Who thought NC, NO, and COM were clear abbreviations?

The simple 'Merican explanation is Not connected, No, and common. None of which stand for those.

To help the future single turbo generation, let me break it down.

COM goes to the wastegate, not common manifold pressure. Think of it more like wastegate COMmunication.

NC means Normally Closed. Which means nothing to those who are first time wastegate installers. It's so confusing I'll explain the other shorthand first

NO means Normally Open.

Those two, NO and NC, are used one or the other. One of those two will plug into boost pressure before the butterfly valves.

You can't damage your rx7 if you mix them up. I know. Your car will build boost SLIGHTLY above the wastegate spring if pressure is plugged into the wrong one of the two.

Damn apexi wastegate solenoid wasted a lot of my time with poor English instructions and confusing acronyms.

 

You got it all wrong!..(Following is purely in fun)
NO: is Normally Oriental!.
NC: is Normally Canadian!.
COM: Come On!!..'Merican!
...
normally open,normally closed,common.
abbreviations all used for electrical wiring.

 

A lil too much coffee this morning? What if you have an enteral wasteg gate??? Then the routing is different, back to the drawing board...

 

lol so confusing. It was late night caffeine. And pent up frustration from misinformation.

For the apexi external wastegate that comes with the AVCr or the power fc boost controller kit, the boost pressure has to go into NC - normally closed.

Correct me if I'm wrong on this explanation, but first of all who determined what is "Normally" lol. To me, normal on my rx7 is under boost. I believe they mean at idle.

At idle the wastegate COM line is not getting boost pressure and consequently would make the wastegate rely on the spring pressure.

Once you apply almost full throttle, the wastegate COM line is then given some pressure. I'm assuming if my spring is rated for 15psi, the COM line needs the equivalent of 10 psi to get the total desired boost of 25.

Is that correct or am I just lucky that it works at all?

 

NO, NC, and COM are simply solenoid/relay terms. On a solenoid NC is the port that is blocked when the coil is not energized. Has no bearing on when your car in normally under boost lol.

 

So, i got lucky haha, Even after owning it for 10 years, i should not be allowed to own a FD that hits 25 PSI... lol thanks.

 

"Once you apply almost full throttle, the wastegate COM line is then given some pressure. I'm assuming if my spring is rated for 15psi, the COM line needs the equivalent of 10 psi to get the total desired boost of 25. "

Yep think thats basically the idea, unless your building too much back pressure at higher rpms, it might push the gate open no matter what you do. Your sig say you have a 35r. It most likey won't carry 25psi to 8000rpm and beyond, Too much back pressure. Your really at the end of that turbos turbine, time to upgrade IMO.

Try running a stiffer spring, it should be a little more stable, but again lots of back pressure at that boost level.

 

That totally makes sense. Thanks for the clarification.

It's my first foray into > 15 psi with my gt35r so 24-25 will keep me happy for some time. I run perturbo WI so I imagine that has a positive effect on the compressor map. I run stock ports still. So that probably has a negative effect on it all.