Boost Operated Blow Off Valve - Boomba Racing

[TheLion]

The design of this blow off valve itself is very similar to something like our Focus ST one. The biggest difference would be the Mustang specific bolt pattern, depth, and spring pressure.

Getting back to the questions above, there is debate on the control mechanism of the BOV. It's well understood that you need to use Boost and Vacuum to physically operate the valve properly no matter who makes it to prevent fluttering and leak.

The debate is in the control mechanism. A pneumatic pressure switch, which is the traditional method, or the ECU controlled manifold. While both are powered by pneumatic, one method is fixed, so you set it and forget it, it works the same every time. The other method, ECU control method as with the factory and Boomba architectures, allow versatility, the ECU can change the parameters under which it operates the valve as opposed to being fixed.

What is the advantage of an ECU controlled valve as opposed to a traditionally fixed valve?

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[Boomba Racing]

For anyone asking, this BOV can be run full mechanically off of a vacuum line. However we're not sure why you'd want to when our kit comes with everything you need, including a solenoid which will make the valve not flutter.

 

[jbailer]

For anyone asking, this BOV can be run full mechanically off of a vacuum line. However we're not sure why you'd want to when our kit comes with everything you need, including a solenoid which will make the valve not flutter.

That's great news! In my opinion, it really makes this an ideal BOV. The way I see it, you can install this with no other mods or tune and the same BOV would carry you through whatever growth you take including big turbo later.

Am I correct in saying, "you can install this with no other mods or tune"? It seems like it would allow vacuum and ecu control of the BOV and the boost pressure helps hold the valve closed. Is that correct?

 

[TheLion]

For anyone asking, this BOV can be run full mechanically off of a vacuum line. However we're not sure why you'd want to when our kit comes with everything you need, including a solenoid which will make the valve not flutter.

Then perhaps that's one of the primary reasons Ford went to ECU controlled operation as opposed to a fixed pressure switch. Pressure spikes usually have harmonics associated with them, a pressure switch may not be able to adequately filter them out, hence the fluttering.

 

[Boomba Racing]

That's great news! In my opinion, it really makes this an ideal BOV. The way I see it, you can install this with no other mods or tune and the same BOV would carry you through whatever growth you take including big turbo later.

Am I correct in saying, "you can install this with no other mods or tune"? It seems like it would allow vacuum and ecu control of the BOV and the boost pressure helps hold the valve closed. Is that correct?

This BOV can be installed on a vehicle that is 100% stock with no special tune required. The flexibility aspect which is pretty sweet is that you can also install this piece on a highly modified vehicle with an aftermarket tune, as well!

 

[Boomba Racing]

Words came up at the meeting today about a fully recirc piece!

 

[TheLion]

Words came up at the meeting today about a fully recirc piece!

Why would you make a fully recirculating valve other than sound supression?

 

[whokilledkaji]

This BOV can be installed on a vehicle that is 100% stock with no special tune required. The flexibility aspect which is pretty sweet is that you can also install this piece on a highly modified vehicle with an aftermarket tune, as well!

How about euro spec? Good to go?

 

[Juben]

Back when I was in my twenties, I'd have chosen a VTA BOV every time, but these days, I'd take a nice upgraded recirculating model if one was available. I made the same choice on my Fusion too. Boomba produces some awesome quality products, but I went with the Mountune valve because it was stealthy and quiet.

I'm interested in seeing any developments on a recirculating valve. Honestly, I don't know that there'd be a large market for it because most people, especially those new to turbos, like the whooshy sounds, but there's probably a few of us around that'd seriously consider an upgraded recirculating valve.

I've got mine recirculating right now and it helps people to believe it's a V6.

 

[TheLion]

How about euro spec? Good to go?

Domestic ebs are MAP tuned which makes them immune to the issues associated with venting to atmosphere. Ero ebs are MAF tuned, so a blow off valve will throw off your fuel trim. You would needd a diverter valve instead of a bov valve.

Btw i just installed the boomba two days ago. Works great, i loke the more subdued sound vs a whistly one as some bovs produce, but most noticeably is that low rpm operation is both smoother and more sponsponsive when lightly accelerating. In the 1500 to 2000 rpm range is particulalry improved.

 

[BoostedRubyRed]

If and when they came out with a recirculating version, then looks like it would be a welcome upgrade to the factory plastic valve.

 

[TheLion]

If and when they came out with a recirculating version, then looks like it would be a welcome upgrade to the factory plastic valve.

