Vacuum Question

[LoserbabyS13]

I am wondering what the vacuum lines are for that run right next to the igniter into what looks like a boost solenoid? Is this needed. Also I just finished my swap and have it running and I followed the wiring instructions from Heavy throttle but there were a lot of un-used wires up in front of the battery tray is this normal? I will post pics in a new thread.

[NeedCAforS13]

search for boost solenoid... but short answer: no you don't hook up the boost solenoid

and yes there are alot of un-used plugs and wires going to the ECU...

Sean

[datsunboy]

I'm using that boost solenoid to control boost

[NeedCAforS13]

thats a first... I've never seen one around here still using that. Both SR's and CA's have them, but most people eliminate it. thanks for the correction:)

does it make a difference?

Sean

[datsunboy]

my diagrams show that the only thing it controls is the fuel pressure regulator....just to give a higher pressure on start-up....but thats only for ease of starting....ANDthat solenoid looks AND operates EXACTLY the same as the solenoid provided with the "Link" boost control system ( my mate bought a Datsun 120Y with a CA in it.....and the previous owner had paid $297NZ just for the solenoid.....so don't chuck it out! )

I'm still looking for a adjustable pressure switch that will allow me to adjust the boost eg....switch doesn't operate untitll it sees XXpsi, where it then switches...and puts power into the solenoid.hook the solenoid up between the waste gate and the compressor, and block one port........so that when solenoid is off......air from the compressor can't get through ( therefore increasing boost )...then when the pressure switch goes....the solenoid then lets the air go back to the wastgate.

I think ( havn't tried it yet )....that this may cause a little flutter at max boost.....but that depends on the quality of the switch and solenoid I guess.

Any ideas?

[biosehnsucht]

In other words you're wanting a poor mans electronic boost controller?

[gore]

and there is something wrong with that?!:D

[Jezz_s13]

Some people in the uk have used the solenoid to be able to turn their BOV on and off.

But otherwise ditch it and run a pipe straight from the plenum to the FPR.

[biosehnsucht]

You could build a shall we say MEBC (manual electronic..) with a voltage comparator (I'm sure there's some sort that when a > b can output a signal), a variable resistor (pot), and a few supporting bits (voltage regulator and the like), basicly use pot to adjust the voltage level (boost) you want to have trigger the wastegate, and of course a MAP sensor outputs linear voltage with regard to absolute pressure so if it was 5 bar absolute and you wanted to cut off at 1 bar boost (2 bar absolute) you'd set your pot to 2 volts... and of course the output of the comparator goes to the solenoid (possibly via a transistor to raise the power level up to 12V from 5V or whatever else the rest of the circuit runs on)

[boost_boy]

Ditch the boost solenoid, unplg the hose from the wastegate and have fun :bash (Feel the power; blow the engine). At least it's a quick high:D

Dee

[datsunboy]

lol....TRUE that!whats wrong with having something for almost free instead of paying hundreds?

yeah...talked to a mate that knows lots of electronics.....he said he'd make me up system using comparitors and a a pot to adj it....therefore being a electronic boost control

the Zed cars came with a electronic oil pressure gauge on the dash...so I've grabbed a sender off one...that sends out a different voltage depending on pressure