EGTS Up Why?

[10G]

Well went through and cleaned electrical connections, replaced some vac hoses and disassembled and cleaned the Dawes valve.

Nothing made a difference until I cleaned the Dawes valve.

I marked the Dawes valve before disassembly, but when I put it back together I put it back to where I reckon it was, but it's now boosting it's brains out. I keep blowing pipes off. I'm getting up to 22psi at about 1/3 throttle on the flat.

When I put the Dawes back together, I put the ball in the small half and the spring in the large half which I'm pretty sure is correct.

I'm winding the two halves apart to lower the boost. Is that correct???

I can't remember the procedure for setting the boost. From memory it's something like go up a hill (or put the vehicle under load) at about 3000 rpm until you get a boost of 15-16 psi. Is that correct??

Thanks for any help.

[Bidja]

Well went through and cleaned electrical connections, replaced some vac hoses and disassembled and cleaned the Dawes valve.

Nothing made a difference until I cleaned the Dawes valve.

I marked the Dawes valve before disassembly, but when I put it back together I put it back to where I reckon it was, but it's now boosting it's brains out. I keep blowing pipes off. I'm getting up to 22psi at about 1/3 throttle on the flat.

When I put the Dawes back together, I put the ball in the small half and the spring in the large half which I'm pretty sure is correct.

I'm winding the two halves apart to lower the boost. Is that correct???

I can't remember the procedure for setting the boost. From memory it's something like go up a hill (or put the vehicle under load) at about 3000 rpm until you get a boost of 15-16 psi. Is that correct??

Thanks for any help.

@10G Good news, u having success _ But appears that Dawes is assembled incorrectly as u describe.

Dawes assy:
Drop ball in large body end first, followed by the spring. Large body section goes nearest to cooler.

Wind the male threaded "smaller section" in (clockwise) to increase boost.

I can't remember the procedure for setting the boost. From memory it's something like go up a hill (or put the vehicle under load) at about 3000 rpm until you get a boost of 15-16 psi. Is that correct??

In 3rd gear, hauling @ 3000rpm (with needle closed) and when no limp (approx 15-16 psi) open needle valve so lever is just resting against stop screw or spool rate that suits _ do not make it laggy. May need to wind Dawes in a little if boost drops when u adjust needle valve.

Suggest that you remove all boost hoses and wipe off any excess oil residue, clean mating parts and re clamp.

Get it working and I can then suggest an alternate arrangement that may improve drivability _ if interested.

[10G]

Well that's all resolved.

Nothing changed until I disassembled the Dawes valve, cleaned it re-assembled the correct way.

EGTs are back to where I'm used to seeing them, which is helping the coolant temp to drop a bit. Boost is back up to 14-17 psi, spiking at 20-22. Power is back, it's actually pulling pretty well, it accelerates from 100 in 5th which is good.

Took it up a hill in 3rd at 3000rpm and boost was around 15-17psi.

Feels all free and happy once more. :-)

Thanks everyone for the help.

Now what's that alternate arrangement you mentioned Bidja???

[Bidja]

"10G firstly great that all working well.

There are 2 other VNT boost control method u can try. Give it a couple of week, leave Dawes and needle valve as configured for now just to make sure all keeps performing well.

Wil post alternate boost control methods in a couple of days as am a bit flat out with shed build at the moment.

[10G]

"10G firstly great that all working well.

There are 2 other VNT boost control method u can try. Give it a couple of week, leave Dawes and needle valve as configured for now just to make sure all keeps performing well.

Wil post alternate boost control methods in a couple of days as am a bit flat out with shed build at the moment.

Yep, no problem.

Drove to work up hills etc today. Running like a dream, couldn't get rid of the smile.

[10G]

Just when you think you've got it solved.

I've noticed my boost creeping back down again in the space of 1 week.

The Dawes is just about screwed right in.

When I pulled the Dawes apart last week, the only thing that I could see wrong was that there was a reasonable amount of oil in there. I didn't stretch the spring, just cleaned and re-assembled.

I'm still using the original hose clamps that Nissan use on the turbo pipes, would it worth using better ones? If so, what type?

The vacuum hose I'm using is 6mm, but it's softish. Could that be being sucked closed? I noticed it's way softer than the original vacuum hose.

Can anyone remember how to set the needle valve? I can't remember the procedure. I didn't do this the other weekend.

Thanks fort any help.

[Bidja]

@10G my comments in RED

Just when you think you've got it solved.

I've noticed my boost creeping back down again in the space of 1 week.

The Dawes is just about screwed right in.Pull Dawes apart again, check for contaminants, clean it with cotton wool bud_ reassemble it and try it out first

When I pulled the Dawes apart last week, the only thing that I could see wrong was that there was a reasonable amount of oil in there. I didn't stretch the spring, just cleaned and re-assembled.Leave spring as is, what Dawes do u have "Brass coloured body" or "Black 3BarRacing"?

I'm still using the original hose clamps that Nissan use on the turbo pipes, would it worth using better ones? If so, what type?If clamps tighten securely they should be fine. Check for splits/cracks etc in hoses and make sure they fit tight (clean away oil residue.

The vacuum hose I'm using is 6mm, but it's softish. Could that be being sucked closed? I noticed it's way softer than the original vacuum hose. I prefer 3mm ID hose and secure with small cable ties

Can anyone remember how to set the needle valve? I can't remember the procedure. I didn't do this the other weekend.

As I have said last week _ In 3rd gear, hauling @ 3000rpm (with needle closed) and when no limp (approx 15-16 psi) open needle valve so lever is just resting against stop screw or spool rate that suits _ do not make it laggy. May need to wind Dawes in a little if boost drops when u adjust needle valve.

Suggest that you remove all boost hoses and wipe off any excess oil residue, clean mating parts and re clamp.

Thanks fort any help.

[10G]

Thanks Bidja.

I have a brass Dawes.

My needle valve is under the bonnet, so I can't adjust while driving at 3000 rpm.

When we setup these valves initially, I can remember adjusting the needle valve so it's just sitting on the stop screw, I guess that was done at idle or is that what I should do with idle set at 3000 as you mention?????

[Bidja]

Thanks Bidja.

I have a brass Dawes.

My needle valve is under the bonnet, so I can't adjust while driving at 3000 rpm.

When we setup these valves initially, I can remember adjusting the needle valve so it's just sitting on the stop screw, I guess that was done at idle or is that what I should do with idle set at 3000 as you mention?????

haha_Yes adjust needle with eng at idle / stationary. Tell U, I would not be hanging out of the drivers side window, hauling in 3rd gear @ 3000rpm, with bonnet up trying to get a visual of the actuator lever resting against the vane limit stop screw.

Darren Dawes had a replacement spring for the early Brass Dawes boost controller. Send him an email and he may send you one for elimination purposes (explain the boost situation briefly) _ info@3BarRacing.com

Clean the Dawes you have and see how she performs after a clean. CRD can run happily at max spool, so u can shut needle right off.

I have a Tillix boost controller here and needle valve that I could loan to you to see how boost behaves.

Do you still have vac solenoid under the bonnet and plugged in to elec harness keeping ECM happy when using manual boost control?

I currently run VNT vac solenoid with the ECM, in conjunction with a Dawes (3barracing) and needle valve for boost limiting. Can try a couple of other things but give your current setup a go again first for info.

[BillsGU]

Usually higher EGT's can be boiled down to two main issues. Less air than normal (air leak or turbo problems) or more fuel than normal (injector pump or injector problems).

I would start by looking at air leaks and if none can be found - a good tune up may fix or at least find the problem.