Stett Performance Vacuum Canister Review

[matreyia]

I just replaced my stock canisters with the Stett Performance Steel canisters. Here are my impressions.

1. Looks Very Good.
2. Throttle response is razor sharp compared to stock canisters and BOV has higher sensitivity to even slightest change of pedal. I would say the "resolution" of the BOV has increased such that it will also do super tiny poooosh poooshes in direct reaction to tiny pedal input. Previously, it would only do gross level single big pooooshes...So this is a startling change.
3. When used with Vader BOV Adapter, the combination is perfect... just so freaking accurate on boost levels. The car just feels rock solid all thru acceleration without the slightest dip in power.

The car feels faster now, not because there was more power increase, but rather because most or all of the power is now able to be harnessed without even a tiny amount of boost leaking.

Do I recommended this? ABSOLUTELY YES. I would buy these again if I had another n54.

VT

 

[doublespaces]

I just replaced my stock canisters with the Stett Performance Steel canisters. Here are my impressions.

1. Looks Very Good.
2. Throttle response is razor sharp compared to stock canisters and BOV has higher sensitivity to even slightest change of pedal. I would say the "resolution" of the BOV has increased such that it will also do super tiny poooosh poooshes in direct reaction to tiny pedal input. Previously, it would only do gross level single big pooooshes...So this is a startling change.
3. When used with Vader BOV Adapter, the combination is perfect... just so freaking accurate on boost levels. The car just feels rock solid all thru acceleration without the slightest dip in power.

The car feels faster now, not because there was more power increase, but rather because most or all of the power is now able to be harnessed without even a tiny amount of boost leaking.

Do I recommended this? ABSOLUTELY YES. I would buy these again if I had another n54.

VT

If I remember correctly, the vacuum canisters supply backup suction to the wastegates to allow the turbo to build boost (it has no connection to the intake manifold). Having a stronger vacuum signal would mean your turbos may build boost faster when pressing the throttle. However those canisters are a vacuum reservoir, I don't believe they actually increase the vacuum as they are just there for situations when the mechanical vacuum pump may not produce enough vacuum for one reason or another such as brake booster hogging the vacuum at low rpms.

So if you're experiencing this, then you probably had a leaking vacuum canister or vacuum line from the pump to the wastegates and you'd experience the same thing with no vacuum canisters at all so long as your vacuum pump was healthy and the vacuum leak/issue was addressed.

 

[matreyia]

If I remember correctly, the vacuum canisters supply backup suction to the wastegates to allow the turbo to build boost (it has no connection to the intake manifold). Having a stronger vacuum signal would mean your turbos may build boost faster when pressing the throttle. However those canisters are a vacuum reservoir, I don't believe they actually increase the vacuum as they are just there for situations when the mechanical vacuum pump may not produce enough vacuum for one reason or another such as brake booster hogging the vacuum at low rpms.

So if you're experiencing this, then you probably had a leaking vacuum canister or vacuum line from the pump to the wastegates and you'd experience the same thing with no vacuum canisters at all so long as your vacuum pump was healthy and the vacuum leak/issue was addressed.

You remember correctly. They are reservoirs.

 

[veer90]

The vacuum canisters were designed with spirited driving in mind, where you're repeatedly smashing the brakes then the gas quickly in succession. With a reservoir more vacuum is available to the wastegates immediately after hard braking.

Many people delete them with no issue since they only do highway pulls.

 

[matreyia]

The vacuum canisters were designed with spirited driving in mind, where you're repeatedly smashing the brakes then the gas quickly in succession. With a reservoir more vacuum is available to the wastegates immediately after hard braking.

Many people delete them with no issue since they only do highway pulls.

Yep, I did this test after installing and never felt any momentary loss of boost during repeated mashing of brakes and acceleration. It's mind boggling how consistent the car is in power delivery now.

 

[Mikejones1208]

What these people are trying to say is that those aftermarket vac canisters do nothing for you aside from look nice in the engine bay, if you noticed a difference after changing them out then your old ones were probably busted and leaking vacuum

 

[matreyia]

What these people are trying to say is that those aftermarket vac canisters do nothing for you aside from look nice in the engine bay, if you noticed a difference after changing them out then your old ones were probably busted and leaking vacuum

If I were you, I would read more carefully. Also do your research on why the canisters are there. No, you don't have to have them. But if you do, they provide a backup cushion for harsh stop and go driving without loss of vacuum from repeated braking and acceleration. Most of my driving is exactly that.

