dkennedy1989
Member
If you had the stiffer spring in would it do any kind of damage? I have the forge atmospheric BOV.
Sent from my iPhone using Tapatalk
Bypassing the the bypass valve solenoid.
- Thread starter MPFab
- Start date
If you had the stiffer spring in would it do any kind of damage? I have the forge atmospheric BOV.
Sent from my iPhone using Tapatalk
His method and my method are the same with one caveat. My method uses the factory BPV line and his runs a new, separate line. Both methods hook up to the same ports and cap/plug the same ports.
There are two blk/grn hoses connected to the solenoid. The one you want to remove is on the passenger side of the intake manifold. It is about 2.5" long and goes from the intake manifold to the solenoid(This is the hose people are having a tough time removing). It is near the alternator. This is the hose described in both methods.
DO NOT touch the blk/grn hose that runs from the solenoid over to the vac. container under the center of the manifold. This is NOT the hose described in my method.
Please go back over the diagrams before attempting this. The car will not run correctly if the correct hoses aren't swapped.
Good luck!!
Thanks for the clarification! I just finished doing it. For the life of me, I couldn't find a 5/32" hose coupler at any of the auto parts stores I visited. I ended up getting a 5/32" tee connector and capping the third outlet. I cut the blk/grn cable at the solenoid and used the tee connector to mate the BPV cable to the manifold cable. I used a blade to cut off the remaining bit of hose on the solenoid fitting. I capped off both ports on the solenoid and put everything back together. I started the car and drove it around to make sure that there were no problems but didn't do a thorough road test. My only possible concern is that the mated cable is rubbing up against the plastic intake manifold. Is this something that I should be concerned about or is it ok if it makes contact with the manifold?
Vacuum to the BOV is not effected by doing this mod. It remains the same as it always was. You no longer have a solenoid that diverts boost signal so that the BOV is slightly open almost all the time. If the BOV is open slightly, you will never hear the "flutter dump" you speak of. Now that the BOV gets full signal, it actually stays seated and the stiff spring is not needed, and will only cause problems.
The vacuum chamber that was also hooked to the solenoid doesn't increase vacuum, it's just a storage tank that allows the ECM to open the BOV and hold it open so that the car can no longer build boost when it deems it necessary.
Glad to hear you got a handle on it swapping springs.
Preloader
The M32 Martyr
Vacuum to the BOV is not effected by doing this mod. It remains the same as it always was. You no longer have a solenoid that diverts boost signal so that the BOV is slightly open almost all the time. If the BOV is open slightly, you will never hear the "flutter dump" you speak of. Now that the BOV gets full signal, it actually stays seated and the stiff spring is not needed, and will only cause problems.
The vacuum chamber that was also hooked to the solenoid doesn't increase vacuum, it's just a storage tank that allows the ECM to open the BOV and hold it open so that the car can no longer build boost when it deems it necessary.
Glad to hear you got a handle on it swapping springs.
^^^This^^^
And that's what makes this mod so effective IMO. The boost is more responsive when it's not constantly sneaking out the backdoor.
Patgt500
New member
The vacuum chamber that was also hooked to the solenoid doesn't increase vacuum, it's just a storage tank that allows the ECM to open the BOV and hold it open so that the car can no longer build boost when it deems it necessary.
Glad to hear you got a handle on it swapping springs.
Sorry I wasn't clear, I wasn't saying that the canister raised vacuum "pressure"(-mbar). I was saying that it was used to increase volume, just like a cap on a car sound system doesn't raise line voltage to the amp, it just makes sure there aren't any spikes or lows. By lowering the volume at the same -mbar, the bov initially opens as it should, but since there is less volume of vacuum, it closes momentarily until enough is built back up to finish venting the additional pressure(boost). Also a rough definition of flutterdump, which also momentarily leaves unvented pressure in the intake tube pre TB. And yes,the ECM did use the solenoid and canister for it's own dastardly deeds, but since the canister isn't actually a true vacuum reservoir as it has the manifold opening(per Preloader's earlier post), it wouldnt be able to hold vacuum for any real length of time, just when engine conditions permitted.
THE MAIN thing is thanks MPFab for this mod, it changes the Sonic into an even more fun car to drive, all while being pretty much free. Can't say that about alot of others.
Last edited:
What?
Pretty sure he showed that it has a one way valve to the vacuum chamber which basically makes it a vacuum storage tank.
Preloader
The M32 Martyr
Sounds like a disagreement about agreeing.
I like the vacuum capacitor analogy.
The vac tank pretty much has enough volume to give the ECU a supply of vac signal during long boost runs.
Anytime the IM goes into vacuum, it "charges" the vac tank back up via the one-way orifice connecting the two.
It's actually quite impressive.... Retarded..... But impressive.
I like the vacuum capacitor analogy.
The vac tank pretty much has enough volume to give the ECU a supply of vac signal during long boost runs.
Anytime the IM goes into vacuum, it "charges" the vac tank back up via the one-way orifice connecting the two.
It's actually quite impressive.... Retarded..... But impressive.
Just on a side note. I think this mod had an effect on my traction control system. In a positive way. Before, the second I had slippage , my car would dump boost and limp out of the situation. Not it seems to hold it a bit longer and keep trying to move forward. Or maybe I just did something different. The roads were slick and I will do more "testing" tonight when I get off
The other thing that I have noticed with this mod is that my vacuum while cruising at the same speeds on the same roads under the same conditions has drop 5-10inHg. This is likely how myself and Preloader have noticed better fuel economy out of this mod.
That and we aren't creating excess boost and just dumping it out and back in to be compressed again.
That and we aren't creating excess boost and just dumping it out and back in to be compressed again.
Just to be clear, it triggered a light?
Tune? Did you unplug the electrical connector?
Stew
Sedans Rule!
I did this mod yesterday and did about 120 miles driving around today, I've got to say I can't really tell much difference. It feels like it may be a little snappier when getting on it, like boost ramping up a little faster, but not enough to discern a definite difference.
You guy's with boost gauges may be able to tell better, needle sweep is an awesome thing, it's not so obvious with my scangauge because the readings only update every half second or so.
You guy's with boost gauges may be able to tell better, needle sweep is an awesome thing, it's not so obvious with my scangauge because the readings only update every half second or so.
Looking at your mod list I don't see a tune listed. Your results may differ from others because at stock boost levels, the turbo isn't really being pushed. The BPV valve leaking a bit may not be noticeable. Hell, at stock boost levels the turbo isn't even that noticeable!
dvn
New member
True dat!Hell, at stock boost levels the turbo isn't even that noticeable!
Stew
Sedans Rule!
Looking at your mod list I don't see a tune listed. Your results may differ from others because at stock boost levels, the turbo isn't really being pushed. The BPV valve leaking a bit may not be noticeable. Hell, at stock boost levels the turbo isn't even that noticeable!
True dat!
Lol, yep, no tune for me yet, waiting until I get a little closer to the warranty expiring. I'm sure you guys are right, the guys and gals with tunes would notice this much more. Dang it, I'm never gonna last until the warranty runs out! Must resist urge to tune... have to remain strong... willpower is getting weaker...