lower boost pressure ????????

[Steeb]

you can make a home depot racing manual boost controller. my friend had one on his sr20det cuz somehow slipped his mind when he was swapping it in his s13 240sx. just get something like this and attach hoses to it and your turbo system

[mrspanky79]

not all turbos use a spring to controle boost most use a stock controler and some the ecu even changes boost leaves under different loads. Curt had a good thread going on some of the different types there are. And if you look at how the turbo xs or any other boost controle of this type you will see that the hose on the turbos go's to the controler and then a hose go's to the actuator(sp) and there is no other hose so where dos it bleed this extra pressure off to. It dosnt all they are is a valve and when the valve sees the pressure you set it to it opens set off the actuator opening the waste gate. The stock set up on cars works the same way just you cant ajust them by turning a screw.

[JWMotorsports]

You are partly right and partly wrong. You are right about some cars using the ecu and a solonoid or stepping motor to vary the boost while under different loads. I can't honestly say there is a wastegate system on any stock turbo's I've seen. All the ones I've seen or heard of ALL used a sprung swing arm wastegate. The wastegate has a spring in it and the springs tension sets the minimum boost pressure. The only possible way to lower the boost pressure below the springs setting is to change to a lighter spring. If you had no spring in the waste gate the turbo would take till Christmas to spool due to the wastegate would just flop open. If you didn't have a vacum line routed back to the waste gate it would either spike to destruction or stop building boost when the back pressure got to high. The only other way boost pressure can run below the springs setting is if the spring was weak or the waste gate was stuck partly open, also could have a damaged turbine or a restriction in the intake stream. The eclipse is a car I know, just put a 16g on my brothers 1st gen talon. The DSM's have the sprung dash pot swing arm style wastegates. They also have in addition a solonoid controlled by the ecu. If you remove the restrictor in the vacum line right there it will give you a few extra psi. Also the other thing with DSM's is the stock boost guage is basically for looks and doesn't read worth a $h^t when it comes to accuracy.

So yeah you could have ran a lower boost pressure, but it wasn't because of the boost controller! Ethier you had a problem with in the turbo system or your boost guage wasn't reading correctly.


Yes there is a bleeder style system. They are a manual type of boost controller that bleed part of the pressure off the wastegate line to the atmosphere. They were the first type of boost controller made. They originated from aquarium bleeder valves. They work but are a pain in the a$$ due to the fact they have to be installed close to the wastegate, adjusted from under the hood, and are notoriouse for spiking when running high pressure.

<small>[ January 07, 2004, 08:33 AM: Message edited by: JWMotorsports ]</small>

[mrspanky79]

yes they all have springs to keep the waste gate close but they are not all set for boost leaves just what it needs to keep the gate closed. And im running a auto meter gauge on a turbod v6 with 2 diffent t25 on it(one for set up and testing while i rebiult the other, yes did it my self plus everything else) and both turbos showed the same on the gauge and ajusted the same.

[mrspanky79]

oh ya that remineds me if any one is looking for a fuel presure gauage i have a secound auto meter carbine fiber gauge not opeaned that im going to sell.