help with plumbing up boost/ vacuum system

[Tensa Zangetsu]

Hey guys, sorry to make a new topic, but im having trouble understanding where to source the correct line for the boost and vacuum gauge, voodoo box and bov?
Iv got the Flyin Miata voodoo turbo kit for my 99 nb, and in the installation manual it says to plumb the bov to the front of the intake manifold and the voodoo box and gauges from the back, but then iv read where people say to flip them around, what's the best option?

[NitroDann]

The back of the manifold is the most stable, and in fact you can plumb everything from there.

I also suggest you plumb the wastegate actuator from the inlet manifold assuming you have a way to tune this car otherwise you will get weird shaped boost curves and spikes.

Dann

[Tensa Zangetsu]

Sweet thanks, also what about the turbo outlet, it has a hose connection on it, do i connect that to the wastegate aswell or block it off?

[MrRevhead]

If you plan on controlling boost:

[NitroDann]

I would connect everything to the inlet manifold preferably using the back ports for the wastegate ecu and gauge while using the front ports for bov and less important things.

I would then block the compressor nipple.

The reason to run everything including the wastegate from the manifold is that after the hot air has passed the intercooler it has cooled and shrunk and so 7psi at the outlet of the turbo may be 5posi by the time it hits the throttle, so you want the 7psi wastegate controlled from the throttle, which is where you want the 7psi.

Who cares what the pressure outletting from the turbo is, when you can use the actual pressure going into the engine as a source.

Dann

[Tensa Zangetsu]

Thanks for clearing that up, it makes a lot more sense now

[vrmmmpshhh]

you'll get a much better boost curve if you get the pressure source from right up next to the throttle body. my pressure source comes from the inlet manifold.

[Tensa Zangetsu]

If i connect a gauge to the turbo thats set at 6psi, and a gauge at the throttle manifold, and find that theres a 1-2psi drop, would i then up the spring in the wastegate 1-2psi higher so that the turbo produces 7-8psi to compensate for the 1-2psi drop so that i can get the desired 6psi into the engine?

[NitroDann]

Here read this. Its not just temperature its restriction also.

http://www.miataturbo.net/diy-turbo-dis ... ebc-47532/

After you have read it you will realise that Ive suggested point c, it also works fine however the throttle is likely to not quite as linear.

Dann

[Tensa Zangetsu]

Hey guys, sorry for bringing this thread back up but i didnt want to start a new one and i couldnt find a solution. I was driving and while under boost i heard the BOV flutter, but i didnt lift off the throttle, i thought i burst a vacuum line, so i pulled over and checked all the lines but nothing. My AFR is reading 9.8 when normal is 14.5, my vacuum is reading 10 when normal is 20, i changed spark plugs but hasnt fixed my problem, please help!

[NitroDann]

So you definately didnt blow a hose?

Anywhere?

Dann

[Tensa Zangetsu]

Im pretty certain i havnt, but im going to go through and run it all again, ill post back if it helps or not

[Tensa Zangetsu]

Nope, still having idling problems

[Tensa Zangetsu]

It turns out it was my MAF, i unplugged it and bang the engine went back to normal, except its still running rich, is there a way i can get it back to normal?

[NitroDann]

Do you have an oiled air filter?

Im guessing that the MAF is dirty or buggered, unplugging it puts the car in limp home mode, so it will ignore the MAFs faulty signal.

Dann