[Fuji]

Originally Posted by Yournamehere90

He's read posts where people have excluded the canisters but connected the rest as it was originally. Basically the solenoids and actuators still receive vacuum but they don't have the reservoirs there to store vacuum pressure. To be honest I'm not sure why they are needed. Because that side of the system is run by a vacuum pump, I would expect that they always have the required vacuum to run the wastegates. The canisters may also be a reason for wastegate rattle during startup as they provide more volume to be evacuated and would slow down the closing of the wastegates, causing rattle. That last part is just speculation though. I haven't tried it.

Yeah that makes sense. I find I get WG rattle on cold start up and it's due to exactly what you've outlined. I replaced the brake check valve and associated grommet today and I think it eliminated/ significantly reduced my WG rattle rattle on start up. The vacuum was leaking through the check valve and thus the WG had further to travel upon restarting the car.

Apparently it's a pretty common issue and something worth looking into if your brake pedal goes hard first thing in the morning or after letting it sit for a few hours

[JustDriveIt]

Originally Posted by Yournamehere90

He's read posts where people have excluded the canisters but connected the rest as it was originally. Basically the solenoids and actuators still receive vacuum but they don't have the reservoirs there to store vacuum pressure. To be honest I'm not sure why they are needed. Because that side of the system is run by a vacuum pump, I would expect that they always have the required vacuum to run the wastegates. The canisters may also be a reason for wastegate rattle during startup as they provide more volume to be evacuated and would slow down the closing of the wastegates, causing rattle. That last part is just speculation though. I haven't tried it.

The canister volume really does not make a difference and you wouldn't be able to tell the difference if you were to exclude it (thanks to Boyle's law).
HOWEVER - many people have leaks in their canisters that they are unaware of (myself included) and so when they bypass it they get an improvement and associate this improvement with the exclusion of the canister, when it would have been the same improvement if they just replaced it or fixed it.

[89mustaine]

Originally Posted by JustDriveIt

The canister volume really does not make a difference and you wouldn't be able to tell the difference if you were to exclude it (thanks to Boyle's law).
HOWEVER - many people have leaks in their canisters that they are unaware of (myself included) and so when they bypass it they get an improvement and associate this improvement with the exclusion of the canister, when it would have been the same improvement if they just replaced it or fixed it.

So can anyone make an argument for why these canisters exist in the first place? I'm about to go rip them out right now, might as well free up some space in there...

[bpdef29]

Running rattle fix with the wastegates as open as possible on MHD definitely makes a big difference in exhaust volume with DPs (especially with respect to gurgles/pops). I've played with it a bit. The loss in drivability isn't supplemented with the newfound sound though. The increased lag is substantial.

Canister bypass would only decrease volume if the canisters had a leak and wouldn't affect volume without a leak, as stated above.

Unplugged WG lines and rattle fix are definitely not permanent solutions to more sound.

[tofu?]

Originally Posted by 89mustaine

So can anyone make an argument for why these canisters exist in the first place? I'm about to go rip them out right now, might as well free up some space in there...

Buffer

[89mustaine]

Originally Posted by tofu?

Buffer

I guess I should have asked for an explanation rather than an argument, that technically counts.....

[J. Dub]

Originally Posted by 89mustaine

So can anyone make an argument for why these canisters exist in the first place? I'm about to go rip them out right now, might as well free up some space in there...

No argument here. I took my cans off today. No change in driveability or in my monitoring with mhd / logs.

[J. Dub]

Originally Posted by JustDriveIt

The canister volume really does not make a difference and you wouldn't be able to tell the difference if you were to exclude it (thanks to Boyle's law).
HOWEVER - many people have leaks in their canisters that they are unaware of (myself included) and so when they bypass it they get an improvement and associate this improvement with the exclusion of the canister, when it would have been the same improvement if they just replaced it or fixed it.

But why replace or fix them when you can clean up your engine bay and remove them all together. Twisted tuning (a n54 custom tuner) also removed his canisters with no ill effects.

[sloweste9x]

Originally Posted by J. Dub

But why replace or fix them when you can clean up your engine bay and remove them all together. Twisted tuning (a n54 custom tuner) also removed his canisters with no ill effects.

