4AGZE Blow off valve (TB after s/charger)

[Ben Wilson]

It can go away (mine has anyway).

[TurboRA28]

So just a blank plate or something?

[Ben Wilson]

You can either put on a blanking plate and a welsh plug in the hose then remove the valve completely, or just jamb a 20c piece into the hose.

[TurboRA28]

Sorry i really need to get up to speed on how SC's work.. But on the blanking plate if i made one up, could you incorperate the blow off valve into that plate? Is that after the SC outlet?

Really appriciate your help mate! Will need to give more rep

[Ben Wilson]

The ABV hooks via a hose and a plate. The hose for the ABV is on the supercharger outlet pipe, you could probably hook up a BOV to that hose (it's 1" OD IIRC). You'll still need to build up a blanking plate for the other hole - Thinking about it, you could probably plumb the BOV back to there, that would be elegant.

There really isn't room to play down there in a mr2, I'm not sure how much space you will have in a T18.

[TurboRA28]

Hmm that sounds like a option.. So the inlet to the BOV would come from the 1" abv hose, then the outlet of the BOV would go to the blanking plate..

[Ben Wilson]

Yep - That should work, it might pay to check it first though.

[jonra23]

To get best throttle response put the BOV as close to thottle plate, especialy in an intercooled system.
Also set it a reasonable amout higher than the boost that you are running, it is only to stop an excess pressure spike damaging componenets or blowing a hose off.

[mullett]

The big problem is searching for things like BOV and ZE - either the forum sortware ignores them or there are to many hits.....

If your search term is too short, add an '_' to it. So instead of TB, you search _TB_ Seems to work fine, and gets around the 'too short' thingo. Works for me

If you've changed the position of the TB etc anyway, and you're running aftermarket managment, I'd be keen to re-do the piping too and from the supercharger to make it less restrictive and neater. In that case, get rid of all the stock plumbing, work out what vacuum/pressure lines you need, and make up nice new pipes with fittings for the vacuum lines (after the TB). In the process, you can make mounts for the BOV and anything else you want to add on, and there's no extra crap to get in the way. The stock plumbing around the SC12 takes up heaps of room....

RM.

[Ben Wilson]

If your search term is too short, add an '_' to it. So instead of TB, you search _TB_ Seems to work fine, and gets around the 'too short' thingo. Works for me

Sweet - I'll have to try that.

If you've changed the position of the TB etc anyway, and you're running aftermarket managment, I'd be keen to re-do the piping too and from the supercharger to make it less restrictive and neater. In that case, get rid of all the stock plumbing, work out what vacuum/pressure lines you need, and make up nice new pipes with fittings for the vacuum lines (after the TB). In the process, you can make mounts for the BOV and anything else you want to add on, and there's no extra crap to get in the way. The stock plumbing around the SC12 takes up heaps of room....

It looks heaps better, but it's heaps of work and makes SFA more power....

[TurboRA28]

I'll have to take some pics of my mates 4agze t18 as with the throttle body move everything was neatened up a lot and custom pipes etc.

thanks for all the help with the BOV queries.

[mic*]

I might be a bit off base here, but what does a BOV do that the ABV doesnt. I though flow perhaps, but if you use the existing diameter plumbing, Will the valve itself in the BOV flow more? I thought they're like the same thing basically...

Anyway... Its sounds cool on Ben's (remembering his lil sample vid...) but, i cant see a big need for it, above and beyond what the ABV already does. The lobes arent fragile like compressor blades, and an SC doesnt have spooling issues.

Did you measure any intake charge temp differences Ben?

[mic*]

By the way, im tryin to find what oil to use for Toyota SC's...

I have some Castrol VMX 80 Manual oil...? No?

"oil" is too common &/or short.

[mullett]

search _oil

I think a very thin gear oil is what people usually use, but I'd get down to Holden and get some SC oil from their commodes. It's about 1/4 of the price of the Toyota SC oil, and apparently the same stuff...

In regards to the ABV question, in the factory setup the throttle body is BEFORE the SC, so there's no problem with venting excess air, because when the throttle is closed there's no air for the SC to pump, so no air needs to be bled off. With the TB AFTER the SC, when you close it the SC keeps pumping 10psi or whatever, which has to go somewhere, I guess if it got extreme enough it'd blow the butterfly out of the TB, or at least bend it, because unlike a turbo it doesn't stop spooling hard when you back off...

RM.

[Ben Wilson]

I might be a bit off base here, but what does a BOV do that the ABV doesnt. I though flow perhaps, but if you use the existing diameter plumbing, Will the valve itself in the BOV flow more? I thought they're like the same thing basically...

Anyway... Its sounds cool on Ben's (remembering his lil sample vid...) but, i cant see a big need for it, above and beyond what the ABV already does. The lobes arent fragile like compressor blades, and an SC doesnt have spooling issues.

Did you measure any intake charge temp differences Ben?

The ABV only opens about 3mm maximum and the internal passages aren't pretty. It won't flow any substanital amount of air.