rb25 boost creep issue

[ShaneO'F]

has anyone ever come across this?

just put on a hybrid turbo, actuator, new dual chamber stainless elbow, downpipe.. the car is boosting at 1.4 bar until you go flap out and at about 5k revs it creeps til about 2 bar and power cuts.. its definitely not an electrical misfire. all vacuums and IC pipes seem ok.. im wonderintg has anyone had issues where the bigger compressor housing and the elbow not big enough to blow put all the gasses and the back pressure causes the spiking? if I could get an actuator handy id try that but there not easy got Id say for this turbo.. standard ECU , injectors, car has 1.2mm cosworth head gasket and adjustable fuel pressure reg, full exhaust and induction kit is all the other engine mods..

thanks

[nicky h]

Is it a standard actuator or adjustable ?

[slithertooth]

What turbo?

[gem-s13]

Either the actuator is to tight or the turbo elbo is a china one and the wastegate flap cant open enough to cope with the boost corection at high rpm
and with the stock ecu you shouldnt be running any more than 0.8- 0.9 bar id say even after hitting 2ish and cutting you will be looking for pistons very soon ringlands dont like tgat

[ShaneO'F]

hybrid turbo with adjustible actuator.. the flat can open fullt in the elbow, i checked it while twas all out on the ground.. i planned on running it at a bar boost, iv an adjustoble fuel pressure reg, steel head gasket and just built head.. iv 11 bar compression in all 6 clyinders.. i only drove it over the road booted hard once so iv no damage done.. kinda scratching my head as to what to check now yano lads

[japstuff 2]

as gem said u will bust pistons without a map as a standart ecu can just about deal with 0.8-0.9 on a standart turbo
as for the boost i had a simular prob before due to the hole behind the penny/wastegate flap being to small welded it up went external wastegate and was 100% after that