Catch can fab

N54gasm

Sergeant
Feb 6, 2017
294
170
0
New Freedom
www.Spoolnmotorsports.com
Ride
2008 BMW 135i
Here is my idea for a new catch can for the 335i. I am no n00b to fabrication, nor catch cans. Ive built many catch cans in the past, and have alot of r&d into baffle designs, etc. This is my design so far, figured id show off the progress, as I am finally happy on the outcome. Will mount on the sway bar right where the bms can would. 2 -8an inlets and a 12an outlet.
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Danksies

Corporal
Nov 2, 2016
181
55
0
31
NoVA
Looks interesting to say the least. Have you considered 135i fitment as well? We have like 2 inches less room to work with up front than the 335i. Looking forward to future updates
 

N54gasm

Sergeant
Feb 6, 2017
294
170
0
New Freedom
www.Spoolnmotorsports.com
Ride
2008 BMW 135i
Sorry for the lack of update, works been hella busy. Since ADE's pcv delete fitting is out of stock and no time anytime soon to be back in stock, decided to purchase a rb turbo cap and weld on my own 8an fitting and tap the head ports. I made a mounting solution (need shorter bolts, just what I had laying around haha). Now just to wait on the flapper delete fitting to come in from ADE, and tap/plugs and I can do the head and get some more data on this can (vacuum at idle/wot, intake dry, etc).

Next on my list is power steering relocation bracket, oil/trans cooler setup and finish these damn vacuum canisters haha.

*Edit* Sorry for the horrible pics, my camera lens is shattered and refuses to focus properly lol

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dyezak

Major
May 4, 2017
1,768
1,518
0
Plano TX
Ride
335is
If you are going that far with fab work you can really clean up the install by getting rid of your bracketry and bolting directly to the brace. Drill a hole in the brace and insert a threaded insert, then bolt from the bottom up from your tabs (which you could trim considerably) into your threaded insert. I'd put a rubber bushing/isolator between the catch can and the brace though to remove stress fatigue from vibrations.
 

BeastMode335i

Lurker
Dec 28, 2016
11
2
0
If you are going that far with fab work you can really clean up the install by getting rid of your bracketry and bolting directly to the brace. Drill a hole in the brace and insert a threaded insert, then bolt from the bottom up from your tabs (which you could trim considerably) into your threaded insert. I'd put a rubber bushing/isolator between the catch can and the brace though to remove stress fatigue from vibrations.

Would that challenge the structural integrity of the brace by drilling through it..??
 

Bnks334

Lieutenant
Dec 1, 2016
511
335
0
New York
Interesting
Does a baffle that simple really catch anything? Is vacuum really even a concern? I thought the can would always be under unregulated vacuum from the intake tract and only the vacuum in the crankcase is a concern (which is regulated by a solenoid). You can have the most complex catch can design imaginable and the intact will still generate enough vacuum to pull vapor through it...

I ask because neither BMS OCC or Mishimoto's seems to really catch much oil at all on my N55. Oil blows right through the can. Then again neither can actually forces air to flow past the baffle... terrible design imo. I stuffed my can with some brass scrub pads to see if that gives the oil enough surface area to collect on as it passes through the can...
 

N54gasm

Sergeant
Feb 6, 2017
294
170
0
New Freedom
www.Spoolnmotorsports.com
Ride
2008 BMW 135i
Sorry for the delay, been swamped lately. Ive added another baffle wall in there after these pics. But to put it simply yes. The purpose of the perforated baffle is as the vapor comes in, the airflow moves through the holes and the vapor/oil catches to say the least and drops to the bottom. Also with the walls, as the airflow hits it the vapor "sticks" and drops to the bottom while the airflow continues to move out. Do this multiple times and it pulls majority of the vapor/oil out of the air. No catchcan is going to stop 100% of the oil vapor, its impossible. But to narrow it down as much as possible is the goal.

Some people go to extreme and put some steel wool in there, but I am not a fan as ive heard horror stories about it breaking apart, getting sucked in the intake, etc. Ive had a similiar can on my 900hp dsm, and a buddies tri charged dsm, as well as many other cars with GREAT results, so I see this being no different.

My old BMS can caught 90% of the oil but the intake still had some residue in it. Design is not bad, but can be improved. But for a budget can, it does great imo.
 

Bnks334

Lieutenant
Dec 1, 2016
511
335
0
New York
Sorry for the delay, been swamped lately. Ive added another baffle wall in there after these pics. But to put it simply yes. The purpose of the perforated baffle is as the vapor comes in, the airflow moves through the holes and the vapor/oil catches to say the least and drops to the bottom. Also with the walls, as the airflow hits it the vapor "sticks" and drops to the bottom while the airflow continues to move out. Do this multiple times and it pulls majority of the vapor/oil out of the air. No catchcan is going to stop 100% of the oil vapor, its impossible. But to narrow it down as much as possible is the goal.

Some people go to extreme and put some steel wool in there, but I am not a fan as ive heard horror stories about it breaking apart, getting sucked in the intake, etc. Ive had a similiar can on my 900hp dsm, and a buddies tri charged dsm, as well as many other cars with GREAT results, so I see this being no different.

My old BMS can caught 90% of the oil but the intake still had some residue in it. Design is not bad, but can be improved. But for a budget can, it does great imo.

Bms can caught literally nothing for me. The mishimoto only caught some vapor. Not much oil at all:

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I actually took the scrub pad out. I still wasn't catching much. I have since started running the mishimoto can in reverse. The results speak for themselves:

Seems like when running in reverse the brass filter on the inlet allows vapor to form droplets. The droplets then fall down into the can and collect on the diffuser plate.

Maybe airflow is slower? Not sure why but the only time I collect any oil is in reverse lol

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