Dual Dawes Setup

[Dr Gary]

I am about to connect the plumbing for my Dawes setup. I need confirmation that:

1) The hose from the air filter Resonator connects directly to the needle valve
2) The three ports in the Vacuum solenoid are blocked off

It LOOKS simple, but given the work to get this far, I would hate to screw up.

Thanks in advance

[threedogs]

Have you googled Chaz Yellowfoot for his drawings, very well written as well.
Hard to stuff up, that vacuum solenoid I think I looped to ports together the third went into the air cleaner box
seems so long ago now Boots did mine

[Dr Gary]

Have you googled Chaz Yellowfoot for his drawings, very well written as well.
Hard to stuff up, that vacuum solenoid I think I looped to ports together the third went into the air cleaner box
seems so long ago now Boots did mine
Yes, I have Chaz' write-up, and yes it looks straight forward--just a final check before I disable existing stuff.

[mudski]

I am about to connect the plumbing for my Dawes setup. I need confirmation that:

1) The hose from the air filter Resonator connects directly to the needle valve
2) The three ports in the Vacuum solenoid are blocked off

It LOOKS simple, but given the work to get this far, I would hate to screw up.

Thanks in advance

1 is yes and 2 is also yes.

[threedogs]

whats the reason for the dual dawes set up, I cant see the logic in it tbh.
Maybe Rumjas can fill me in

[mudski]

whats the reason for the dual dawes set up, I cant see the logic in it tbh.
Maybe Rumjas can fill me in

Hi boost equates to higher fuel consumption pretty much. So having two max boost options I suppose you can keep your fuel consumption down.
But it all depends on how you drive your car.
Me. I tend to be hard on the pedal most times so for me it would be a waste to do it. But having said that if I had the time I would fit one up just to see the difference.

[threedogs]

Still cant see the point but thanks,

[mudski]

Each to their own John.:D

[Dr Gary]

Still cant see the point but thanks,
According to Chaz 'write up and recent email correspondence, if I set low boost around 14 psi and high boost around 17 psi, I SHOULD get reasonable economy around town, and plenty of GO with heavy throttle. That setup also (according to Chaz) keeps EGT at sensible levels.
It also prevents boost above set levels, and the factory setup can get really high boost on occasions.
Worst case: it does not perform as documented, and I just reconnect the original set-up or just run a single Dawes to limit boost.
All good fun.:clownredpuff:

[threedogs]

So you would use the lower value boost if touring for example.
TBH never thought high boost meant high fuel consumption.
anything to save on fuel has to be a good thing eh,
Do you know your fuel figures now for comparison?

[big_fletch]

Running the duel dawes setup has a bigger advantage on a vehicle with quite a quick spool rate, I used too run a duel dawes system on my last patrol and running the low boost at 10psi max around town saved more than 1ltr-100. I found running the higher boost setting on the freeway had a better fuel consumption then the low setting.
I have a single dawes in my troll now set for 18psi max and have the spool almost spot on.

Drove too trarlgon last week and averaged 11.5ltrs/100.. Not bad on 33's with 2" lift and roofrack

[Dr Gary]

So you would use the lower value boost if touring for example.
TBH never thought high boost meant high fuel consumption.
anything to save on fuel has to be a good thing eh,
Do you know your fuel figures now for comparison?

I suspect higher boost will use more fuel than low boost (throttle need to be wider open to activate), BUT if boost is too low there are EGT issues. However the higher boost is not why more fuel is used--that happens if the speed increases anyway.
I would NOT use low boost cruising-just let TPS determine high or low at 1.6 volts. If I back off, high boost is turned off.
I completed a 7,000 km trip through QLD, NT, and SA in some pretty bad conditions with a fairly heavy load and roof rack. Overall was 12 l/100. That is about the same as I get around town now.
We shall see !!!

[Rumcajs]

Mine are set at low boost 12 psi high boost 18psi. Depending on conditions I found that keeping low boost on (I have over-ride switch where I can force either mode or automatic via TPS) on cruising will save as much as 1-1.5 L per 100 km. I also force low boost mode when engine is cold.

There is this strange thing about GU 4, where I have better economy in the city than on the open road and I have heard from the others the same thing. (GU4 owners)

It works with needle closed as well so I have very aggressive spool up and handy low to mid range torque doing it this way.

Regards

[Dr Gary]

Mine are set at low boost 12 psi high boost 18psi. Depending on conditions I found that keeping low boost on (I have over-ride switch where I can force either mode or automatic via TPS) on cruising will save as much as 1-1.5 L per 100 km. I also force low boost mode when engine is cold.

There is this strange thing about GU 4, where I have better economy in the city than on the open road and I have heard from the others the same thing. (GU4 owners)

It works with needle closed as well so I have very aggressive spool up and handy low to mid range torque doing it this way.

Regards
Sounds like I should have at least one switch to disable high boost--fairly simple to do and worthwhile just to see any difference. I will keep data flowing as I get stuff completed.
Cheers to all