effecting boost

[eyz closd]

i just wanted to know if the vacume line setup i have currently could be effecting my boost.
im running a single port actuator on my upgraded ct26 which can be seen here
http://www.toyotanation.com/forum/t127132.html
(disreguard the ct26 actuator in the first picture)
since the turbo never came tapped i had to tap into the hot pipe that runs from the turbo to the intercooler.

i have the line running from the port of the actuator to the tap on the hot pipe and the line is T'ed to the valve on the motor which went to the second port on the ct26 actuator.

I know the valve on the motor is a vac line for the waste gate for when you release the accelerator is opens the wastegate but can this setup i have effect my boost or should i just cap off the valve that is on the motor and remove the T on my line and just run the line from the wastegate to the turbo?

[JekylandHyde]

I'm taking the time to write this and I hope you take the time to read it as it is apparent that you are musunderstanding how the whole system works.

Your set up is wrong and you are misunderstanding the function of the valve under the motor.

This line:
"I know the valve on the motor is a vac line for the waste gate for when you release the accelerator is opens the wastegate"
Is completely incorrect.

When you let off the accelerator the BPV/BOV opens, that is the valve on the hot pipe.
The wastegate would CLOSE.

It's very important to understand what the pieces are doing and why.

The turbo builds boost by exhausts spinning the turbine wheel. As the turbine wheel spins, it spins the compressor wheel which compressed the intake air to make "boost." Once you hit the deisred boost level (let's say 7 psi), you need to BYPASS the turbine with some of the exhaust; otherwise it would build boost indefinitely until you went BOOM.

So, you start boosting and you get to 7 psi and the wastegate opens and allows some exhaust energy to go around the turbine sos it does not make more boost. This is how you control it to 7 psi.

The question is, how does the wastegate open? It opens via the wastegate actuator which reads boost. The actuator is set up to open under a certain boost level. So, in stock form, if you only had the line going from the compressor to the left nipple ofthe actuator you would boost to 7 psi. That what the CT26's actuator is set at.

However, when conditions are optimal (good temperatures, no knocking, etcs) the ECU allows you too boost up to 9-11 psi. How does it do that? Through the T-VSV (turbo vacuum switching valve). That is where the second nipple goes to.

When life is good, that valve opens and allows some of the boost pressure to bleed off, past the actuator so it does not open until a higher boost. It basically allows you to lie to the actutaor that you are not at 7 psi quite yet, even though you are. When you hit 11.8 psi or you over come the T-VSV and the wastegate opens.

So, if you cap off the line to the T-VSV, you will be at whatever boost level your actuator is set for. From there, you can add a boost controller so you can control boost.

I hope that helps. Let me know if you have any questions.

[Zero turbo]

Hey MR.j&h do you think that getting a external wastegate and weld it to the exhaust side of the turbo (ct-26 completly sock) could be usefull or not and why?? cuz when I bought my car it came with this setup and still has it.The wastegate dumps to the air.

[eyz closd]

iight Thanks J&H i got it now im just going to cap off the T-VSV. that explains why i get the boost creep sometimes. because of the "optimal conditions".

J&H could u take a look at the link to the other thread in my question. which shows my turbo and tell me what you think the maximum boost that turbo could take before it goes boom. and how much boost i should be running with my current mods.

Thanks again,
Sean