vnt control = dawes valve

[55eta]

Correct, it should be noted that the dawes device is not a VNT controller.

Brendan

I think you need to look more closely at the link in the 4th post on this thread

[55eta]

Its not used without the ECU.

Look at the drawing on the link the one in with the pictures of the engine bay pluming ,can you se a n75 type valve there ? i think not

[OM617]

Look at the drawing on the link the one in with the pictures of the engine bay pluming ,can you se a n75 type valve there ? i think not

Look at the drawing on the link the one in with the pictures of the engine bay pluming ,can you see where it says "Dawes Valve Fitted With Factory ECU Controlled Vacuum Solenoid".

[55eta]

Look at the drawing on the link the one in with the pictures of the engine bay pluming ,can you se a n75 type valve there ? i think not

Look at the drawing on the link the one in with the pictures of the engine bay pluming ,can you see where it says "Dawes Valve Fitted With Factory ECU Controlled Vacuum Solenoid".

you are looking at the wrong drawing look up the page ther is another click on it to expand it an then read the rest of the page after

[famous phil]

Not sure about the dawes valve but I asked a local turbo specialist that builds hybid turbo's , and was told about the product below would this work for the vnt you have ?

http://www.performance-wise.com/page42.htm

HDI BOOST CONTROL KIT & EVOLUTION BOOST GAUGE

I asked if this needs a signal for the engines rpm's he said not ,

[OM617]

you are looking at the wrong drawing[/quote]
That is the only valid drawing.

Using a single dawes valve alone would be no different than replacing the vacuum actuator with a normal wastegate actuator. You'll get very high exhaust pressure at cruising speeds and there is no way to limit boost to the engine load. It's all or nothing, always trying to get the boost to maximum under any conditions. In a correct system the ECU is only what controls pressure, the dawes valve prevents boost spikes due to the computer and solenoid lag time.

If you want a dawes valve system alone with no computer you must have a way to limit boost in low load conditions. I do this by using 3 dawes valves and two throttle position valves, others use a cable system to move the vanes with an actuator just to limit boost.

Controllers for watstegated turbos do not work the same with a VNT. A wastegate only limits boost pressure, a VNT actuator controls boost pressure.

[55eta]

you are looking at the wrong drawing

That is the only valid drawing.

Using a single dawes valve alone would be no different than replacing the vacuum actuator with a normal waste gate actuator. You'll get very high exhaust pressure at cruising speeds and there is no way to limit boost to the engine load. It's all or nothing, always trying to get the boost to maximum under any conditions. In a correct system the ECU is only what controls pressure, the dawes valve prevents boost spikes due to the computer and solenoid lag time.

If you want a dawes valve system alone with no computer you must have a way to limit boost in low load conditions. I do this by using 3 dawes valves and two throttle position valves, others use a cable system to move the vanes with an actuator just to limit boost.

Controllers for watstegated turbos do not work the same with a VNT. A wastegate only limits boost pressure, a VNT actuator controls boost pressure.
[/quote]

Top off the page there are 7 pictures [of the engine bay] and one drawing ,this is the drawing you need to look at and then note the third line of text that explains the use of said vale without ecu control solenoid

I have now fitted the valve and vnt , it now dose what it said on the box [with regards to the valve] all though the boost is a little high [8-10psi ] when cruising with light throttle there is verey little if nothing in the way off boost spikes /surge  and this is installed on a aaz  ,well impressed for a simple valve and a needle valve  ,it is never going to be as good as ecu control but for the money it is not expected to be but it`s a big improvement on the waste gate turbo i had  and it fulfilled my main goal which was to reduce egt which it did by about15-20% using the same fueling and boost as i had with the w/g turbo  and it did not flood the vacuum system with air as some said it would

[blackdogvan]

That's great to hear; I've been looking at that Aussie plumbing design for some time & have been getting closer & closer to going for it.
 http://www.chaz.yellowfoot.org/Schematic.htm
One thought I had was to use a ball valve attached to the throttle arm in series with the needle valve to get some throttle position input for more boost at full throttle using the vnt arm set screw to limit boost ability at too low of rpm. Full throttle would then close off the needle valve line putting full vacuum to the vnt actuator. At least I think that would work...