Wastegate question

[MobyUK]

Hi Folks. I've been reading some posts around the web concerning wastegate adjustments and I'm slightly confused by conflicting facts.
As I understand it, there are two factors that affect the operation of the wastegate, the spring rate and the spring preload.
The spring rate is fixed by the spring and controls the pressure at which the wastegate is fully open and thus the maximum boost.
The spring preload is controlled by the length of the operating rod and controls, to some extent, the pressure at which the wastegate will start to open.
It therefore suggests that by altering the preload you can affect the spooling of the turbo i.e. make turbo boost start earlier or later in the rev range.
If this is right, is it shortening or lengthening the operating rod that would make the turbo spool earlier.

[siamblue]

HI Moby, i have just adjusted mine, i to couldn't get my head around, but a helpful friend showed me what and how it was done, my wastegate opening was set at 7.5psi that is when it was starting to creep open <<< by a previous tuner, the car was very quick low down, but i wanted to keep my rods straight so i adjusted the rod 2 full turns down and the WG now creeps open at 4.5psi the boost comes in later now, which makes the car more drivable around London,

HTH,

Gary

[daveforber]

Shortening the rod (i.e. tightening the adjuster) will make the turbo boost earlier and increase peak boost. It will also potentially introduce unwanted boost spikes.

How to: http://www.vpcuk.org/forums/showthread.php?t=22786

I'd try an MBC first; you'll want a boost gauge for either adjustment.

[MobyUK]

Thank you both for the info. What is the recommended standard setting for the T5 boost pressure?