. It's quick, but not fast. Let people build to whatever WHP goal they want, at the end of the day its their car. Calling someone "demented" is childish.

[Brett530]

Lighten up. It was a little humor - applied to myself. I was really referring to what my wife thinks of me when I accelerate into a corner. I think most readers on this forum find 400+ hp a starting point (especially in this B58 mods section).

[marcthedark]

Originally Posted by bacon_45

400 WHP is not crazy fast. It's quick, but not fast. Let people build to whatever WHP goal they want, at the end of the day its their car. Calling someone "demented" is childish.

Totally agree on the "demented" part, but if 400 WHP on a street car isn't fast but merely quick then I don't know a) where you are living that you can make use of all the hp b) how skillful of a driver you are or c) if you are just referring to a drag stip or other controlled environments when one can actually use WOT for more than a couple of seconds

[bacon_45]

I live in San Diego, a lot of open freeways. Traffic is only from 3-7, any other times you can go WOT pretty much anywhere.

[TreDirtyFive]

Originally Posted by bacon_45

400 WHP is not crazy fast. It's quick, but not fast. Let people build to whatever WHP goal they want, at the end of the day its their car. Calling someone "demented" is childish.

Ha..that is very subjective. That's almost 500hp crank and 90% of people in the world have never experienced that, better yet drive that on a daily basis. I'm not saying that's a pretentious & elitist comment but I'm a track guy and have driven 1000hp cars and still consider 400whp to be quite a bit. Different strokes.

[chenry]

IMHO once you start to pass that 400 WHP mark, assuming you are a typical driver without track experience, it's time for you to start to focus on your driving skills vs more power.

While I am no fan of big government (bold underline explanation point) and don't want govt intervention on this subject....it does surprise me that the silly DL you got as a teenager allows you to drive everything from a Prius to 1000hp+ car on a public street.

[G.Newt]

Originally Posted by Brett530

Mine is a daily driver and I like quiet. I run a stage 2 (MG flasher) totally stock right now (91 with a little E85 mixed in). It makes great power; more than enough for lots of fun, and you have to be a special kind of demented to want more power in a daily driver. So, falling squarely into that category, I ordered a CG DS-1 high flow catted downpipe. I don't really want the extra noise & smell of a catless.



Tell me more about meth and catted. Would 50-70% meth harm a catted DP or was it just for more power? I know you really liked the CG DP.

It's still fucking loud (when paired with a catback exhaust system) and still smells, but not too bad. If I've been driving it hard (like doing pulls on the highway) and then exit off and come to a stop light, I can smell it with my windows down. Nothing that I or any passenger in my car has ever commented on, however.

[Brett530]

Originally Posted by G.Newt

It's still fucking loud (when paired with a catback exhaust system) and still smells, but not too bad. If I've been driving it hard (like doing pulls on the highway) and then exit off and come to a stop light, I can smell it with my windows down. Nothing that I or any passenger in my car has ever commented on, however.

Not what I wanted to hear. I hope it will be tolerable with stock exhaust.

[G.Newt]

Originally Posted by Brett530

Not what I wanted to hear. I hope it will be tolerable with stock exhaust.

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.

[F3085258]

Just installed catless DP on weekend.

Cold start was crazy loud. Disabled via MHD.

I can faintly hear car in sport mode with windows up. In comfort sounds stock. With windows down it is a slight rumble. I need it louder yet.

As for smell. It is not that bad, even when it was started in my garage and It ran for a couple mins. This is my 5th catless car and one of the better in terms of smell.

[F3085258]

And If you find the smell too bad, you can buy a universal 100 cell cat for $100 and install. They flow well and that cut the smell out on my 2010 Wrangler with LS 5.3 V8 swap. It smelt pretty bad especially as it is a convertible.

[flyknit]

I’m leaning more towards catted now.. 😂

[BPAC306]

The CAT option for a stage 2 tune has been on my mind for a while now and I keep going back to the AFE cat...

https://afepower.com/afe-power-48-36...-street-series

Uses a 400 cell cat but is ceramic (like the factory) and not a steel mesh. I couldn't find much feedback on this for the B58. This cat should be free CEL and produce alot less smell since it is more restrictive than a typical 200 cell mesh cat. I'm reading the factory cat is 2 separate chamber ceramic @ 800 to 1000 cell count total

[G.Newt]

Originally Posted by BPAC306

The CAT option for a stage 2 tune has been on my mind for a while now and I keep going back to the AFE cat...

https://afepower.com/afe-power-48-36...-street-series

Uses a 400 cell cat but is ceramic (like the factory) and not a steel mesh. I couldn't find much feedback on this for the B58. This cat should be free CEL and produce alot less smell since it is more restrictive than a typical 200 cell mesh cat. I'm reading the factory cat is 2 separate chamber ceramic @ 800 to 1000 cell count total

I haven't seen that much feedback on AFE's catted DP, although it's about $150ish cheaper than CG DS-1's price right now. If their 200 cspi doesn't throw a CEL, that sounds like a very good deal. It'll help with smell a bit for sure.

[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