zd 30 dawes and boost controller

Submitted: Sunday, Nov 08, 2009 at 12:06

ThreadID: 73609 Views:6594 Replies:3 FollowUps:2

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bood

Chaz I have a question for you, 1. When you use a single dawes valve is the vacum solenoid completly eliminated? How do you set the dawes valve to get 3 boost settings thru 3 rev ranges. 2. With dual boost stages how are getting 2 boost settings (eg high/low) and what is the maxiumn, is it still 18? Do i need a special boost controller as i only have the normal one. First motor went bang, 60 000km's later second motor went bang, same thing, piston and big end. Just finished rebuild, keen to make sure it lasts this time. Before my boost varied from 15-30psi, now i have blocked the egr and wound back the actuator limit screw half a turn, now have 15psi, it has hit 20psi once, 2nd gear and still have turbo flucuation.

Cheers Bood

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Reply By: Member - Malcolm (Townsville) - Sunday, Nov 08, 2009 at 14:25

Sunday, Nov 08, 2009 at 14:25

bood

I would suggest you post your question for Chaz on the patrol forum.

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AnswerID: 390467

Reply By: Chaz - Monday, Nov 09, 2009 at 23:03

Monday, Nov 09, 2009 at 23:03

Thanks Malcolm, I don’t get on here as often as I'd like to.

Hi Blood,

If you block your EGR, you should by-pass the vacuum control solenoid. This will eliminate your boost fluctuations as a result of EGR.

The Dawes valve is set to control maximum boost but you should fit a needle valve to help control your low rpm boost or turbo spoolup. Then you can calibrate the turbo’s spooling through the rev ranges with the needle valve and boost limiting screw on the turbocharger. Ideally a setting of no more than 6psi at 1500rpm and 10psi at 2000rpm can be achieved. Above 2000rpm it should be safe to go to a maximum boost setting by the Dawes valve up to around 16psi at 3600rpm. This is ideal, but getting close to it would be good for engine and turbo life as well as lowering EGT’s.

Using a duel stage boost controller means fitting two Dawes valves and an additional solenoid valve to switch between the two stages. It simply gives you the ability to switch between two maximum limits, eg. 10psi for around town with low EGT’s and 15psi on the highway when EGT’s increase. These maximum boost limits are at moderate throttle inputs and can be exceeded at full throttle when rpm gets to maximum of around 4000rpm.

You do need a special controller such as the Dawes valve. It’s similar to a conventional controller, but doesn’t have the bleed hole to let pressure escape in order for the waste gate to close. ZD30 VNT Garrett turbo’s are controlled by vacuum rather than pressure, so a different controller is needed.

Here are a couple of links that may help.

http://www.chaz.yellowfoot.org/zd30_engine_problems.htm

http://www.chaz.yellowfoot.org/Manual%20Boost%20Controller.htm

All the best,
Chaz

AnswerID: 390692

Follow Up By: bood - Monday, Nov 16, 2009 at 23:08

Monday, Nov 16, 2009 at 23:08

Hey Chaz , JOHNO here again got my needle valve today in your diagrame you run one side of needle valve to the i filter resonator, s that that black cylinder thing on the tappet cover, I have run 1/8 hard plastic line to the engine bay just no sure where they go,not sure if all motors have the same stuff. Cheers JOHNO>>>>

FollowupID: 659343

Reply By: Outbacktourer - Tuesday, Nov 10, 2009 at 10:22

Tuesday, Nov 10, 2009 at 10:22

Just a comment, those standard boost levels you are seeing seem way high to me. I have an unmodified version (although I do have Dtronic) and see 5-7 at cruise and no more than 18-20 with foot to the floor.

OT

AnswerID: 390727