Given the power and torque curve difference from the factory diverter valve, I would agree with this 100%. You shouldn't gain power by upgrade a BOV / diverted valve...but due to cost cutting measure in this case, it leaks like a siv. Same with an inter cooler, I would not expect high end cars like Ferrari, McLauren or even Mercades to experience power gains by upgrading support components on an other wise stock engine.

Then again, I suppose the EB stang is a hidden treasure chest of go fast for cheap that is really un-matched by anything else on the market that I'm aware of, if your willing to get your hands dirty and spend $1k or $2k...

 

[jbailer]

A good dyno operator (or probably not even a good one) can do 2 runs and show a small improvement on the second run without changing anything. I'm not saying this was done, just that there's no expected consistency. Rather than the dyno showing HP and TQ, I think it would be great to show the pedal position (100%) and the measured boost over RPM. That way it would show the leak off the stock cheap plastic valve.

 

[TEXAS HEAT]

A good dyno operator (or probably not even a good one) can do 2 runs and show a small improvement on the second run without changing anything. I'm not saying this was done, just that there's no expected consistency. Rather than the dyno showing HP and TQ, I think it would be great to show the pedal position (100%) and the measured boost over RPM. That way it would show the leak off the stock cheap plastic valve.

This was actually my original request when Boomba made this thread. I wanted to see the associated boost curve for both of the dyno runs they were comparing so that we could indeed see the fluctuations represented in graphical format. Not that I'm saying their product doesn't work, the scientist in me would just like to see it.

 

[TheLion]

I've been running the BOV for about 4 days now. Got it completed Saturday evening along with the Levels FMIC. But i've run into an anomaly which I am trying to sort out the cause of.

Under light load conditions, while cruising at a relatively constant speed, some times the BOV will remain open continuously. It's loud enough that I can hear it easily with the windows rolled down. It will remain open even as I give it more throttle for a short period of time, which becomes very obvious as there's little response form the engine and the vented air becomes even more audible. I cannot reproduce this occurrence on demand, but the last occurrence (yesterday) I noticed there was no boost or vacuum (bouncing around the 0 mark) while the issue occurred, which coincides with the fact that the valve is open, hence why the pressure gauge is reporting atmosphere instead of vacuum or boost.

Some possible causes:

1. Solenoid valve in the control manifold is sticking

2. BOV plunger is sticking

3. PCM software has a bug, possibly too much hysteresis, causing the valve to open, but the lower trip point to close it set too low, thus we're operating in the dead band of the hysteresis bounds and hence the valve remains open so long as the conditions don't vary significantly from the initial occurrence which caused it to open.

4. PCM software is functioning as intended and this is a design oversight on the part of Boomba. It is possible that the PCM may be holding the valve open by intent in these conditions to bypass the turbo while under very light load for fuel economy purposes, if the turbo isn't spooling enough to produce boost, it serves only as a restriction on an engine operating in the NA region (pressure at the throttle body is a vacuum, not under pressure when the turbo being driven fast enough to generate boost). The bypass tube between the compressor inlet and outlet is large enough to support adequate flow at low loads.

At this point in time I have not had much time to diagnose the cause of the issue, but have only become aware of it. Cause number 4 seems to be the least likely, but I have no proof of the factory PCM software's architecture to rule it out completely. I also have less visibility of the factory DV operation as it's not audible and I'm now aware of any PID's that monitor the BOV state. It may be a blind output, meaning the PCM drives the valve but has no visibility of it's actual state and operates by assumption that the valve is actually in the position commanded. The PCM software would certainly be aware of when it has commanded the valve to be in a particular position, but the valve may not actually be in that position.

The most likely would be causes 1 or 2, which I may be able to resolve by having Boomba replace the components or at the very least assist in diagnosing the issue. I would like to first test the vacuum operation of the valve by using a negative pressure sources to manually drive the plunger. I can use a manual air pump to test the pressure required to force it to return if it does not return under atmospheric (which it should due to the return spring). The valve should remain closed under atmospheric and under boost as the holding strength is still the spring rate (the turbo outlet pressure has a net 0 effect on the BOV plunger as the plunger is held shut by the same pressure, thus the mechanical spring in all instance is the holding closed pressure).

The Solenoid might be a bit more tricky, but I'm sure I can come up with an appropriate supply voltage to operate the mac valve. BTW, anybody know the operating voltage of the MAC solenoid? It would most likely be 5V or 12V, I could test 5V first, if no operation then 12 would be appropriate.

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