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How To: BOV on natural vacuum

87K views 112 replies 45 participants last post by  SSgtjrobertson 
#1 · (Edited)
Hi everyone,

Wanted to put together a proper "How to" for moving the blow off valve over to natural vacuum and removing it from the stock solenoid. Hopefully this helps anyone that is looking to make their Turbosmart or Boomba BOV blow off properly! This might requiring adjusting your BOV after the install to adjust it to your desired BOV preference.

Shout out to a fellow ST member for letting me use his car to complete this write up!

Parts required:
1 - 3/16" Vacuum cap (NAPA Auto is where I picked up a 5 pack for $3)
1 - 2 feet of fuel line 3/16" ID
1 - clamp
1 - Sound symposer delete kit with vacuum port or CPE
( cp-e™ Ford EcoBoost 1.6L & 2.0L Turbo MAPtap™ - cp-e™
cp-e™ BlockD™ Ford Focus ST Sound Symposer Delete - cp-e™
COBB Support )

Tool:
pair of pliers and cutters
8mm wrench to remove the sound symposer delete
maybe a 7/16" wrench to put on the barb

(Picture shows a barb we has that we picked up from ACE hardware because he didn't have the barb that came with his COBB SSD, for reference if you need one it is a 1/8NPT with a 3/16" barb part number is in the picture 4504130)

Auto part


Next picture is just reference to show what it should all look like stock:

Auto part Engine Vehicle Fuel line Car


1) Unplug vacuum line going to the BOV from the solenoid

Vehicle Auto part Engine Car Subcompact car


2) Using a vac cap, cap off the solenoid port that the line was removed from

Auto part Vehicle Engine Car Family car


3) Remove factory soft vacuum line from the hard line and replace it with the 2 feet of soft line and route to MAPTAP or sound delete vacuum source

Engine Auto part Vehicle Fuel line Car


4) last one is just to show the location of the sound delete and how the line routes to it's location.

Engine Auto part Vehicle Fuel line Car


Thanks
Nick
 
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#2 ·
6 likes and 0 comments... :in love: guessing it is so good of a review no one has feedback other than a like? :sorry:

Hope this reaches many people and helps many more! this can be my Christmas gift to the community :crazy:
 
#3 ·
Very niiiice (in Borat voice)
 
#10 ·
I have had to drill and tap mine as well. My ACE Hardware had both drill and tap.

NAPA is where I got everything else. O'Reilly only had vac caps in a kit and I just wanted a single cap. for the picture I have a 5 pack but that is because I have been doing cars in my local club left and right.
 
#18 ·
the quick and easy is it supplies true/natural vacuum to the BOV opposed to have a controlled vacuum via a solenoid and the vacuum pump.

It will keep the BOV from blowing off when it really didn't need to blow off. It will hold boost based on vacuum and not based on what the computer telling the solenoid to do.

Maybe someone has better way of explaining it and even more in depth knowledge.

If you really like a LOUD BOV that goes off all of the time for no real reason... then this is NOT the mod for you.
 
#20 ·
Which BOV are you referring to? TIAL, HKS, Boomba, TurboSmart?

I did put in a blurb about BOV will require adjusting. Though I didn't feel the need to change out the spring. but good mention.

If you have springs for each application for this mod that would be helpful and I can add that.
 
#45 ·
Hey Unfocused thanks for all your input, its helped me alot. I'll be ordering a BOV this weekend and doing this install soon. I'm new to this though, are you saying that turbosmart is designed to run off factory vacuum? Basically, I'm asking for recommendations for going with turbosmart or TiAL on this set up. Thank you

Sent from my SM-G965U using Tapatalk
 
#28 ·
I'm not sure why you would do this mod using the Mountune BPV, I have the same one also (BPV) and aside from nickbalwin86's observation, I don't see this mod benefiting since its not a true vent to atmosphere BOV like these other guys are running? I have the Mountune Symposer delete and I just used the supplied screw plug to seal it closed. When I want to hear the woosh I just pop on the RS lid and run the open end filter with it.
 
#25 ·
I have been running mine this way for a few months. I do not feel any difference in my turbo response and watching the AP I get movement from low vacuum to increasing into boost anytime I touch the go pedal. Not like the valve is open still. Who knows though. I just like it only venting when it is supposed to.
 
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#35 ·
Noob question: 3/16" line and caps, is this inside or outside size? Sourcing parts, but they come in a lot of sizes here
 
#39 ·
Thanks so much for this write up. I installed a boomba BOV and was disappointed in the way it hissed with minimal throttle all the time. I switched it today with a symposer delete kit I had for a while and what a difference. It has that blow off under heavy boost release like it should and no annoying constant hiss under normal driving. I haven't found any negatives in making this change. Thanks for taking the time to post this!
 
#43 ·
New to the idea of BOV's, but how does this help? I've heard from car groups that it makes the BOV go off less. Is that true? I recently ordered a 50/50 TS BOV, as much as I would like the sound of the BOV, I'm sure it gets annoying after a while. I also prefer the sound of an open(no box) intake over a BOV. Would I be able to hear them both? I don't intend on going bigger turbo or tune anytime soon. Also plan on keeping my warranty so I'll probably be taking it off every time I go for a service( I know that sounds dumb, but I'd rather play it safe). I appreciate if anyone reads my dumb questions and responds. Have a great night!
 
#44 ·
yeah the natural vac "makes" it go off less or more accurately makes it go off more accurately and not just when a solenoid and a vac pump tells it to go off, like every time you barely give it gas and let off. It now will only go off when vacuum from your intake manifold triggers it to "blow off".

Turbosmart recommends moving the BOV to natural vac, tho few do it, I think more have been changing to it. I know I have moved nearly everyone in our local club to this setup

the "mod" is super easy and if you needed to change it back before a service it is literally pulling the extra vac line and plugging it back into the old location.
 
#53 ·
So glad I found this!!! I just got a 2018 ST3 and installed the turbosmart 50/50 and I knew something was wrong when even on the hardest setting it will blow off ALL THE TIME. I ordered the cap and tubing from amazon and the accelatec symposer delete with gauge port from CJ's. Cant wait to install it this week so it works properly.
 
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