Dawes Valve setting

[ThomasWatson]

Hey all just wondering whether this is right or not my gu when driving along seems to build boost ridiculously quick and therefore I change gears to prevent over boosting but it sucks on hills

What can you suggest do I tighten or loosen the. Dawes valve

[BillsGU]

The Dawes valve sets the maximum amount of boost. The needle valve adjust the spool up rate of the turbo. It shouldn't over boost if you have the Dawes valve adjusted correctly (approx 16 PSI) - it can vary slightly.

[ThomasWatson]

So I just need to close the needle valve a little?

[BillsGU]

Can't remember which way (open or closed) as its been a while since I installed mine. I know I played around with it for a while until I found the spot I wanted. Just drove it down a quiet country road and stopped (as my needle valve is in the engine bay - some people instal it in the cab), adjusted the valve and drove on again.

[ThomasWatson]

Yeah mine is under the bonnet too just didn't want something for someone that didn't know what it was to play around with

[ThomasWatson]

I want to allow more vacuum before the turbo kicks straight in right so the actuator arm should drop down a little more?

[mudski]

If you have a dawes valve you shouldn't be over boosting.
Need some figures mate to make it easier to help on what settings you may need.
A starting point is 15psi, or whatever your capable of getting before you hit limp mode, and then 10psi at 100k's.
Every car is different though so you might need slightly different settings.
The higher the boost the harder it is to keep the 10psi at 100k though too without risking too much down low lag.

[threedogs]

Idle your Patrol with the needle valve closed and watching turbo actuator arm slowly
open up needle valve until arm falls away then turn needle valve 1/2 turn back and lock
in position, this is only ball park, I did as Billsgu did and adjusted it over a period of
time till I got it where I thought it was spot on.

[ThomasWatson]

I have it set now to what seems better and it holds 10psi at 100 fairly well tweeked a little more just to prevent down low lag as that will bring up temps and it's hard to watch without a pyro gauge but I'm still waiting on my exhaust before installing

[mudski]

You will know when you have hit the sweet spot. I had it on mine then I went and ramped my boost right up, changed the air bleed line to the needle valve from the resonator box to boost from the engine and I had to start all over again. Finally got back but now having lag issues because of the high boost. Why I decided to mess around with it in the first place is beyond me...