Dawes and needle valve clarification please.

[Ben81C]

Hi all, been a while since i have posted lots going on in the world, but back to the important stuff, i have fitted a catch can and am currently wondering if i fit a manual boost controller (which i am about to do anyway), does this remove the need for a Dawes and needle valve, or is this still required to provide a mechanical fail safe to prevent over boosting? Its a 2003 3lt turbo diesel. Thanks patrolers.
Ben

[Rusty86]

The Dawes and Needle valve set up is the manual boost control which takes the control away from the ECU. You use these to set the max boost (dawes) and then control the turbo spool up rate (needle), so you will set these up as the fail safe to stop any overboosting problems. Blocking the EGR is also advisable to stop the recirculation of exhaust back through the engine which causes problems.

Probably the best place to look is these pages from Chaz's website. http://www.chaz.yellowfoot.org/zd30_engine_problems.htm and http://www.chaz.yellowfoot.org/Manual%20Boost%20Controller.htm It explains the need and reason for doing the NADS mods, and then detail on how to install and set the Dawes and needle.

Hope that helps,

Rusty

[Ben81C]

Thanks Rusty i think i misread the link you sent the first 10 times i read it. I missed the placement of the needle valve i.e in dash. Which confused the hell out of me. Pays to read carefully before posting an apparently silly question.

[megatexture]

Better off posting a silly question then doing something wrong and costing $ or doing irreversible damage to your rig!
if your anything like me its bloody late when you researching stuff and have to read things twice as your seeing double.:icon_bonk:

[Rusty86]

The Needle valve can either be installed in dash if you have 2 boost settings or which to change spool up according to conditions on the fly, or installed under the bonnet at a set setting.

Yes as megatexture says better of asking just to be sure, there's sometimes so much info that it gets mighty confusing!

Cheers

[mudski]

I saw this kit listed but it doesn't have the dawes valve. 1St. Would this kit be good to buy? 2Nd. Whers a good place to get the dawes valve? As the same one in the link provided by Rusty86.

http://www.crosscountry4x4.com.au/products.php?productid=274

[boots]

Dawes valve purchase from www.3barracing.com very good mob to deal with .

[mudski]

Er sorry mate. Check out the link I stupidly forgot to put in in my OP. Am I correct saying that in that kit that is the needle valve? As what I would prefer to do when I set my car rig up is have the boost controller in the dash just like what is in the link Rusty has posted.
So the things i need to buy is :
Boost and EGT gauges
Catch can
EGR blanking plate
Dawes and needle valve
and about ten years to fit it...:trink13:

[Rusty86]

The Cross Country kit contains Dawes, catch can and egr blanking plate, no needle. I had enquired and they had had problems with a few client's trucks with setting the spool up rate with the needle valve, so they leave it out and didn't recommend it. They set the Dawes as purely a boost limiter to like 16psi or abouts and leave it at that.

I had initially looked at getting this kit but you can do it for cheaper and better quality buying individual items from different places.

- Dawes from 3barracing as boots mentions approx. $40 shipped to Aus
- Needle from Dependable Distributors in Adelaide $85
- egr blanking plate from Ferret here on the forum $30
- Provent 200 catch can form Western Filters on Ebay for $170 plus another approx $50 for hoses and fittings etc, or whole kit for $300.

I've read that the Cross Country catch is no where near as effective as the Provent which is by all accounts the only way to go. There were reports of the CC catch not catching everything as supposed to. I'm only going on what I've read on this one as I don't have either catch cans, but hearing this about the CC one switched me off the kit and I'll be getting a Provent 200.


Yes, the list of items to get is correct. Search for people's install threads for guidance, there's heaps out there on this forum.

I'm not sure if its advisable running just the Needle valve, you can have this in dash to adjust the turbo spool up rate but the Dawes valve is the one which will control the max boost and with tweaking of the 2, you'll set the required boost at various rpm as mentioned in Chaz's document.

Don't worry, it took me a few months to get boost and egt gauges and almost a year since I've owned the car to finish the other mods (all going well this will be done in the next couple of weeks). I'd definitely get the gauges installed to begin with so you can monitor levels and actually see what's happening, then go about the others mods. Dawes, Needle and egr block should be done together as you shouldn't need to mess around with the vnt screw on the turbo which you would need to adjust if you did the egr block by itself (which may cause overboosting problems).

