GZE intake

[mic*]

Can someone please confirm that what i have highlighted below (1G-GZE) is some sort of solenoid bypass that allows air to be sucked through to the cylinders without having to be drawn through the SC lobes when the SC is NOT engaged.

If so how do i test it? I am getting about 14L/100km out of average driving and the way the car feels i suspect that its pulling air through the SC.

In the opinion of others, could the engine turn the lobes slowly (by vacuum) to pull air through to the cylinders if the below vavle was failing?

[4agte]

is that the abv?

[mic*]

ABV stands for?

A.... Blow-off Valve?

I dont know its name, and i am assuming its purpose. Lets just say that is what its called. Now can anyone tell me if i am right, and how to check it with a multimeter...

[oldcorollas]

air bypass valve..

it looks similar to the 4AG ones... see if it connects to the pre SC air and the manifold...

celicaboy_2000
Re: WTB: an air bypass valve(ABV) off of a 4agze or 1ggze Sun, 04 July 2004 18:33

I might have a ABV of a 1GGZE but its not electronic just works by vaccuum boost.

not exactly related, but here for info later

page on 4AGZE pulleys (so i and others can find later)
http://www.mr2supercharger.com/SCpulleys.html
nevo cusco hks pulley

[mic*]

You can see that it connects pre SC, and the bottom does join into the manifold.

You can also see though that it appears to have an electrical connection...

...Going to play with it... TTFN

[c2888]

The engine does indeed spin the freewheeling supercharger if the bypass doesn't open.
I remember seeing it spinning on my car, aw11 engine.

read about the 4agze system here
http://shell.deru.com/~sgn1/AW11/Scnotes.htm

dan

[Grant]

As already mentioned it is the Air Bypass Valve NOT a blow off valve. It's primary function is to by-pass air around the blower when the clutch is disengaged. It's controlled directly by the ecu and will start to close just before the blower clutch engages. This causes the blower to start spinning (before the clutch engages) to reduce shock loading. Some people find by routing the vacuum tube directly to the manifold it gives better response. Try it yourself and see.

[oldcorollas]

. It's controlled directly by the ecu and will start to close just before the blower clutch engages. This causes the blower to start spinning (before the clutch engages) to reduce shock loading.

really? do you have any other inormation about this, ie kinda more official docs, or confirmation about the ECU outputs?
am curious to see this substantiated...

[Ben Wilson]

There's no electrical connection on the mr2 ones, they are completely passive. They simply open when they see a vacuum or more than 8lbs of boost on the inlet line.

[mic*]

...So if you boost over 8psi, the ABV opens & bleeds air backwards into the intake manifold before the SC, acting like a wastegate sort of? I dont think i understood you right Ben, how does a passive valve allow air to pass both ways???

I didnt get the chance to look at it last nite, but it appears to have an electrical connection - not sure tho. But dont think the ECU would switch the ABV first tho. It would be great to have the SC already spinning, but if the ECU uses the ABV to effectively "spool up" the SC it would have to;

-Sense the load through TPS & manifold (foot going down)
-Send appropriate response to ABV
-Allow time delay before engaging clutch

It possible, but the way the car feels, not probable.

[Ben Wilson]

Sorry, I stuffed up a little in my description, it opens if it gets 8lbs on the face of the valve (the pressure blows it open), or if it gets a vacuum on the diaphram.

They look a lot like a low budget external wastgate inside.

The classic ABV mod moves the vacuum signal to after the supercharger, so you've got boost holding the diaphram shut, so the valve can't blow open.

[mic*]

I dont see the purpose of Toyota setting the thing up to act as a wastegate, unless they were real lazy with sizing the SC.

A turbo can spin at any speed relative to rpm's and can overboost, hence the need for the wastegate to control boost. The SC spins at a set ratio to rpm's and i cant see how protecting a bullet-proof 1G from an extra 2 or 3 psi is a worthwhile/necessary excercise.

Shoulda always just been a straight vac-valve around the SC.

Now i just gotta go find out if mine works... Since someone says the SC will freespin from vac if the ABV dont work, makes me think mine is shot, coz ive noticed my SC will spin at about 4500rpm (or so) when i get under the bonnet & free-rev it...

[Ben Wilson]

The SC spins at a set ratio to rpm's and i cant see how protecting a bullet-proof 1G from an extra 2 or 3 psi is a worthwhile/necessary excercise.

Toyota love double or triple redundancy, back when I was running a stock ZE I removed a lot of junk from the engine bay with no noticable difference...

In my experience, ABVs very rarely fail.

[mic*]

Yeah well thats what i would have thought - if it is completely passive there is not much that can fuck up... Id rather it was fucked tho, it means i have a real means to fix my fuel consumption ...

[Ben Wilson]

Unplug your supercharger?