VVTI Turbo

[bullstarz]

I have a 1uz vvti engine which is in the process of being put together with a turbo.

The inlet manifold has the Toyota Acoustic control thing but this work a on vacuum operating ports under certain engine speeds, loads and throttle position. The thing is will it may work with a N/A engine, forced induction on the other hand throws up a few problems.

When the ports are meant to open mine will be closed as there will be no vacuum at full throttle on boost.

Is the Toyota system, worth keeping, not using, adapting or just removing with a turbo.

Has anyone any ideas.

 

[gloverman]

Are you suggesting the system is open at low revs and closed at high revs and WOT? Have you got info on switching points and parameters?

And have you considered the one way valve in the vacuum supply system before the reservoir which maintains a constant vacuum supply.

 

[hiluxfan]

Hi!
If I remember correctly there is a small solenoid valve activated by the E.C.U. It is not only determined by vacuum. As Gloverman said, you will definitely need a one way valve to the reservoir. If there are no vacuum leaks the system should then work as normal. Are you going to use an after market E.C.U?

 

[gloverman]

There is already a one way valve in the system.

 

[hiluxfan]

Yes of course. Now that I think about it, there has to be one.

 

[bullstarz]

Yes there are at least two vacuum sensors/switches. The original system opens the valves when the ecu lets it, as theres loads of parameters. But the main one is on high throttle openings.

When these valves are closed the air is supposed to cause a induction spiral and increase torque, fuel economy and reduce induction roar.

As there will be only a depression when the throttle is fully closed, on a forced induction engine, this system won't work as it should. So is it worth keeping, adapting or junking.

The engine is still out and easy to work on. ITB would be the way forward but hard to set up and expense.

 

[gloverman]

I have seen the VSV under the intake manifold which controls the variable intake runners and there is a VSV for the tank purge system. What others do you guys get?

The variable intake runner length system works fine with a turbo and adds really good low end torque (just as it does on N/a engine) I get a guide for the switching just point like any other, Dyno run with and dyno run without then set at crossover point.

The Vacuum canister holds enough vacuum to switch the intake runner VSV. The VSV opens at low speed (or high Vacuum) which closes the manifold flaps. At higher revs (lower vacuum) the VSV closes which allows the manifold flaps to open.

On other engines with similar ideas/functions I have simply run the system on vacuum and boost with really good results. I do prefer having the control though.