Hope this helps,

Cheers,
Rusty

[Ben81C]

I have spoken to a few trusted mates some of whom are mechanics including the diesel specialist i use (who said they used to fit Dawes and needle valve but not any more) and some are just car nuts, they all say the same thing, and that is that they cannot work out how the Dawes valve could stop over boosting, they all say over boost is caused almost exclusively by the waste gate failing or as was explained to me today by the bloke i ordered my boost and EGT gauges from that u can think of overboost as a shop with a front and a rear door, say you can only have 6 people in at once (say 6psi) with standard boost control, as the 7th person (or 7psi) enters the shop, at this point the door at back (ie wastegate opens) and the first person (or psi) exits the rear and only 6 remain inside. However there can be a delay from when the signal to open the rear door (wastegate) and when this actually happens (ie open wastegate) and this is where the problem begins as 7,8,9 and so on can be forcing there way through the front door as the rear door is trying to open, they cant get out before more come in and presto over boost.
Every single person i have asked has said no you need to install an electronic boost controller as they actually take proper control of the waste gate by monitoring and controlling boost and take into account the pressure building via exhaust? What is the go?
Also i showed the people i asked the install diagram from this site and they all scratched their head in confusion as to how the Dawes valve really does much at all with regard to over boost? I am now confused as every one here says there great but i cant find any body else who will fit one or even knows what their purpose is, i am seriously thinking of going for the electronic boost control over the Dawes valve.

[Ben81C]

All other advice from here i have taken with catch can already fitted, boost and EGT gauges (autometer) ordered today and as an extra i am having a turbo timer fitted in 2 weeks. EGR block after i decide on my method of boost control. What to do what to do??????

[Rusty86]

I'm no expert and usually go on the advice of those in the know like Chaz and a few others. The links on Chaz's site probably explain things the best and easiest to understand.

I'll leave it to others to explain why the Dawes and Needle set up is the best way to go. It's definitely achieved great results for people that install it
Cheers,
Rusty

[mudski]

I'm no expert on this as I'm still learning but I thought the dawes was to control the spool up rate of the turbo ( making it spin up faster or slower) and the needle valve is there to control the boost.
From what i have read and understand this is how the setup works. If it doesn't work the way it should I'm sure there would be hundreds of users from here, and other 4by forums scratching thier heads. If I have time I'll pop into JPC in Thomastown and ask Mark their. If anyone knows this bloke will. He does this shit for a living.
OT, I was talking to the chaps at 4x4 Solutions yesty and he said if you want to 4by to wheelstand go see JPC. If you want your 4by to go a bit better and have better fuel economy, go see Ray at Turbo Engineering....

[Rusty86]

Other way around, Needle controls turbo spool up rate and with Dawes you set max boost pressure

[mudski]

Yer thats what i meant... :p

[Chaz]

I have spoken to a few trusted mates some of whom are mechanics including the diesel specialist i use (who said they used to fit Dawes and needle valve but not any more) and some are just car nuts, they all say the same thing, and that is that they cannot work out how the Dawes valve could stop over boosting, they all say over boost is caused almost exclusively by the waste gate failing or as was explained to me today by the bloke i ordered my boost and EGT gauges from that u can think of overboost as a shop with a front and a rear door, say you can only have 6 people in at once (say 6psi) with standard boost control, as the 7th person (or 7psi) enters the shop, at this point the door at back (ie wastegate opens) and the first person (or psi) exits the rear and only 6 remain inside. However there can be a delay from when the signal to open the rear door (wastegate) and when this actually happens (ie open wastegate) and this is where the problem begins as 7,8,9 and so on can be forcing there way through the front door as the rear door is trying to open, they cant get out before more come in and presto over boost.
Every single person i have asked has said no you need to install an electronic boost controller as they actually take proper control of the waste gate by monitoring and controlling boost and take into account the pressure building via exhaust? What is the go?
Also i showed the people i asked the install diagram from this site and they all scratched their head in confusion as to how the Dawes valve really does much at all with regard to over boost? I am now confused as every one here says there great but i cant find any body else who will fit one or even knows what their purpose is, i am seriously thinking of going for the electronic boost control over the Dawes valve.
Ben81C,

It sounds like none of your mechanic mates or diesel specialist are familiar with the VNT controlled turbochargers used in almost all late model diesel cars. Variable nozzle turbochargers don’t use or have a wastegate and unlike a conventional wastegated turbocharger, they’re controlled by vacuum rather than pressure. Controlling boost with a wastegate is easy and in that case I would agree that an electronic controller is the better option, but in our case, and the ZD30 Patrols VNT unit, this doesn’t apply.

