Originally Posted by
Wilburnator
I know this topic has probably been done to death, so I apologise for bringing it up again. However I just would like an answer to a couple of questions regarding boost controller/Dawes valve install. The car in question is a 2008 CRD ZD30 (stock aside from a provent 200, current max boost is around 14psi and very erratic at low rpm)
Do you have to install a needle valve, as well as the boost controller? No. You don't have to run either really. Installing the Dawes at the least, will limit the maximum boost and reduce fluctuations
What are the advantages of using the needle valve? (Is it just to do with a more linear boost curve?)Using a needle valve lets you control how fast the turbo will spool up from idle to maximum boost. Many people say its not needed for the CRD. Well they are right, to an extent. The car will drive fine without it. But it will drive a lot better with it. I have met a few people that are just running a Dawes or a Tillix, and have said that it goes better but still is a bit laggy down low. I fitted up a needle valve and gave it a quick road tune and the turbo response time is a lot faster there for reducing the lag feel.
Another way of looking at it is, we all spend coin modding our 4wd's to make them that little bit better with every mod. So. The question needs to be. Why wouldn't you install a needle valve?
To run a Dawes/needle system, does the EGR need to be blocked? Or can I leave it and simply install the Dawes/needle valves? No. But in my opinion is still a good idea to do so. Albeit, illegal.
Thanks heaps in advance! 👍
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