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Those boost and EGTs figures are fine. 10psi cruise @ 100kph is what some strive for to provide good ECO. I do have some concern with the Dawes being wound in so far.
With the Dawes wound in just about all the way, makes me think that the ball is not seating correctly and there maybe has a small leak past the ball at seat. If it is leaking there would be +ve air pressure from cooler entering the vac line at very early/low boost and the VNT vanes may not stay closed enough early for the turbo to spool up fast enough.
Could be the seat or spring lets see.
Could remove the Dawes, connect a small length of vac hose to each end of the Dawes and apply compressed air supply with a regulator fitted to simulate it being connected to the cooler boost take off. Using the regulator on the air supply, slowly increase the pressure from zero to the pressure where you feel slight air passing through the Dawes and this will give you an indication of boost level set of the Dawes.
Let me know result.
U can put the outlet piece of hose near your face and feel the passing air starting to pass through.
Your vacsol is blocked off correctly and as said: the electric connector needs to be plugged in.
Really think u can sort this out without giving money to a tuner.
@mudski does the Brass body Dawes have a seat insert for the ball to nest against?
Thanks for all the help Bidja. Unfortunately I don't have any compressed air.
Per @mudski advice: With your Dawes, should have a seat insert_not sure if machined into body (brass) or a fitted type seat. Check and let us know?
Yeah the Dawes has like a tapered seat for the ball.
With the needle valve adjustment, 12 psi would be a good cruise target boost. IMO_For now, until we get Dawes/Boost sorted I would close needle completely and run max spool to remove a variable.
With needle closed go for a drive, check cruise and max boost with the Dawes set as now and then unwind Dawes one turn at a time and see how max boost changes.
Can check Dawes target boost with a bike pump with gauge but no big deal.
Well. I wound the needle almost all the way in, left a 1/4 turn out, boost was great, I was getting 23 PSI at 90 kmh in 4th without trying.
Pulled over, undid the Dawes 2 turns. That made it terrible. Screwed it back in 1 turn, still terrible, wouldn't boost over 10PSI. Stopped again, turned off motor, unplugged battery in case the thing had gone into limp.
Wound the needle right the way in and noticed that the actuator rod bounced up & down off the screw.
Set the needle valve so the rod is just touching the screw and fiddled with the Dawes a bit more and I think I've got it to as good as it will get.
Now getting 11psi at 100kmh with EGTs on the 200s in todays weather.
I'm happy with that, the vehicle drives nicely enough.
The only thing I'm unsure about is that the Dawes is pretty much screwed completely in. There's still some room left for adjustment, but not alot.
It does boost higher than 11psi, its sits on 11 at 100kmh on the flat with cruise control on. When I come across a hill with cruise on, it'll boost up to 14 to maintain speed.
Maybe I could borrow that Tillix of yours Bidja and see what happens?
It does boost higher than 11psi, its sits on 11 at 100kmh on the flat with cruise control on. When I come across a hill with cruise on, it'll boost up to 14 to maintain speed.
Maybe I could borrow that Tillix of yours Bidja and see what happens?
What I think is happening is:
Dawes spring has become worn and has a reduced spring rate which allows the ball to bounce on/off its seat even at very low boost pressure (ie at idle). Maybe this why you see the actuator arm rise/drop rapidly at idle with the needle closed because the Dawes ball is bouncing on/off its seat causing sudden fluctuations of +ve air (boost) pressure from cooler side into vacuum hose (downstream of Dawes). This rapidly changes vacuum to actuator causing the rod up/down movement especially at max turbo vane closure (needle closed).
Also with Dawes screwed nearly right in the spring maybe compressed to a solid height forcing the ball very hard up against seat not allowing any boost / +ve air to pass thru Dawes to vary the vacuum to actuator. Hence allowing full vacuum to actuator (nom 24”Hg) causing max vane closure and this produces the max boost from turbo (say 24psi), but as you open the needle this reduces vacuum to actuator and opens the turbo vanes slightly causing boost to reduce.
This is what you are currently doing along with opening Dawes slightly.
Could try stretching the spring but any improvement may not last long.
Yes I can send you my spare Tillix boost controller and see how goes. PM me you address.
Will also send a Tillix needle valve as this can be installed down stream of the boost controller (Dawes or Tillix)_use two needle valves. In your case, would set the Tillix to 10psi and adjust the downstream needle to a target max boost of say 16psi and you retain your current needle valve for spool adjustment. Called Boost controller plus two needle valves. This is for later.
Pulled the dawes apart again today. Measured the spring, 18.75mm. Stretched it to about 24mm.
Put it back together. Wound in the needle valve right in, the actuator no longer bounces off the stop screw. Set the rod to just sit on the stop screw and wound out the dawes, about the thickness of the lock nut. Test drive gave me nice linear boost up to 16psi while accelerating up to 100kmh. Took up the same stretch of road and am now getting 14-15 psi at 100kmh with cruise on, up from 11psi.
Boost is peaking at around 16-17 psi which is where it should be if I understand correctly.
EGTs are under control, high 200s low 300s.
Going to keep an eye on it and chase up some springs to keep in the spare parts bag.
It does boost higher than 11psi, its sits on 11 at 100kmh on the flat with cruise control on. When I come across a hill with cruise on, it'll boost up to 14 to maintain speed.
Maybe I could borrow that Tillix of yours Bidja and see what happens?
Hmm. Remove the IC and see if there is any oil deposits on the bottom side. If there is, you’ll have a boost leak, which it seems to me you are experiencing.
Just read your last post. You must have one of the first revisions of the Dawes if you had to stretch the spring.
But, still check the IC for oil deposits in my opinion. Stock IC’s are known to spring a leak.
Originally Posted by Bidja
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