Is there a DIY for removing them? I'd love to and maybe it would solve some of my boost issues

[tofu?]

can you make a new thread for that?

rather hear about updates on fuel cutoff tables

[7smurfs]

Originally Posted by tofu?

can you make a new thread for that?

rather hear about updates on fuel cutoff tables

Agreed! Eagerly awaiting further updates

[JustDriveIt]

Originally Posted by 89mustaine

So can anyone make an argument for why these canisters exist in the first place? I'm about to go rip them out right now, might as well free up some space in there...

You can think of it like a capacitor for a large amp/subwoofer. It's only supplying 12v but it can store some charge for when you need a massive amount immediately for a split second.

I suppose the thinking is to increase response time - holding a vacuum "charge" allows the wastegates to shut quicker instead of waiting a few split seconds for it to acquire the vacuum it needs. I doubt anyone ever notices a difference, but there is one.

[TrollToll]

Originally Posted by JustDriveIt

You can think of it like a capacitor for a large amp/subwoofer. It's only supplying 12v but it can store some charge for when you need a massive amount immediately for a split second.

I suppose the thinking is to increase response time - holding a vacuum "charge" allows the wastegates to shut quicker instead of waiting a few split seconds for it to acquire the vacuum it needs. I doubt anyone ever notices a difference, but there is one.

The actuators vent to atmosphere when they need to release vacuum quickly, so at certain duty cycles they probably bleed pretty quickly. The canisters would provide a steady supply. However, as several people have mentioned, they have been running without them. Maybe it's just another example of BMW over-engineering.

[89mustaine]

Originally Posted by JustDriveIt

You can think of it like a capacitor for a large amp/subwoofer. It's only supplying 12v but it can store some charge for when you need a massive amount immediately for a split second.

I suppose the thinking is to increase response time - holding a vacuum "charge" allows the wastegates to shut quicker instead of waiting a few split seconds for it to acquire the vacuum it needs. I doubt anyone ever notices a difference, but there is one.

Originally Posted by Yournamehere90

The actuators vent to atmosphere when they need to release vacuum quickly, so at certain duty cycles they probably bleed pretty quickly. The canisters would provide a steady supply. However, as several people have mentioned, they have been running without them. Maybe it's just another example of BMW over-engineering.

Well that all makes sense. Thanks for the explanation. If the operate as a kind of capacitor meaning the vacuum pump is the battery/alternator, does removing them put more strain on the pump or lines? I like the idea of cleaning up the engine bay and taking them out but I don't see an up side to taking them out other than that.

[JustDriveIt]

Originally Posted by 89mustaine

Well that all makes sense. Thanks for the explanation. If the operate as a kind of capacitor meaning the vacuum pump is the battery/alternator, does removing them put more strain on the pump or lines? I like the idea of cleaning up the engine bay and taking them out but I don't see an up side to taking them out other than that.

It wouldn't put more strain on the system, but like it was stated above, since these solenoids vent to atmosphere and are run on a duty cycle frequency, they do bleed over time and the reservoir would help it maintain this level of vacuum "quicker" and slow the vacuum "draining" if it ever gets to that point. My guess is it just makes it slightly quicker to build pressure at the actuator (post-solenoid).

I did some testing on my own. Pre and post reservoir so simulating with and without and pressure built slightly faster post reservoir - but I doubt it would be enough to make a difference. I'll try to make a video so we can have objective data and can look at the actual timing.

[jyamona]

Holy thread derail, batman. Just perfecting this before release. Stay tuned

[TGNY 335]

Guys, please make another thread for the Vac Canister Talk, thanks. im not a moderator or anything, but I hate seeing threads derailed.

Great job as always Jake. Let me know if you need anything.

[Supra2k6]

Originally Posted by jyamona

Holy thread derail, batman. Just perfecting this before release. Stay tuned

Seriously cannot wait, still need/want a custom tune tho

[89mustaine]

Originally Posted by TGNY 335

Guys, please make another thread for the Vac Canister Talk, thanks. im not a moderator or anything, but I hate seeing threads derailed.

Great job as always Jake. Let me know if you need anything.

Originally Posted by jyamona

Holy thread derail, batman. Just perfecting this before release. Stay tuned

Haha sorry, pretty sure that conversation is over, just trying to kill some time while we wait for this tune to be perfected.

[tofu?]

Originally Posted by jyamona

Holy thread derail, batman. Just perfecting this before release. Stay tuned

Tease us with a test video

[SlimE92]

Originally Posted by tofu?

Tease us with a test video

+1

Originally Posted by tofu?

Tease us with a test video

How about teasing him with a donation for all his hard work first.