[dan-0]

Hey guys
(Look at my signature for a list of the mods I have done)

I took my car to a local 4wd dyno workshop. They said they were unable to do a complete dyno run because my car would lose boost after 5 seconds.

They have never seen a dawes or needle valve before (and they call them selfs affiliates of ARB) and told me I have to sort out the plumbing before my Troll can do a run.

He drew a picture to explain what my car was doing:

After taking my $120 I drove home wondering what I had spent it on AND I hope the forum guys can help me out.

I have taken a few pics of my setup. Can anyone offer some advice.

• My car never goes above 300c EGTs
• Dawes set at max 14psi
• 8psi @ 100km/h on a straight (5th gear)
• spikes to 14psi going uphill then cuts into limp mode if the hill is steep enough
• Economy is great - 10.5L/100kms with 33's

 

[SHANE 3.0]

Dan-O

Should'nt be going to limp mode, jump into my Pics and there may be something that can help out, the green and White Damper valve may be on the wrong hose, again should not be limp mode.

 

[geeyoutoo]

How long has the setup been on? Everthing looks OK, the damper looks OK. You may be just spooling up too quickly when you stand on it, what happens if you open the needle valve further until the max boost just starts to drop off?

 

[heyhey]

Mine kept going into limp mode if I drove that little bit too hard, so I pissed the kit off.

 

[jamfox]

thats what my set up looks like, although ive turned my VNT grub screw in 1/4 turn, Dawes set to 15psi. have no issues and mine spikes to 18psi when i gas it. never overboosted

 

[geeyoutoo]

Dan-O, Mate if you get the chance try moving the needle valve into the cab, it's an easy mod and the benefit is you can play while your driving and instantly see the reaction, again a simple mod.

If you look in my Dawes album you will see where many of us place it, there is already a hole there, just needs opening a bit and also you need to purchase a couple of 1/8th BSPF 90 degree adapters to screw into your needle valve body so the connections the hoses push onto are easily got at.

Highly recommend it.

Different models can react differently, yours is an early one so the ECU shouldn't present too many issues, Luckily I didn't need to make any changes to my VNT screw and my high side dawes is set to 16psi and spikes to 20+ with the needle valve closed and 18 when its open !/2 turn..

 

[dronus4x4]

Can anyone post a pic of this VNT screw that i need to turn in 1/4 turn?

 

[geeyoutoo]

Hi Dronus, was about to take a photo for you then remembered there is a good one in the GU bible on pages 60 and 61, tells you all you need to know.

 

[dronus4x4]

I can see that going horribly, horribly wrong.. Im not getting overboost so ill leave it until i get more courage up.

 

[Chaz]

I can see that going horribly, horribly wrong.. Im not getting overboost so ill leave it until i get more courage up.

Hi Andrew,
Mate, don’t be afraid to give this a go. Just be careful when popping off the “C” clip. I just tie some very thin fishing line to it so that when it shoots off, I’ve got hold of the other end.
Then undo the 2 actuator nuts and remove the actuator. After that it’s easy to get to the locknut and grub screw. I ended up turning mine down ½ a turn to eliminate any spike. Boost comes on a bit smoother, not as aggressive and I can keep the needle valve closed without any limp mode issues.

 

[paul.helm]

OK Chaz, A question if you dont mind,

What would the outcome be if I lengthened or shortened the actuator rod?

I ask this as I have adjusted the dawes to 16PSI & have the needle valve closed, adjusted the VNT grub screw & still get limp mode symptoms or too fast a spool rate. And EGR is blocked.

What would you suggest to further slow the spol rate without opening the needle valve?

 

[dronus4x4]

Deleted

 

[dan-0]

Can anyone post a pic of this VNT screw that i need to turn in 1/4 turn?

Can you please start your own thread next time or use the search function!
Thread hijacking is very annoying.

 

[Chaz]

OK Chaz, A question if you dont mind,

What would the outcome be if I lengthened or shortened the actuator rod?

I ask this as I have adjusted the dawes to 16PSI & have the needle valve closed, adjusted the VNT grub screw & still get limp mode symptoms or too fast a spool rate. And EGR is blocked.

What would you suggest to further slow the spol rate without opening the needle valve?

Hi Paul,
The answer is simple….. set the Dawes to 15psi.
You can adjust the limiting screw up to a full turn, but I wouldn’t go further than that. Remember that these turbo’s are setup on a flow bench by Garrett, so chances are that no two are the same in relation to screw setting positions. This becomes more apparent after doing quite a few of these with exactly the same settings and the cars all react slightly differently.
I can’t stress enough, DO NOT mess with the actuator rod length! In particular NEVER shorten it. This can create all sorts of issues. Shortening it will cause the turbo to boost up way too fast and making it longer will give you more turbo lag than you’ll want. It’s best to leave it alone, because as I said, it’s been adjusted on a flow bench for efficiency.

 

[Chaz]

Dan,
It certainly looks like it’s going into limp mode. Have you checked for a fault code?
If there is no MIL, then chances are that it’s over boosting or a possible MAF issue. Perhaps verify that your boost gauge is accurate also.

Your setup looks ok to me, although it looks like your Dawes valve is adjusted all the way out for maximum boost.

 

[dronus4x4]

Can you please start your own thread next time or use the search function!
Thread hijacking is very annoying.

I think that learning how to adjust the VNT screw might be helpful to the original post down the track, but, ok ill stop posting here, good luck with your original issue, hope you find what you are looking for (hint the answer can be ironically found using the search function also)..

 

[SHANE 3.0]

I think that learning how to adjust the VNT screw might be helpful to the original post down the track, but, ok ill stop posting here, good luck with your original issue, hope you find what you are looking for (hint the answer can be ironically found using the search function also)..

I agree Dronus, same issue so should be able to help each of you with your problems instead of creating further Threads on same issues. If search is used this issue has been around for sometime.
Work together thats what this is all about.

 

[geeyoutoo]

Hi Dan-O,

Shane and Dronus are correct, this is quite possibly where your problem is heading. By moving your needle valve into the cab where you can play with it under load we can artificially soften the spool up rate etc and this may be a pointer as to whether you need to adjust the VNT screw.

You may need to stretch your dawes spring a little (5mm) to get back a bit of adjustment, your fully in and only have 14PSI.

Understand what your saying but we are all in this together.

 

[lg 91]

after reading all these problems people are having with the dawes and needle valve is making me have second thoughts about fitting one

 

[geeyoutoo]

after reading all these problems people are having with the dawes and needle valve is making me have second thoughts about fitting one

Mate, it sounds like a big problem but like anything once you work it out it's fairly easy. Go ahead and do it you won't be sorry and the forum is here to help if there is a problem.