Fitting A Relief Valve

[GT4 BOOSTER]

it finally came today , due to xmas post

i am wondering about the pipes for fitment - do they have to be 1 mtr long , can they be any length as long as its reachable for adjustment.

will 6mm petrol pipe reinforced be better than the silicon pipe

[Bibbs]

This a MCB?

Any length, as long as you can get to it easy.

It is a pressure hose, but you got to think the temps arount the turbo, I used double threaded hose.

[GT4 BOOSTER]

thick woven rubber petrol pipe it is then . THE PIN HOLE IN IT , i take it has to be kept clean at all times ????

can't wait till its fitted - ,let there be more BOOST .

[Sketchy]

thick woven rubber petrol pipe  it is then . THE PIN HOLE IN IT ,  i take it has to be kept clean at all times ????

can't wait till its fitted - ,let there be more  BOOST .

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YEP :D

Couple of point for fault diagnosis with MBC's

My boost rises and falls a little... This is fairly normal until the ball bearing seats properly into the brass body of the valve. A few hundred miles are often needed to settle it in

The boost hits my preset level, then falls, then gradually rises again up to the preset level...

This is usually caused by the small (0.7mm) vent hole in the knurled section of the adjuster being either blocked or too small. Firstly, check the vent hole is not blocked, by removing the valve and inserting a small piece of wire into the hole, then blowing through the hole. You can increase the size of the hole as much as you require, but generally, going above 1mm is pointless, as it tends to reduce the speed at which the boost level builds. Try 0.8mm

The boost hits my preset level, then creeps up slowly by 1-2psi as the revs increase...

The diameter of the hoses going to and from the BCV is too small. You need either 5mm ID Samco vacuum hose or 1/4" fuel hose from your local motor factor.

The boost rises quickly and I get a "boost spike" - this is where the boost rises above the level you need for a fraction of a second...

It is normal for the boost to spike fractionally, but the boost level should stay +/- 1psi throughout the range. If it spikes more than this, two things can be tried - 1. Move the valve closer to the actuator - ideally within 3-4" (75-100mm). 2. The input (usually taken from the throttle body) can be taken from somewhere closer to the turbo, ideally the turbo outlet. Unfortunately, this may require the turbo to be removed and a 1/4" barbed boss welded on

I cannot get the boost level low enough...

This valve, when the adjuster is backed off completely, allows free flow, so you have another problem!!

[GT4 BOOSTER]

ta sketchy.

[Sketchy]

ta sketchy.

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No prob :D