And btw, my plastic canisters were almost brand new and there was still a noticeable improvement. That leads me to believe the plastic are just not made that well.

 

[Mikejones1208]

I understand that what im saying is the stock ones if in good condition and not leaking do just that with no problem

 

[Mikejones1208]

I didnt say anything regarding getting rid of them, they have a purpose, but the stett ones do not give you any type of performance increase aside from not breaking as easily as the stock plastic ones

 

[matreyia]

I didnt say anything regarding getting rid of them, they have a purpose, but the stett ones do not give you any type of performance increase aside from not breaking as easily as the stock plastic ones

And that is why I replaced them. It is both a preventive maintenance as well as absolute certainty that I will not have any leaking canisters. If you are fine with your plastic canisters and you think they are good enough and you know they are not leaking, then more power to you. As it stand now, I KNOW my canisters are not leaking due to upgraded hoses, clamps at the nipples and nearly indestructible stainless steel canisters. And I can feel a noticeable difference in throttle response time. That's after replace my almost new plastic canisters. So take this report however you like. I am only reporting my own findings on my car.

 

[Asbjorn]

One of my canisters melted on track after swapping to the hotter GC manifolds (Note Z4 canister placement is different form 1/3-series). These would have prevented that, but then again, moving the OEM canisters a bit away from the manifolds also solves the problem.

Is there any data to support the the capacity of these are higher than the OEM canisters?

 

[matreyia]

One of my canisters melted on track after swapping to the hotter GC manifolds (Note Z4 canister placement is different form 1/3-series). These would have prevented that, but then again, moving the OEM canisters a bit away from the manifolds also solves the problem.

Is there any data to support the the capacity of these are higher than the OEM canisters?

I think they are exactly the same volume as stock. everything is identical except for they are metal and do not leak if you use hose clamps on the nipples.

 

[nissubaru]

Is there any data to support the the capacity of these are higher than the OEM canisters?

Doubt it. I don't think there's any data to even support a need for OEM canisters let alone for larger canisters and their perceived benefit (whatever that is). My car has no canisters either and I have never noticed anything.

 

[martymil]

I have a set of these on my car and they look good, are unbreakable and if they weren't needed why did bmw put them there.

If you don't want them don't use them but these are a great alternative to the weak oem versions if you do.

Ive seen so many broken ones come in to the my mates shop over the last 3 years, its crazy.

I actually made my own now which is hidden under the manifold, buts that's another thread coming soon.

 

[matreyia]

I have a set of these on my car and they look good, are unbreakable and if they weren't needed why did bmw put them there.

If you don't want them don't use them but these are a great alternative to the weak oem versions if you do.

Ive seen so many broken ones come in to the my mates shop over the last 3 years, its crazy.

I actually made my own now which is hidden under the manifold, buts that's another thread coming soon.

I tell you what, there are many folks who assume they know better than the makers in some cases. For example, they get rid of canisters, and see no change..so they assume it was useless. Not once thinking how illogical it would be for the companies to make extra parts for literally nothing. Because we all know how companies are just itching to add in costs to they products right?

Whatever, let the armchair engineers do as they please.

There are two approaches...
1. Improve on a design that clearly cuts corners by creating one with better materials.

2. Delete the item completely because you don't see a difference or don't know what it's for.

I chose option 1.

 

[SlowE93]

I tell you what, there are many folks who assume they know better than the makers in some cases. For example, they get rid of canisters, and see no change..so they assume it was useless. Not once thinking how illogical it would be for the companies to make extra parts for literally nothing. Because we all know how companies are just itching to add in costs to they products right?

Whatever, let the armchair engineers do as they please.

There are two approaches...
1. Improve on a design that clearly cuts corners by creating one with better materials.

2. Delete the item completely because you don't see a difference or don't know what it's for.

I chose option 1.

