Boost spike prob (halp!)

[Volcanix]

Hi there guys

I was wondering how to fix a problem im having my secondary turb is acting funny in the fact that im gettng a boost spike to 16psi for a second then holding 11psi for the rest of the rev range it doesnt fluctuate once it drops and its completly std its a BD5 rs legacy , what ever could be wrong with it?

[Guest boostin]

Subaru boost control normally peaks then tapers off. You're not confusing this for a boost spike are you?

[Volcanix]

why would it pull all the way to 16 then taper off at 11?

[Guest boostin]

To protect the engine at high rpm's.

[Volcanix]

sounds fesable, can anyone for a coupla brewskis come over and help me confirm this

[agent]

My BG5 has just started doing this on Saturday, Im sure it had never done it before. Then I went to the mountain and now it just sits on 7psi on both turbos and wont go any higher, so frustrating!!

[Koom]

 boostin said:

To protect the engine at high rpm's.

You're more likely to get detonation at peak torque than peak revs.

It'll spike because thats the easiest way to make it respond early. Its difficult to make a control system reach its intended level without a spike if you want it to get to that level as quick as possible. To get it to boost without spiking, it'd have to come "on boost" much later without them upgrading to a much better system of controlling boost.

Does seem like quite a high spike though.

[mattapo]

i should have mine back tomorow if you wanna compare

[Volcanix]

might do ae man, as for agent i had that happen to me driving to dunedin once middle of trip after boosting normally it decided to drop to 7 and not do anything it felt weird i restarted it and the prob didnt go away untill it has sat over night in dunners lol, and ive not seen it again lol

[agent]

I reset the ecu and now it boosts fine, but sometimes at high boost it cuts ignition

[G-unit]

my old TT would boost upto 17-18psi then settle on 15psi and hold that