manual boost controller question

[Rodd1s]

manual boost controllers... particularly the cheap ebay ones, i can understand how they can increase boost pressure by limiting the amount of pressure getting to the wastegate actuator, but, and its a big but... are they able to reduce boost pressure?

say, for instance, if an internal wastegate is set to 12 psi can these controllers be used to lower it to say 10 psi or more? cos i know how the internals of the controller works, but i just cant see how/if they can lower boost.

or if anyone else has any ideas for how to lower the boost of an internal wastegate other than fitting an extra external wastegate please let me know.

edit: after further reading, those ebay boost controllers cant lower boost pressure, so never mind answering that.

[jidasas]

Are you able to remove the wastgate actuator? If so you may be able to either change the spring inside it or get a completely new spring? Seems that if the pressure causes the actuator to open the wastegate then if you added washers behind the spring it would cause the spring to already be preloaded with some pressure and make the wastegate open sooner? But using washers may not be a stable way as it could feasibly cause some boost to leak by the wastegate and then your turbo would take longer to spool up.

Jimmy

[PrecisionBoost]

They make all sorts of actuators.... you should be able to get 7 PSI, 10PSI

Sometimes you can configure the actuator to open earlier by adjusting the length of the rod.

That is to say the pressure on the gate is related to compression of the spring.... so if the rod is longer the boost will be higher before it pushes the gate open..... if the rod is shorter then it takes less effort to push it open.

I don't know off hand what the adjustment rate is.... I have to imagine it's a couple of PSI each way.

Like I said.... sometimes you can do this.... it depends on the style of the actuator.


Ideally you want to get the actuator with the minimum boost levels you want to run ( 10 PSI ) then used a controller to increase the boost.

[Rodd1s]

ive read and seen all sorts of ways how to physicaly modify the wastegate actuator and the rod connecting to the valve, but its not possible on this style ive got, everything imaginable about this wastegate is internal.