The Ultimate BimmerWorld Xpipe Solution

[MikeYQM]

Originally Posted by DanMpower

Thanks OP for the inspiration. I'll be making my own custom BimmerWorld X-Pipe solution as well.

Since I'm running a Stage 2 tune, not worried about a CEL so I'll be putting the GESI cats in your "resonated" position behind the X section and I'll be welding in some smaller resonators in the front position for a bit more clearance.

Dan, what resonators are you planning? I'm debating on the setup you described.

[Powashiftin]

OP: I have the catless BW x pipe and corsa mufflers. I only experience a very slight rasp around 2.5k RPM. When I say slight, it's for a second, if that. I'd like to hear your setup if you can post a video.

In my opinion, my setup sounds exactly as you described. Quiet around town. Loud when you need it to be. Very exotic up at higher rpm.

[dfwashere]

Originally Posted by kyippee

Can we get a sound video? I'm thinking about trying the Corsa muffler too. I have an Evolve HFC + resonated x-pipe, so I think it should be similar!

This. This is my exact setup as well but after what op posted, might be the route I go!

[dfwashere]

Originally Posted by Powashiftin

OP: I have the catless BW x pipe and corsa mufflers. I only experience a very slight rasp around 2.5k RPM. When I say slight, it's for a second, if that. I'd like to hear your setup if you can post a video.

In my opinion, my setup sounds exactly as you described. Quiet around town. Loud when you need it to be. Very exotic up at higher rpm.

Vids by chance? Thanks!

[gkgsvensson]

Sound video coming soon! Just have to get through a move and stuff, but I’d like to capture all situations.

1 week review:

I’m more addicted now than ever to the sound. However it’s not flawless. I just got a CEL (no biggie tho, going to tune anyway), and yes the cats stick out like ESS ones do. Wouldn’t recommend on a lowered car. No scrapes here however. Lastly, this setup is loud imo. When you’re cruising it’s very tame, somewhat boomy, but when you’re on it, everybody knows you’re coming. And I love that, it’s an M3 after all

[CTMike]

Originally Posted by gkgsvensson

I just got a CEL (no biggie tho, going to tune anyway),

This sounds kinda significant for folks looking for ultimate no CEL setup?

[GORDON.M3]

CEL is going to happen regardless of what x-pipe you get. Even with HFC.
The OEM cats are rated for 400CEL so its readings are far off compared to even a 300CEL setup. When getting any aftermarket x-pipe that replaces the factory cats you are going to have to tune it.

[DanMpower]

Originally Posted by MikeYQM

Dan, what resonators are you planning? I'm debating on the setup you described.

Mike, not sure yet but I know I want to keep the cats as far back in the system as possible, after the X so that the chances of them melting and ruining the engine is far less.

[Richbot]

Originally Posted by GORDON.M3

CEL is going to happen regardless of what x-pipe you get. Even with HFC.
The OEM cats are rated for 400CEL so its readings are far off compared to even a 300CEL setup. When getting any aftermarket x-pipe that replaces the factory cats you are going to have to tune it.

Not true. I've been running the aFe 300cell for 2.5 years without a single cat efficiency code, with all monitors enabled. To my eye, the aFe cat is about the same size as the GESi cats OP used. GESi also sells 300-cells that they market as "EPA Compliant" meaning they're, I assume, deemed to be just as efficient at cleaning exhaust gas as most OEM cats.

If it's doing that it's not going to gain near as much power as a 200-cell or catless setup, but the AFE does work, and does keep the CEL off on my car. I think the aFe might use a Magnaflow universal cat, or one from the same supplier, just looking at photos and how it's constructed.

Significantly, my car has a stage I Evolve tune, which does NOT impact cat readiness, and I opted to leave the cold start cycle in place.

[exVtekGuy]

Originally Posted by gkgsvensson

Sound video coming soon! Just have to get through a move and stuff, but I'd like to capture all situations.

1 week review:

I'm more addicted now than ever to the sound. However it's not flawless. I just got a CEL (no biggie tho, going to tune anyway), and yes the cats stick out like ESS ones do. Wouldn't recommend on a lowered car. No scrapes here however. Lastly, this setup is loud imo. When you're cruising it's very tame, somewhat boomy, but when you're on it, everybody knows you're coming. And I love that, it's an M3 after all

if you are going to get a tune to get rid of the cel, then it would have been better to place the cat further back I would think. I was told by my tuner that they don't recommend running stage 2 with a cat in primary position even if it's high flow. I am sticking with stage 1 with ess xpipe with hfc.

