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Discussion Starter #1
I am getting ready to install a new boost controller in my car. I had a look last night at the existing one and also the standard solenoid pipework.

My guestion is on the existing one, there was a fuel pressure reference pipe, a boost pressure pipe that tapped into the actuator reference pipes and then another that went round to the inlet plenum side of the engine and appeared to go into the engine under the plenum.

Looking at the standard solenoid, this pipework simply seemed to have two hoses, one out the front and one out the side that also went under the inlet manifold.

what are these doing? I assume measuring the MAP pressure?

puzzled and not sure what to do with these tubes when I fit the new greddy profec controller?

any advice would be really appreciated
thanks
Martin
 

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So your existing solenoid is still connected?

Your best bet is to follow the instructions on the profec and bin off everything else. I mounted my solenoid on the turbo side of the engine bay to make pipework easier.

Not sure how much help that is, lol
 

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Ooh - the inspection blokey didnt plug your standard solenoid back in when he did the inspection did he? This might have caused your boost problems!
 

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Discussion Starter #4
no I dont think he did. I dont understand what the solenoid does? it seems to have both its pipes going under the inlet manifold.

before my boost controler was installed, would one of these gone to the actuator ref tubes?

I dont actually understand what the solonoid is there for? I would assume the actuator springs are set for 0.7 bar boost and the solonoid doesnt appear to be connected to the actuators so what is it doing?
 

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Actuators are 0.5bar.

I never quite worked out how the std solenoid worked, or why it doesnt work plugging an aftermarket one in the same way.
 

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The vac diagram is on page 23 of the workshop manual - but I still cant work out how the hell the std solenoid works :nervous:
 

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It acts like a variable bleed.

The plenum has a spigot under the rear left hand corner. This goes, via a length of rubber pipe, to one of the small metal pipes under the plenum. One end of this pipe is connected to the wastegates, the other to the solenoid.

The second small metal pipe under the plenum connects the other port of the solenoid to the low pressure intake pipe.

So the system works by bleeding some of the boost pressure away from the wastegate and into the low pressure side.

Most / all after market boost controllers work by applying a proportion of boost to the back of the wastegate (its duty cycle). They do not bleed some of the pressure signal back into the low pressure side. Thats why you can`t just substitute for the std solenoid.
 

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Discussion Starter #8
I had the read that several times but in the end I think I got it. a mixture of it being complex and me being slightly drunk I guess.

Can you tell me, what is the low pressure side / intake pipe?

also, the boost controller I have takes a ref from the fuel pressure reg, another line to the actuator and then a third to these pipes under the plenum. I assume this is going back into the low pressure side?

cheers for this info. If I fit a greddy profec controller, I assume I can block off this low pressure line or will this need to be reconnected to the actuato ref line? I assume this is where it was originally. I will ahve to have a look in the morning.
 

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The reading off the FPR will be for the boost reading, so it knows what boost it is actually producing. On the Profec, this is just for the display - the unit doesnt actually aim for a boost level, it aims for a % duty cycle.
 

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Discussion Starter #10
yes, this surprised me actually. Makes it a bit of a pain to set.

Jeff, do you have the standard solenoid plumbed in with your greddy set up or the pipes just plugged up?

also, where did you run the vac line and wires through the bulk head

and finally, where did you taqke your ignition live from?

I am poop with electrics and dont have a test meter which could make it painful finding a ignition live

cheers
mart
 

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*** lighter for switched live. vac lines into the inner arch by the battery and back through along the wing then there's an obvious hole to go through. I binned the standard solenoid and plugged up the hoses.

The Profec isnt very sophisticated, but does its job. You just have to adjust it a little if its particularly hot or cold as the boost level changes accordingly.
 
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