Help!=) Boost Wont Turn Down!

[restless]

Hi guys bought another r33 s2 .. anyways I tried to turn down the boost and the gated ts boost controller is turned down all the way and it boosts to just under 1 bar.... I even took the ball and spring out. I wanted to ask what sort of things would cause this.... Such as wastegate, intercooler hose cracks, spark plugs, im not sure..... could it be the cats be decated...

All i want to do is run 12 psi max so does anyone have any idea how I can reduce boost? I was thinking maybe the stock bov would bleed some the excess boost off.......

anyways mods are

FMIC

Exhaust turbo back split dump restrictors been removed...

TS boost t

splitfires coils

HKS ssqv bov no (no idea if its real looks real)

boost also goes up and down? eratically somtimes under hard acc

Any help

cheers

Edited August 28, 2012 by restless

[Hadouken]

what turbo? what actuator?

1bar actuator would result in 1 bar min boost

[restless]

Im pretty sure its standard turbo (could be highflowed) and im not really sure about actuator.. whats the best way to check if its been changed?

[Hadouken]

is it shiny?

Nah i dunno

[restless]

lol

[Moodles2]

Nissan used a restrictor inside the vacuum piping (one going to the wastegate actuator IIRC) to bring boost down on GTRs (about 8-9psi with it present, 14.7psi with it gone)

[restless]

yeh its missing the restrictor, previous owner would have taken the hoses off so does that mean if i want to run 10-12 psi I would have to put them back in? I thought that the Boost t was able to reduce boost until the standard wastegates presets? It also only happens in high rpms after 4500-7000

Edited August 28, 2012 by restless

[Moodles2]

You cannot reduce boost lower than the wastegate is set to, period. Only way is by physically restricting the lines

[mad082]

restricting the boost line will increase the boost pressure, not reduce it. restricting it is what a boost controller does to increase the boost.

[Moodles2]

Restrictor in the wastegate piping (between boost controller and wastegate actuator) should bring the pressure down and make the wastegate open much later. Pretty sure that's how GTRs are setup from the factory.

[Tommy Kaira RL]

Restrictor in the wastegate piping (between boost controller and wastegate actuator) should bring the pressure down and make the wastegate open much later. Pretty sure that's how GTRs are setup from the factory.

I think you have it mixed up. If you open the wastegate much later then its going to increase boost. The earlier you open the actuator gives you less boost.

[mad082]

I think you have it mixed up. If you open the wastegate much later then its going to increase boost. The earlier you open the actuator gives you less boost.

this. the later the wastegate opens, the higher the pressure will be when it opens. if you restrict how much boost pressure the wastegate sees then the end result is higher pressure on the cooler piping side than on the wastegate side. which is exactly how a boost controller works. or if you complete block the hole it will give you unlimited boost. a few simple way to increse the boost on a car with a restrictor in the hose to the wastegate is to solder the restrictor closed and then drill a smaller hole in it.

in the case of the r33 gts-t, the solenoid that they have bleeds off air between the cooler piping and the wastegate, so the wastegate sees less pressure.

[XKLABA]

Restrictor in the wastegate piping (between boost controller and wastegate actuator) should bring the pressure down and make the wastegate open much later. Pretty sure that's how GTRs are setup from the factory.

on the GTRs there is a line that runs from the underside of the plenum at the back near the brake master, that line runs under the plenum to a T from there one side runs around the back of the motor to the waste gates, the other side runs to the boost solenoid then back under the plenum around the back of the motor to the inlet pipe for the back turbo

the restrictor in the line from the T to the solenoid in creases the pressure between it and the waste gates there for opening the waste gates sooner, removing it reduces that pressure which in turn keeps the gates shut longer giving more boost

OP, try removing the controller and putting at straight joiner, that will give you waste gate pressure, what ever that might be

[restless]

I was thinking its boost creep and maybe the split dump was causing it.. I heard if I put restrictors on the exhaust it will fixed it or even porting the internal wastegate. could help? I have heard people use a Greddy profec b II which controls the gain to counter the waste gate creep../? anyone have the same issue? I also put it back to stock but its missing the restictors so it just cut out at 5000rpm when in high boost mode... anyways ill post some pics maybe the hoses have been connected in a bad configuration

Edited September 2, 2012 by restless

[restless]

Hey people I fixed it!. ... I got a silencer and put it into the rear muffler and it runs prefect!!!!!!!!!!!!!!! so I guess exhaust was to free flowing...

Edited September 4, 2012 by restless