Lower Boost

[V8Celica]

I've been trying to think of a way to run 5 psi boost when my wastegates open at 7-8psi
I'm thinking if I hooked up an electronic boost controller to an air receiver and the compressor off the crowns air suspension and regulate the pressure to about 20 psi that way when I reach 5 psi the EBC will give the wastegates 20 psi.
Any thoughts? Should it work?

 

[Peewee]

You should be able to change the springs on the wastegates so they open with less pressure.

 

[V8Celica]

There a sealed factory actuator for the internal wastegates.

 

[Peewee]

What Turbos?

 

[gloverman]

As Peewee said change the spring. Normally they are cripped together. Undo the crip and change spring, I have done this to up boost. What you are trying to do is releive the spring tension. Another option is to cut the connecting bar and make it longer. As this is a bit hit and miss so if you might want to make the bar adjustable(have a look at other turbos you will find some that have adjustable bars). This you could save alot of time and money. Good luck Cheers Kelvin

 

[V8Celica]

What Turbos?

Series 4 RX7

 

[chrisman]

it sounds like it might work--but it shure sounds complicated and expensive .. all you would need to do is get some springs and have them help the wastegates springs--a couple of dollars each..
remember in the wastegates is a spring and the boost is pushing against the spring to open the wastegate.. if you add a helper spring on the outside of the wastegate, your wastegate will open sooner..simple and effective.. make sure you get 2 similar springs if you have 2 turbos and make sure they are mounted similarly on the turbos..
i have been using springs instead of wastegates on rdms car for a while now--they work fine and are very consistant..rdm changes the boost he wants by "stretching" the spring ..
i know it sounds kinda simplistic, but i would say save your money for the important parts --like pistons, rods, etc..

 

[88Alltrac]

Do you have a BOV? You can bleed off some compressor air using it instead of dealing with the turbine side. Just open it a bit more untill you get the desired boost. That or bypass the wastegate, you could drill a hole and re-route gas back into the exhaust after the turbo. Either way, this is not easy. If you wana do it the easy way, use a helper spring.

 

[edz]

it sounds like it might work--but it shure sounds complicated and expensive .. all you would need to do is get some springs and have them help the wastegates springs--a couple of dollars each..
remember in the wastegates is a spring and the boost is pushing against the spring to open the wastegate.. if you add a helper spring on the outside of the wastegate, your wastegate will open sooner..simple and effective.. make sure you get 2 similar springs if you have 2 turbos and make sure they are mounted similarly on the turbos..
i have been using springs instead of wastegates on rdms car for a while now--they work fine and are very consistant..rdm changes the boost he wants by "stretching" the spring ..
i know it sounds kinda simplistic, but i would say save your money for the important parts --like pistons, rods, etc..

Helper spring is ok, I would go with pulling it apart and fitting a lighter spring. Other options, shorten the arm or change the location point to the push/pull rod, add a lever to halve the load.

 

[thad]

The easiest thing to do would be make the actuator arm adjustable. I cut mine in half, tapped both ends, and used a 1" long nut with two lock nuts.

The other option is to rig up another wastegate actuator to work on your turbo. You often have to rig up the actuator if you clock the turbo much, anyways.

Some cars that come with wastegates at 5-6psi:
84-88 nissan 300z t3 .60ar/.63ex. - 5psi
Most all chrysler 2.2l turbos w/ the goofy t3 all spool at - 5.5psi-6.5
87-88 rx7 twin scroll turbo= 6.2psi
Saab turbos 80-82.5 with .45 trim .42/.48 T3 4psi
Saab turbos 82.5-either 86 or 87 with .50 trim .42/.48 T3 5.5 psi
.60/.48 and .60/.63 AUTO(only) T3 Ford 2.3 turbos from 84-86 are 6 psi