Pav Posted November 11, 2022 Report Share Posted November 11, 2022 Hi All, I'm after some much needed help. I had my car mapped but we couldn't get past 1.6 bar due to 'boost creep', we discovered that the WG (Precision PW66) only had a single blue spring fitted so wasn't strong enough to keep it closed. I opened the WG and fitted another 2 springs red and natural colours, according to the PW66 pdf these 3 springs equate to 1.14 bar, but since doing so I've seemed to have created another problem. Now i have very little or no boost at all! I've removed the WG numerous times to check everything is in order, there are no leaks, diaphragm is good, when applying pressure with airline WG will start to open at 20psi and fully open at 27psi. Boost source is from nipple on turbo housing, new 3 port mac solenoid and all piping is brand new. Is it possible the WG needs replacing, as mentioned it was working fine until i upgraded the springs, unless the turbo isn't producing enough pressure to open the WG? Log file is attached, any help would be appreciated. Many thanks Pav PC Datalog - 2022-10-20 8;56;19 pm.zip Quote Link to comment Share on other sites More sharing options...
Brad Burnett Posted November 11, 2022 Report Share Posted November 11, 2022 Is the fire ring/valve seat for the WG valve in place between the WG and the manifold? That is the main reason I can come up with for had boost now you dont. And adding springs will not fix a creep issue. That is an issue caused by too small of a gate or poor wastegate priority. Id bet on priority as you have a 66mm gate. Quote Link to comment Share on other sites More sharing options...
Pav Posted November 11, 2022 Author Report Share Posted November 11, 2022 Hi Brad, Yes the valve seat is correctly seated between WG and manifold, and the clamp is also seated in position. Excuse my lack of knowledge, i'm ok mechanically but not to clued on with software side of things. When you mention wastegate priority is that a mapping thing? Quote Link to comment Share on other sites More sharing options...
k4nnon Posted November 11, 2022 Report Share Posted November 11, 2022 Hey just to add to this issue, You could have a turbo issue. Your wastegate side of things could be fine but if the turbo is seized or broken somehow you wont get boost. I would check the turbo and make sure everything is good there. A proper boost test is priority, but you may get a sealed system and still have a problem with the turbo, so if you can get the inlet off make sure you can spin it freely by hand and that the shaft play is in spec. Make sure your vacuum lines to the boost controller are correct and recheck. Even without the tuning side of things you should be able to build some type of boost. You have a mechanical issue right now so that needs fixed first.. Best of luck figuring it out. Quote Link to comment Share on other sites More sharing options...
Pav Posted November 11, 2022 Author Report Share Posted November 11, 2022 Hi k4nnon, Thanks or your reply, turbo is definitely good my inlet is exposed but has a turbo guard so i can easily check the shaft play. I've also done a boost check with air compressor hooked up to the turbo inlet and all is good. As mentioned, the only thing i did was open the WG to add more springs, i'm now thinking the combination of springs i have added is too much and the car isn't able to produce enough pressure to overcome the spring pressure, therefore i might need to reduce the spring combo. What do you think? Quote Link to comment Share on other sites More sharing options...
Adamw Posted November 11, 2022 Report Share Posted November 11, 2022 What do you mean by "Now i have very little or no boost at all!"? Does that mean your boost runs away to the moon and cant be reduced, or the boost is too low and cant be increased? Is the wastegate and solenoid plumbed like below? Quote Link to comment Share on other sites More sharing options...
Pav Posted November 11, 2022 Author Report Share Posted November 11, 2022 Hi Adam Yes WG and solenoid are plumbed as per your diagram. Everything was working fine on the dyno run but would not push beyond 1.6 bar as the wastegate would not remain closed. I upgraded the springs and since then I have very low boost, almost as if it’s a NA engine. is it possible that my spring combo is too much for the turbo pressure to open the WG? Quote Link to comment Share on other sites More sharing options...
Adamw Posted November 11, 2022 Report Share Posted November 11, 2022 If the springs were too heavy and the wastegate wasnt opening the boost would rocket off to the moon until the boost cut caught it. If you have no/low boost then you have a large leak - either on the boost side of the engine somewhere between turbo and manifold, or the wastgate popet. If you pull the exit pipe off the watsegate you will hear if it is leaking through that. Quote Link to comment Share on other sites More sharing options...
Pav Posted November 12, 2022 Author Report Share Posted November 12, 2022 Hi Adam, I've got no/low boost, definitely not hitting any boost cut/limit! I will do another boost leak check capping in from the turbo inlet, when you refer to the WG exit pipe, is that where my screamer pipe is? Quote Link to comment Share on other sites More sharing options...
Adamw Posted November 12, 2022 Report Share Posted November 12, 2022 32 minutes ago, Pav said: WG exit pipe, is that where my screamer pipe is? Yes. Pav 1 Quote Link to comment Share on other sites More sharing options...
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