Bypassing the the bypass valve solenoid.

[sx sonic]

Any word in increase off
Or decrease in mpg from this mod?

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Negligible to nonexistent change in fuel economy.

 

[Sonic_Boost]

Sooo this mod essentially came undone on my way to work this morning. I arrived and opened the hood to see the BOV line has blown itself off of the intake manifold.

The symptoms were when i was accelerating through boost and hearing my intake "pssh" as if i let off the throttle but i didnt. So i just made sure not to hit boost the rest of the ride. (wasnt far)

I'm not sure if the solenoid where the bov line was is still capped though. I couldnt seem to find it an the engine was hot so i will look later.

Any key things to direct me exactlly the spot to look for said solenoid cap spot?


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[dvn]

Any key things to direct me exactlly the spot to look for said solenoid cap spot?


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Don't you remember where you put it when you did the mod?

 

[cndctrdj]

One of my vac hoses came off after this mod. It was because I had not put it on correctly. It is fixed now.

 

[Sonic_Boost]

I do, but i just cant seem to locate it in the dark abbise of behind the engine/under the intake manifold haha


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[rsSteve]

I do, but i just cant seem to locate it in the dark abbise of behind the engine/under the intake manifold haha


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This is a picture of where you need to place the vacuum cap on the intake manifold

 

[Sonic_Boost]

This is a picture of where you need to place the vacuum cap on the intake manifold

Youre the best, thank you!


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[AJH]

Just a thought

So I did the bypass, bypass. Best $3.45 I ever spent on a car. I pulled the two lines off the solenoid, connected them with a 5/32 connector (with clamps) and put two caps on the solonoid. My Sonic pulls strong and I am happy.

But I had to wonder "Why did the GM engineers put the valve on in the first place?" Was it just to soften the power delivery? No one has blown their engine or killed their turbo. I couldn't shake the feeling that there might be more to the story. GM Engineers are not stupid, and adding parts costs money.

I think I know one function of the bypass. I was driving up Rt. 95 on the way to visit the folks last week. It was hot so I had the a/c on and the cruise set to a leisurely 70 mph up a long incline when I felt a VERY mild surge every time the AC compressor kicked in. With the radio off I thought could hear a little turbo spool each time it did it. Let me be clear, you have to really look for this to notice it, but I could reproduce the results 100% of the time. It only lasts a moment, and it isn't a big deal... BUT I my theorie is the valve helps smooth out things like this that GM does not want the "average driver" to experience.

My Sonic is stock except for the bypass/bypass

What do you think?

 

[sbelljr]

Driving in high gear up inclines will typically spool the turbo a bit. It is controlled by the wastegate to prevent too much boost.

The bypass valve controller is there to allow ECU control of the bypass valve, simple as that. In typical use, it works with the electronic throttle to release boost sooner upon lifting your foot, whereas now it will not release boost until there is vacuum in the intake manifold. When I did this mod, that extra delay was causing minor compressor surge (back flow due to high pressure but no air flow due to the throttle being closed) at part throttle lift offs because the vacuum didn't set in quickly enough.

Lift accelerator - > ecu drops boost - > ecu moves throttle closed
Vs
Lift accelerator - > ecu closes throttle - > charge pipe pressure increase/vacuum building in intake manifold - > vacuum sufficient to open bypass valve

The other use for ECU control would be for traction/stability controls and limp mode.

 

[94383Z71]

It was said earlier that much of what we're bypassing are features to "produce consistent, reliable power delivery" and "driver comfort".

Like you said, that change was minimal, but you can bet people would go to the dealer over it, were they not of similar mindset to us. Same as with the Trifecta tune giving you more power when conditions are favorable, but falling off when they're not. Consumers like the same car every time they get in, even if it means less peak power.

Edit: Very good technical explanation above.

 

[2014 Blue RS]

These last few are a bit confusing. I'm hoping once i attempt this and i'm looking at it i will understand.

My first mod. I think I did it right. Unplug the two hoses indicated and join them together with a connector. Then put a rubber cap on the place I pulled each hose off of. For what it's worth, here's a pic of the tools I used that made this very easy. Sliding the pic between the hose where it's connected and then pushed down with paint stir stick (low tech I know). Popped right off and allowed me to put down force where I needed it without damaging the line.

Trying to pay it forward by sharing a helpful tip.

 

[2014 Blue RS]

Check engine light came on yesterday. Should I be worried? Did I do it right?
Here's what I connected:
This hose pulled off like it shows and put a plug on the intake.

 

[2014 Blue RS]

Then connected it to this hose and plugged where I pulled it off as indicated in the pic. Sorry for the multi post. Didn't know how to insert pics and then comment in between them.

Thanks for any feedback

 

[Dubbs_RS]

You should not have but a plug on the intake. The plug goes on the hose you pulled off the intake (that black and green one in your pics) and then a plug goes on the bypass solenoid (which should be where that little, angled section of black hose came from in your second picture). You need a new short piece of vacuum hose to come off of the intake manifold and you splice that to the piece that came off of the bypass solenoid.

It sounds to me like you said that you plugged the intake manifold itself? That would explain your check engine light because your engine is expecting the recycled air from the bpv, but it isn't getting it because there's now no hose connecting them.

 

[2014 Blue RS]

Ahhh. Ok got it. Sounds like I should've pulled the hose from the other end and plugged that side. But either way, I get it now. Thank you for explaining that.:banana:

 

[Dubbs_RS]

If you pull the hose from the other side make sure you plug that end of the bypass solenoid as well. I personally think it would be easier to cut a new piece of hose to attach to the intake manifold and plug the black and green one so you don't have to blindly fumble around looking for the other end of the bypass solenoid.

No matter how you slice it, you should have two holes to plug.

 

[2014 Blue RS]

Dubbs RS, thanks man. Popped the green striped line from the other side. Piece a cake using those pics to break the seal. That pic with the hose pulled off just made me think that was the one to connect to solenoid vacuum line.

Anyway, thanks again. I'll get that code cleared and start dreaming of the next upgrade. Trifecta tune or exhaust I think.

 

[Mikeygoolsbay]

So how bad is it if I broke the fitting off the solenoid... It's the one that goes to the plastic line. Can I just use some RTV to seal it up as Lin. As I make sure it's fully cured before I start it up

 

[sbelljr]

As long as you've got a vacuum line going from the intake manifold to the bypass valve, you should be fine sealing the solenoid permanently (especially since it is now broken and you can't go back to using it anyway).

 

[Mikeygoolsbay]

Could I just completely remove the solenoid and plug the other line going to it?