Boost controller???

[Conners]

Hi guys, new to the forum and rav4 ownership. Anyways iv been trying to install a manual boost controller to my d4d without much success. I vaguely remember reading that these things don't work on all turbos and I can't find the info again can anyone clarify?? Or is there anyone who has been successful in cranking up the boost a bit if so how?

[Chambers]

First, do you understand how a turbo works? The waste gate controls the boost pressure by opening letting exhaust gases bypass the turbine. The waste gate is usually actuated by boost pressure from the discharge side of the turbo.

The Supra has a rubber line running form the compressor side of the turbo to the waste gate. So we would put a manual boost controller "in line" between the pressure side and the waste gate.

So look at the turbo exhaust housing, look for the waste gate actuator. See if it has a line running to it like the Supra:

[Dr. Dyno]

Turbos also work different on Diesels than on gas engines. Boost is limited by the volume of fuel injected not necessarily the waste gate. Until you have enough fuel to overfuel as indicated by black smoke exhaust adding more air won't make more power.

[Conners]

Originally Posted by Chambers

First, do you understand how a turbo works? The waste gate controls the boost pressure by opening letting exhaust gases bypass the turbine. The waste gate is usually actuated by boost pressure from the discharge side of the turbo.

The Supra has a rubber line running form the compressor side of the turbo to the waste gate. So we would put a manual boost controller "in line" between the pressure side and the waste gate.

So look at the turbo exhaust housing, look for the waste gate actuator. See if it has a line running to it like the Supra:

first, this isn't a supra its a rav 4 diesel engine, second i am fully aware how a turbo works. on a rav 4 the compressor output goes to the boost actuator via an electronically controlled solenoid. i have tried to bypass said solenoid with no luck. doing this i get no boost at all untill about 3500 then a spike in power. im guessing without unlocking the ecu, which in itself is a mission on a rav 4 4.2, it isnt possible.

[Chambers]

Yes, I realize its a diesel RAV 4 engine. But a turbo is a turbo, all I wanted to do is cover all bases so the info given was not misunderstood. Just from your question I could not gather whether you had a understanding of how the system worked.

If the waste gate is controlled by a computer then you are correct, you would need to "un lock" the controller or the ECU, either may control the solenoid on the waste gate. If you can get a hold of the factory service manual you may be able to read up on how the boost is controlled and use that to your advantage.

Good luck!

[Dr. Dyno]

Originally Posted by Conners

On a rav 4 the compressor output goes to the boost actuator via an electronically controlled solenoid. i have tried to bypass said solenoid with no luck. doing this i get no boost at all untill about 3500 then a spike in power. im guessing without unlocking the ecu, which in itself is a mission on a rav 4 4.2, it isnt possible.

Interesting, and you are correct the change to add more fuel has to be done via the ECU.
On the 7.3L Diesels like my F-250s it's common practice to disconnect the "vacuum" actually a pressure hose that connects to the waste gate. According to my boost gauge it doesn't increase max boost but allows it to build quicker. In a towing situation the effect is keeping exhaust temperatures under control better on uphills.
Max boost and power is determined by the setting of the chip (Bully Dog or TS Performance that plugs into the side of the ECM) via the knob on the dash. Stock it runs 12-14 psi. With the chip on max, 25 psi.