09-16-2021, 09:01 PM | #1 |
Registered
0
Rep 3
Posts |
F30 2015 335 xi Vacuum cut out
Hello all, I need help.. I got this thing https://www.ecstuning.com/b-ecs-part...20923ecs01~dk/
Cut out vacuum actuated, I installed everything but I have a problem.. I can't get enough vacuum from the map, I got a boost tap on the map but it's not enough. Any one got a idea how I can do it.. Yes everything works fine we tried to open it with a vacuum pump. Thanks all |
09-16-2021, 11:18 PM | #2 |
Major General
4358
Rep 7,591
Posts |
How much vacuum does it need?
You are only going to have positive pressure post-turbo when under load and you aren't really going to ever have vacuum pre-turbo unelss you have a massive intake restriction... so the MAP isnt going to be a vacuum source when you need it. |
Appreciate
0
|
09-17-2021, 05:03 PM | #4 |
Major General
4358
Rep 7,591
Posts |
IIRC the highest vacuum i have ever seen pulled on the MAP is -0.7psi, whereas your cutout requires ~4 psi, and that's only at low/no throttle (i.e., idle or decel). If you want the cutout to open under WOT/boost, you are never going to get it to work by connecting post TB which you necessarily have positive pressure and not vacuum at the MAP under those conditions. A vacuum-actuated cutout is just not correct for this application with where you are trying to tap into
|
Appreciate
0
|
09-18-2021, 07:27 AM | #6 |
BMW CCA 69606
86
Rep 225
Posts |
N55's have an engine driven pump that provides vacuum for the brake booster and evacuates the crankcase. Be sure your connection is reliable so you don't loose your brakes unexpectedly.
|
Appreciate
0
|
09-18-2021, 01:33 PM | #7 |
Major General
4358
Rep 7,591
Posts |
Yeah, but is this going to provide vacuum when he wants it and no vacuum when he doesnt want it? I am not entirely sure how this varies with engine load/rpm/etc
|
Appreciate
0
|
09-18-2021, 03:26 PM | #8 | |
BMW CCA 69606
86
Rep 225
Posts |
Quote:
EDIT: Scroll down the link to item 3. It's another $50 or$100. Last edited by pshovest; 09-18-2021 at 03:34 PM.. |
|
Appreciate
0
|
09-20-2021, 12:21 AM | #9 |
Major General
4358
Rep 7,591
Posts |
Gotcha, it just sounded like OP was trying to get this to open under vacuum at WOT, which is the opposite of what tapping into the MAP would do.
|
Appreciate
0
|
Post Reply |
Bookmarks |
|
|