Killjoy32

Yes Pics please

Jmc007

http://www.******************/forums/...7&page=2&pp=10

See page #2, post #13.

Jmc007

I think I found the easiest way to do it (Maybe you will say that it seems to be the same mod they do on the following site http://www.saturnionredline.com/boostmod.htm but it will not produce the same effect !!!) The way they've done it on this site caused the bypass valve to be always closed; the actuator's lower nipple is closed, so the "before blower vaccum" is not able to make the actuator (by-pass valve) opened. It results in a by-pass valve that is always closed and that is not good for fuel economy and efficiency.

So here it is: Unplug the end of the hose that is located on the lower nipple of the bypass actuator (this is located on the side of the supercharger), and plug the end of the hose with a screw (Don't plug the nipple !!). Period. (Yes this is the hose between the selenoid and the by-pass valve. IMPORTANT you must disconnect it on the blower side, not on the selenoid side. Then plug the hose, not the valve's nipple ! Leave the valve's bottom nipple to the air.)

The following result is that you will be running no boost at idle and the same low boost when cruising (all like stock), but you will be sure that in any ways at WOT you will get the max boost from your supercharger, if the allen screw on the by-pass actuator is set in a way that the valve is 100% closed).

What do you think ?

99_civic_si

yeah, that is a great way to do it in that website and will not cause the bypass to be closed at all times....that probably also will not throw a code. However I'd just like I said earlier, cap the nipple right at the manifold that goes back to the solenoid. remove both hoses that go to the solenoid alltogether, and leave the lower hose off of the bypass valve. I say leave the lower one off the bypass because you don't want any unwanted vac/suction due to the fact when the solenoid is not "open" or letting air pass, it slows the reaction time when the upper nipple recieves vac. I know this because I originally plugged the lower nipple to the bypass and when I applied vac to the upper nipple to open the bypass, it operated very slowly when the bottom nipple was plugged. So with that known, I highly reccomend just leaving the lower nipple exposed to open air.

edit: what I did, is exactly what you just described, only I removed that hose all together and capped the nipple on the solenoid and zip tied it so boost won't blow it off. But yes, like you said, don't cap that lower bypass nipple as it slows the operation of it.

Jmc007

Exactly, but the way they have done it on the web site, it makes the lower nipple closed, because the selenoid is a normally closed valve and is also normally closed in most of the conditions, exept for the conditions Maven stated. So it avoids the by-pass actuator to lift properly. So it cause the by-pass to be closed mostly all the time.

Jmc007

I've done it this morning; it runs well.

But for those (like me) who are already running full boost (12 or 12,5 PSI) at WOT, it will not profuce more boost.

But it will ensure that the PCM couldn't vent the boost under the specified abusing conditions.

Have a nice day !

Jmc007

Just to make sure everybody undesrtand it well:

It SEEMS to be like the boost by-pass mod some previously did, but it is not the same results !!! It is a waaaaaaay safier than have the by-pass valve always closed.

The way i've done it (99_civic_si also), I DON'T By-pass any mechanism but the selenoid itself AND the by-pass valve CAN close AND open just like stock.

So I don't make boost earlier than stock, I don't make higher boost, at idle and cruise it doesn't make high boost as stock, BUT when in some abusing condition then the PCM cannot tells the selenoid to vent extra boost, because the selenoid is no more effective.

I hope it is clear, unfortunately I have no picture yet.

Jmc007

Go to this website ...

http://www.tomhenryracing.com/technical/default.htm

... then scroll down, look at the picture on the very bottom. The left red arrow is pointing the blower's internal by-pass valve (butterfly) and the right red arrow is pointing the by-pass actuator (black cylindrical box).

On our cars (Redline or SS), the actuator is pointing upwards, so find the upper hose (the hose between this actuator and the selenoid) and unplug it on the side of the actuator. Then plug the end of the hose with a screw, and leave the actuator's nipple opened to the air.

It will permits the actuator to open and close like stock, but the selenoid won't be able to bleed the boost ...