Vacuum reservoirs are used for many applications / cars. I had an 82 oldsmobile. It had a reservoir that connected to the a/c unit (it actually controlled the flaps for a/c, heater, recirculate air, etc). A line unplugged from it one day. I immediately noticed as I would accelerate, my a/c would blow less air. Once vacuum built up again, everthing worked fine. Dead stop and accelerated again, flaps were closing and the air was being redirected to the upper dash / defrost which is why I felt my a/c going out. I pull over, find the line came undone, plugged it back in and everything worked flawlessly again. So in my case, it worked either way, just not as intended or properly. My .02c vacuum reservoirs are there for a reason. They are in place to assure proper vacuum at all times under different situations.

 

[Mikejones1208]

Again your not reading what i said. Im not saying to delete them, im saying this "razor sharp throttle response" your speaking of is nothing more then a placebo effect. The stock canisters if in good condition do their job just fine, "upgrading" to the stett cannisters yield absolutely no real performance increase even if they do hold more vacuum. The only benefit you get from them is that they are less likely to fail, your the only one here spreading false information. Like previously stated by me and other posts, if you noticed a difference in driveability then your factory ones were most likely leaking or defective. Have you looked inside one of those before? Theres literally nothing. Its just an empty space with an opening on each end, which is all that is needed for stagnant vacuum. It doesnt need a smooth flowing can nor more volume. It just doesnt need to leak

 

[martymil]

Actually there is a small benefit as the inlet and outlet on the canisters are slightly bigger thus letting more volume of vacuum flow to the solenoids which would snap the turbos slightly faster and giving slightly more initial boost and slightly better throttle response.

Such a small difference would be unmeasurable but more likely felt, you would have to have extra sensitive senses to notice the difference but it would be there.

I personally have not noticed any difference myself, but hell better sturdy metal and unbreakable cans than crappy brittle old plastic.

 

[matreyia]

Again your not reading what i said. Im not saying to delete them, im saying this "razor sharp throttle response" your speaking of is nothing more then a placebo effect. The stock canisters if in good condition do their job just fine, "upgrading" to the stett cannisters yield absolutely no real performance increase even if they do hold more vacuum. The only benefit you get from them is that they are less likely to fail, your the only one here spreading false information. Like previously stated by me and other posts, if you noticed a difference in driveability then your factory ones were most likely leaking or defective. Have you looked inside one of those before? Theres literally nothing. Its just an empty space with an opening on each end, which is all that is needed for stagnant vacuum. It doesnt need a smooth flowing can nor more volume. It just doesnt need to leak

You know nothing about my car. There was no placebo effect. The throttle response definitely became sharper. Not due to the canister being inherently better than the plastic version in any secret way but due to the fact that it had zero leaks vs. The plastic ones which were less than a year old. I am well aware of the contents of the plastic empty canisters. You keep wanting to discount my report... go ahead, but don't misread my reviews.

The canisters are simply leak proof and that is why I had better response. No magic, no secret sauce.

People come to reviews with their know it all attitudes trying to talk down positive reports... "oh l, it's just placebo..." or "oh, it's only because your old canisters were leaking..." Well no shit they were leaking. That's the whole point of getting metal ones. I did not want to delete the stock design but wanted peace of mind so I upgraded to indestructible canisters. Just so happens the upgrade yielded improvements I noticed. I did not expect to feel any improvement, but I did... end of story.

Finally, you're the one who says that it is deletable and I am the one saying don't delete the design but just upgrade and keep factory setup... and you are saying that I am spreading false information? I am not the one that even considers deleting a factory design just because I see no effect. You think they decided to add two items because they wanted to spend more on production??? Wtf?

 

[fmorelli]

Actually there is a small benefit as the inlet and outlet on the canisters are slightly bigger thus letting more volume of vacuum flow to the solenoids which would snap the turbos slightly faster and giving slightly more initial boost and slightly better throttle response.

May I ask, if the inlet at the solenoid entry is a fixed size, how is making any upstream orifices larger going to change what the solenoid actually sees, vacuum-wise? Not sure I understood this. Just as an anecdotal observation, I would be surprised if BMW designed the vacuum system so that it had insufficient vacuum to operate the two solenoids. Or am I completely misunderstanding what you're saying, @martymil ?

Filippo