[GORDON.M3]

Originally Posted by Richbot

Not true. I've been running the aFe 300cell for 2.5 years without a single cat efficiency code, with all monitors enabled. To my eye, the aFe cat is about the same size as the GESi cats OP used. GESi also sells 300-cells that they market as "EPA Compliant" meaning they're, I assume, deemed to be just as efficient at cleaning exhaust gas as most OEM cats.

If it's doing that it's not going to gain near as much power as a 200-cell or catless setup, but the AFE does work, and does keep the CEL off on my car. I think the aFe might use a Magnaflow universal cat, or one from the same supplier, just looking at photos and how it's constructed.

Significantly, my car has a stage I Evolve tune, which does NOT impact cat readiness, and I opted to leave the cold start cycle in place.

Thanks for the clarification.

Ah I forgot the AFE option as they are the only one that has a 300 CEL setup.

Most have a 200CEL option in the primary position. I wouldn't personally run AFE HFC's after what has happened with SYT_Shadow's experience.

[AC/DC]

I have the aFe 300 cell cat setup and it's triggered a CEL before so I use a 45 degree elbow spacer and haven't had an issue since.

[MikeYQM]

OP: how is the cabin volume on the highway at about 70-75 mph?

[SYT_Shadow]

Originally Posted by GORDON.M3

Most have a 200CEL option in the primary position. I wouldn't personally run AFE HFC's after what has happened with SYT_Shadow's experience.

Yup... you won't see me running a HFC in the primary position anytime soon!

[gkgsvensson]

Originally Posted by MikeYQM

OP: how is the cabin volume on the highway at about 70-75 mph?

It’s definitely noticeable with windows up and music off. It’s at the bleeding edge of what a picky exhaust person would consider a little too much. It’s the same amount of sound as a stock x pipe + Corsa plus a tiny bit more at that speed. However I’ve never heard an exhaust that is as quiet as oem in cabin

[MikeYQM]

Can everyone who has had the 2500 RPM torque dip/bog/hesitation please reply and provide the following information?

- X-Pipe Type:
- Axle Back Exhaust Type:
- Tune:


I'm trying to collect some stats to help direct our research into this issue.

[spliffin]

Can we get a video please? I'd love to hear the exhaust note. I'm running the full Bomiz valved system and am looking to change up.

[aus]

Originally Posted by SYT_Shadow

Whenever I talk with James or Phil at BW I always nag them for not building the regular header version with a gesi cat.
They do make this for their longtube headers. I have those headers in my stroker and have both the uncatted and catted xpipes

Losing the engine was sad and had led to an impressive cost over the last few years, but the stroker is quite awesome.

The Bimmerworld xpipe is absolutely the way to go. With these improvements you've made it's a no brainer for me. Great job executing it and posting your results!

You're blown motor was from fowled aftermarket cats???
Damn, I must have fallen off the thread.
Makes me nervous about aftermarket cats then!
Though My buddy's stock X-Pipe primary cats got ruined too.
.

[SYT_Shadow]

Originally Posted by aus

You're blown motor was from fowled aftermarket cats???
Damn, I must have fallen off the thread.
Makes me nervous about aftermarket cats then!
Though My buddy's stock X-Pipe primary cats got ruined too.
.

I think the key message is you shouldn't be running primary cats if you are tracking the car hard.

Most people now are getting the cats welded in after the X, so they're further downstream and shouldn't be a problem.

[aus]

Originally Posted by SYT_Shadow

I think the key message is you shouldn't be running primary cats if you are tracking the car hard.

Most people now are getting the cats welded in after the X, so they're further downstream and shouldn't be a problem.

Thanks!
My buddy was all stock and his primary cats got fowled up.
We track 3-5 weekends a year.
So the secondary cats are at risk if you track?
Thanks!
.

[SYT_Shadow]

Originally Posted by aus

Thanks!
My buddy was all stock and his primary cats got fowled up.
We track 3-5 weekends a year.
So the secondary cats are at risk if you track?
Thanks!
.

I haven't heard of anyone messing up secondary cats by tracking the car. I wouldn't worry

[accarter]

10 years dungeon for not posting a video OP. Your description sounds absolutely delicious