Disabling Vsv?

[MattMR2Turbo]

I've just been reading on IMOC about disabling the VSV. Its not quite clear on how to do this and what the benefits/downsides to it are.

Please could someone post on here and let me know what it's all about? I have a Rev3 turbo and apparently it's a very good thing to do on these engines?

Thanks in advance

[BenL]

The T-VSV is nothing more than an electronic bleed valve which is controlled by the ECU. It's function is to increase the boost over the turbo actuators set pressure of 7psi.

When your engine is cold, or knocking has been detected the T-VSV remains closed and your max boost is limited to the base 7psi. If all is well and the engine is up to running temp, the T-VSV opens and bleeds off a little pressure back to the inlet manifold to increase the boost to 13psi.

If you disable the T-VSV you will need either a bleed valve or ideally an electronic boost controller to increase the boost back to the factory 13psi. Once you have done this you remove one of the ECU's safe guards against engine damage, but because the ECU also closes the T-VSV when the external temp drops below 5 degrees, you will also get more consistant cold weather running.

Unplugging the T-VSV is the quickest way to disable it, however that means climbing under the car (it's located under the inlet manifold). A much easier way to disable it is to cut the vacuum pipe from the turbo actuator which disapears off under the engine and plug both ends.

[MattMR2Turbo]

Oh ok, I've got ableed valve on at the moment so it will already be disabled

So what's the difference between my bleed valve and a grainger valve? I've hear that a grainger valve is 'better' but I can't see how it can really make that much difference as both devices route pressure away from the actuator? Surely both are good enough to release enough pressure to 18psi where fuel cut comes in?

Cheers

Matt

[Bibbs]

the Bleed valve lets air out before you hit max boost .. the G-valve lets air out only when you are at max boost.

so the Bleed is adding time to your spool up ..

And the hose you stuck the valve in goes to the actuator .. there is another hose from the actuator - this is the hose you wanna cut and block.

[MattMR2Turbo]

Oh right so the grainger valve will be better then?

I only use the bleed valve at the moment to get full boost because in the cold weather etc without it I don't think I've ever seen it boost fully :(

How much will I pay for a grainger and is it easy enough to set up? Take it it goes in the same place as the bleed valve?

[Bibbs]

should be a straight swap for the bleed ..

and it's a matter of winding it in for more boost .. setup the same for the bleed - get in, razz it, read the boost, tweek the valve, try again.

[MattMR2Turbo]

Ok cool sounds good. Where can I get one from and how much will it cost?

Just wondering, will my rev3 cut the fuel if the boost exceeds 18psi? I'm setting mine up by the dash boost gauge that's all. I'm pretty sure the car hasn't got a fuel cut defender either.

[Bibbs]

Argh !! not the dash guage .. that's more vague, than a vague thing on a vague day, in a bowl of thick soup in a fog.

Before you start upping the boost, get in a FCD and a G-Valve (from Rogue Systems) .. and set it up safely ..

[MattMR2Turbo]

Ok, so the fuel cut defender will allow the car to boost over 18 psi yes?

So I need a proper boost gauge to monitor things also?

Best get this done sharpish then I'm paranoid about not using my car safely!

Are there any decent pods for a boost gauge that will look 'standard' in the MR2?

[Bibbs]

FCD will allow a LOT more boost.

Yeah .. the stock guage is an ON/OFF affair ..

Have a look at the pic of my dash I posted .. there is a Omori guage in the stock location .. subtle, but oh so cool ..

[Jimlad]

I'll second bibbs... I have the same gauge in the same location... very nice !

[KiwiMR2]

Ok, so the fuel cut defender will allow the car to boost over 18 psi yes?

Yes....but to be honest you probably won't need too...and even if you do go above 18psi imho only do so on a nice cold night or day and not all the time.....unless you have all the supporting mods to do so :)

So I need a proper boost gauge to monitor things also?

Would be a very WISE idea.

Are there any decent pods for a boost gauge that will look 'standard' in the MR2?

Most of the one's iv'e seen are clip on ones......you could go custom like me, I have a clip on molded with the STOCK a-piller in the factory position.

Cheers

KiwiMR2

[pizza boy]

Im quite surprised that your cars previous owner fitten a bleed valve to mess with the boost output yet didnt fit a boost gauge to measure accordingly. Its quite worrying actually.

[MattMR2Turbo]

Can you point me to where the picture of your dash is please Bibbs? Either that or you can send the picture to matthew.law@cambridgshire.gov.uk.

Cheers

Matt

[Bibbs]

Thread

Not a good pic .. I'll take another .. over the weekend probably ..

But the guage is in the stock location ..