The main reason we fit a Dawes TDi controller is to enable bypassing the ECU control solenoid after blocking the EGR. The Dawes valve does control boost well and many people use them with good results. It’s just something fairly new that not too many diesel mechanics may be familiar with unless they frequent the Patrol or VW forums. Initially the TDi valves were produced for TDi VW Golf and Jeda cars in the USA, but they are also ideal for the ZD30 Patrol with its VNT turbocharger.

[boots]

Hi Chaz . your second sentence ,bottom paragraph should read like this mate . The dawes valve does control boost EXCEPTIONALLY well and many people use them with FANTASTIC and AWESOME results . JMO . Thankyou for sharing your knowledge once again .

[Chaz]

Hi Chaz . your second sentence ,bottom paragraph should read like this mate . The dawes valve does control boost EXCEPTIONALLY well and many people use them with FANTASTIC and AWESOME results . JMO . Thankyou for sharing your knowledge once again .

Thanks mate, just being modest.
I've also come across a few that don't recomend them because they're not familiar with the Dawes valve. Initially we were looking at fitting a convenional wastgate turbo off a Navara to overcome the issues, but that would mean an exhaust dump change as well, so the cheaper option was the TDi Dawes valve which gives much the same results while retaining the original turbo and exhaust.
Cheers,

[mudski]

Sweet, Got my Provent from Ebay, needle valve from Dependable, dawes is ordered from 3bar, blue LED dash globes from Ebay and the boost/egt gauge from Mc.Nally's. Just gotta wait for the last two to get here now. O.h and the EGR plate is ordered too :D

[Ben81C]

Ben81C,

It sounds like none of your mechanic mates or diesel specialist are familiar with the VNT controlled turbochargers used in almost all late model diesel cars. Variable nozzle turbochargers don’t use or have a wastegate and unlike a conventional wastegated turbocharger, they’re controlled by vacuum rather than pressure. Controlling boost with a wastegate is easy and in that case I would agree that an electronic controller is the better option, but in our case, and the ZD30 Patrols VNT unit, this doesn’t apply.

The main reason we fit a Dawes TDi controller is to enable bypassing the ECU control solenoid after blocking the EGR. The Dawes valve does control boost well and many people use them with good results. It’s just something fairly new that not too many diesel mechanics may be familiar with unless they frequent the Patrol or VW forums. Initially the TDi valves were produced for TDi VW Golf and Jeda cars in the USA, but they are also ideal for the ZD30 Patrol with its VNT turbocharger.

Ah that is the missing info from the set up and explain diagram everybody has missed and why every one has been scratching their heads, this has cleared the air well and truly. Its easy to make decisions when you have the whole story and have a clear idea of how things work. Great explanation and thank you for filling in the blanks Chaz. I will get one ordered ASAP. Thank you all.

[Ben81C]

Thanks all for the advice i have just ordered Dawes kit from 3bar in the us and the needle kit from dependable in Adelaide. I am picking up Boost and EGR gauges (autometer) after work tomorrow and its booked in to have these and a turbo timer fitted next Wednesday. hopefully a mate who know gets the concept has time next weekend to help me fit the Dawes and needle. Catch can already fitted. and the EGR block will be fitted same time as Dawes and needle. Ye ha nads for Goldie hornebag.
Thanks again Patrollers!!!!!
Ben

[robbo71]

Sweet, Got my Provent from Ebay, needle valve from Dependable, dawes is ordered from 3bar, blue LED dash globes from Ebay and the boost/egt gauge from Mc.Nally's. Just gotta wait for the last two to get here now. O.h and the EGR plate is ordered too :D

That's my exact set up and after much research is the bees knees. I went one further and got a pillar pod off Ebay so I can fit a water and gearbox temp gauge (mines an auto so always careful not to overheat).