[midnight.240i]

Been thinking about getting my center section of the exhaust removed so its a straight pipe flowing into a twin pipe from the downpipe to the back box.

I've been to a reputable company who did the inspection and couldn't guarantee the car wouldn't go into limp mode because of the change in exhaust pressure etc. and the car being basically brand new. its a 2024 240i xdrive with all the new interior, new software...

Has anyone done this yet? did they have any issues? I don't want to map the car or do anything else really power wise just wanting a bit more noise...

UK spec car also for info

Any help is much appreciated

Thanks

[Pentland]

Don’t know the answer to your question but that exhaust part is described as “ RP Gas.particulate Filter W.front Pipe”. *If* it contains the filter, removing it is illegal.

My only question would be why?

[MPR]

Originally Posted by Pentland

Don’t know the answer to your question but that exhaust part is described as “ RP Gas.particulate Filter W.front Pipe”. *If* it contains the filter, removing it is illegal.

My only question would be why?

Taking a shot in the dark here but my guess is sound + flow improvement.

[midnight.240i]

Originally Posted by MPR

Taking a shot in the dark here but my guess is sound + flow improvement.

Exactly that mate, Just want to make sure the car isn't going to go into limp mode if i take the centre section out of the exhaust as marked in the drawing above?

I know some people have tried using a an mil sensor to trick the ecu into thinking it still there but have seen some other places can still make the car go into limp mode without a map

[NKiss]

interested in seeing the follow up!

[BIGW0RM]

Sounds like a typically custom made midpipe to me. Which in the M2, it will not throw a code. So I dont see why it would on a M240I but dont take my word for it. I have no 240i experience.

[Pentland]

Originally Posted by MPR

Taking a shot in the dark here but my guess is sound + flow improvement.

You’ve missed my point.
Does this part have the GPF? If so, it’s illegal to remove so why do it?

[MPR]

Originally Posted by Pentland

You’ve missed my point.
Does this part have the GPF? If so, it’s illegal to remove so why do it?

When have laws ever stopped someone from doing mods? I thought you were truly after his intent.

[Pentland]

Originally Posted by MPR

When have laws ever stopped someone from doing mods? I thought you were truly after his intent.

It may not stop him doing the mod but if the GPF is removed, he won’t pass his MoT. He’ll also be uninsured as he won’t be driving a roadworthy vehicle.

[ILikeBimmers]

Originally Posted by midnight.240i

Been thinking about getting my center section of the exhaust removed so its a straight pipe flowing... I don't want to map the car or do anything else really power wise just wanting a bit more noise...

...UK spec car...

If you're just looking for a bit more noise, I think a high flow downpipe (Active Autowerks) and a performance axel back muffler (Dinan, MPE, etc., hell even a muffler delete) is going to be more bang for your buck. Blasting out your entire midpipe seems extreme, and without a FEMTO tune I'd really question what kind of gains you'd get anyway.

Without doing any kind of research, modifying back pressure may lead to worse engine performance in certain cases. BMW has likely optimized backpressure to some extent and you may not want to dramatically mess with this unless you understand the change you're making. This is something you need to consider.

This is, of course, ignoring that you're in the UK which, if I'm not mistaken, already comes with a lower emissions version of the US variant. Tighter emissions in the UK doesn't change the above advice.

For the sake of dollar efficacy and not dealing with possible limp mode you can't tune out due to post 2020 DME lock, I would just go with a down pipe and axel back modification as this is going to orders of magnitude easier to deal with and for which tons of documented experiences exists. Granted I've seen documented experience of mid pipe replacements on F series m240s without any consideration for limp mode activation, so maybe it's just your exhaust mechanic trying to cover their ass.

If that isn't enough sound for you there's always the infamous obnoxious maxed out popcorn/snare drum tune where you FEMTO unlock and slide your fuel over-run time window all the way to the right.. which all I can advise in that case is "enjoy responsibly" and consider how much your neighbors will hate you at 6 AM.

[midnight.240i]

Originally Posted by ILikeBimmers

If you're just looking for a bit more noise, I think a high flow downpipe (Active Autowerks) and a performance axel back muffler (Dinan, MPE, etc., hell even a muffler delete) is going to be more bang for your buck. Blasting out your entire midpipe seems extreme, and without a FEMTO tune I'd really question what kind of gains you'd get anyway.

Without doing any kind of research, modifying back pressure may lead to worse engine performance in certain cases. BMW has likely optimized backpressure to some extent and you may not want to dramatically mess with this unless you understand the change you're making. This is something you need to consider.

This is, of course, ignoring that you're in the UK which, if I'm not mistaken, already comes with a lower emissions version of the US variant. Tighter emissions in the UK doesn't change the above advice.

For the sake of dollar efficacy and not dealing with possible limp mode you can't tune out due to post 2020 DME lock, I would just go with a down pipe and axel back modification as this is going to orders of magnitude easier to deal with and for which tons of documented experiences exists. Granted I've seen documented experience of mid pipe replacements on F series m240s without any consideration for limp mode activation, so maybe it's just your exhaust mechanic trying to cover their ass.

If that isn't enough sound for you there's always the infamous obnoxious maxed out popcorn/snare drum tune where you FEMTO unlock and slide your fuel over-run time window all the way to the right.. which all I can advise in that case is "enjoy responsibly" and consider how much your neighbors will hate you at 6 AM.

Much Appreciated for the info mate, I'll have a think about things going forward then as I'm not looking to map the car or get that extra performance until the warranty is done anyways it was purely for a little more noise so I think i'll be going for a back box delete in that case which hopefully shouldn't put the car into limp mode and leave the PPF etc alone for now...

But thanks for all the advice guys!

[ILikeBimmers]

Originally Posted by midnight.240i

Much Appreciated for the info mate, I'll have a think about things going forward then as I'm not looking to map the car or get that extra performance until the warranty is done anyways it was purely for a little more noise so I think i'll be going for a back box delete in that case which hopefully shouldn't put the car into limp mode and leave the PPF etc alone for now...

But thanks for all the advice guys!

A muffler delete will not activate limp mode. With the exhaust flap open the car is pretty close to a muffler delete tbh. While the car won't sound bad, I think the muffler delete makes it sound too airy.

If you purchase the M performance exhaust it won't effect your warranty despite your muffler being saws off at the axels. Some other members were mentioning dinan, miltek, etc. doesn't effect warranty either, but the MPE is the only one I know for sure that won't effect it.

You muffler should not have any effect on emissions or filtering. It is for sound, only.

[Pentland]

Originally Posted by ILikeBimmers

A muffler delete will not activate limp mode. With the exhaust flap open the car is pretty close to a muffler delete tbh. While the car won't sound bad, I think the muffler delete makes it sound too airy.

If you purchase the M performance exhaust it won't effect your warranty despite your muffler being saws off at the axels. Some other members were mentioning dinan, miltek, etc. doesn't effect warranty either, but the MPE is the only one I know for sure that won't effect it.

You muffler should not have any effect on emissions or filtering. It is for sound, only.

MPE is not available in the UK, probably due to noise or emissions.
However, cannockwolf imported one.

[ILikeBimmers]

Originally Posted by Pentland

MPE is not available in the UK, probably due to noise or emissions.
However, cannockwolf imported one.

You're right I totally forgot about that. UK gets the stricter gas particulate filters and no MPE.

[felixlamb]

GPF delete cable, and gut the GPFs if you absolutely want to. That way they're physically there and will pass a visual inspection.

[Pentland]

Originally Posted by felixlamb

GPF delete cable, and gut the GPFs if you absolutely want to. That way they're physically there and will pass a visual inspection.

Why even suggest that?