Jmc007

I found that the little Allen screw on the by-pass actuator is probably not set equal for one car to another. The best is to unscrew it since you feel that the by-pass butterfly (inside the supercharger) is properly closed (sitten), then you screw a little bit the screw to sit with the swivelling arm.

99_civic_si

jmc007 is right on the money and definately understands how the system works. Yes, it allows for perfect part throttle operation this way. Also, you mentioned the adjustment screw on the bypass. I did actually play w/that to see if maybe it wasn't lined up to a perfect 90 degree to completely block the bypass, but it was. Turning it either way, I ended up losing boost because the butterfly in the bypass wasn't completely shut. I did wonder if this car had more than 12.5 psi in it through some **** like this but it didn't.

Jmc007

99_civic_si thanks for the compliment, but your posts helped me a lot to understand better these components.

When the engine is off, the by-pass valve is 100% closed (normally closed).
When the engine is turn on and idling, the by-pass valve turns 100% opened by the intake vacuum.

I have done a test: With the hood opened, i ask my friend to hit the gas pedal (in neutral gear of course), and I saw immediatly the valve who rapidly close 100% (sitten completly to the allen screw).

And as written on the service manual of the car ...

"The bypass valve starts to close when the vacuum measures 250 mm Hg (10 in Hg) and is fully closed at 90 mm Hg (3.5 in Hg)." It's about respectivly minus 5 PSI (vacuum) and 1 PSI vaccum.

And the following arrives under very rare or abusing conditions ...

"When reduced boost pressure is desired, the PCM commands the boost control solenoid to operate at a 0 percent duty cycle. This opens the solenoid valve and allows boost pressure to enter the bypass valve actuator at the lower side to counteract the spring tension, opening the bypass valve and recirculating excess boost pressure back into the supercharger inlet."


So the best is to keep all hoses stock, but there is 2 ajustements to fine tune it:

The First one is the little allen screw, nearly unscrewed at the max, and here is the second one:

There is 2 nuts holding the by-pass actuator, you can unscrew it and push down the actuator the most possible, the tighten them. Make sure that you not push down too much, because it will open the butterfly (you'll see it when ajusting). This way you will not achieve higher maximum boost, but if you successfully push down the actuator a little bit, his inside spring will be compress with a little higher pretension, which will cause the boost to come a little bit sooner. For me it works, and i saw on Pontiac Grand Prix forums that most have done it.

Have a nice day !

Larry

I have a supercharged Matrix. I've contacted Magnuson about the bypass valve and was told if it's not allowed to open and close the SC itself and the engine will overheat over time. Be careful with the bypass valve and don't do any mod that prevents the bypass valve from opening and closing. You also hurt your mileage if the bypass valve is left closed all the time.

http://www.magnusonproducts.com/bypass.htm

99_civic_si

Larry, the way we both explained it, it is perfectly safe and will not prevent it from opening and closing. It just causes it to open and close when it really should without letting GMs solenoid take over and rob you of boost at times where you may want the boost. AKA, GM is making the car a bit slower but more idiot proof. Kinda goes with the old saying: Fast Cheap Reliable, Pick any two you want. In this case GM took away some of the fast, and it added reliability. Which loops back to the whole domestic vs import debate, and honda kids will scream their car is reliable blah blah blah........I don't even consider 12 second car fast.....The best I have on paper is a 12.6 (not bad for an auto-x car eh ) and I gotta say, yeah my car is reliable......only if I'm not beating on it all the time. But as soon as I start using all of the little bit of power I got, **** starts breaking. In drag racing, when ur cutting 1.6-1.8 60's with an economy car, **** is gunna break over time. Moral of the story I think, you bought a FWD car with a LSD, auto-x the thing instead.

Holy **** I just reread that post, and I was very tempted to delete it. I started off good and just went off on a tangent out of ******* no where. Ahh well.

Larry

I agree 99 civic. My post was advice directed toward those that may or are bypassing the bypass valve in a way that it is closed all the time.

dr.mike

Hi all.

Does anyone know what frequency that bypass valve is supposed to operate at ?
I was thinking of making a quick PWM boost controller unit.

Thanks.