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Need help on LINK G4+, Supercharger activation logic

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Hello friends

I have posted this question on LINK's support forum but unfortunately there was no solution to my problem. Maybe someone here can work the riddle out?

ECU: LINK Extreme g4+ PlugIn ECU

Vehicle: Nissan 350Z, Supercharger with electromagnetic clutch

The supercharger's clutch is actuated above a certain rpm or a certain throttle pos. The arming is done via a DI (toggle switch).

The above is already set up and dialled in but here comes the tricky part:

---> For safety purposes, the arming switch should be disregarded (if in OFF position and switched to ON) by the ECU if the rpm is above 5000 rpm

Thanks for scratching your heads about this one.


I'm not familiar with the Link software, but let's assume your supercharger output is Output1. Hopefully your ECU has another spare configurable output pin available, let's call it Output2. Configure Output2 to be active and send a switched ground when Engine Speed is below 5000 RPM. Then wire the arm switch so it gets grounded by Output2 (rather than a simple connection to chassis ground when the switch is on). Now the arm switch is sending a signal that will be active when the switch is on and the RPM is below 5000.

Hope that helps,


Hi Scott

Thank you for your comment. Your suggestion sound good. Now I need to wrap around my head how to actually configuring it in G4+ ;-)

Let's back this up for a second and see if we can get to the simplest solution for your final result. Why do you need an arming switch when you already have speed/load based control in the ECU? Is this set by some kind of racing regulation? Does the ECU signal disable the clutch or enable it? i.e., the clutch is normally engaged (making boost) and the ECU turns it off based on speed and load? Or the clutch is normally disengaged (not making boost) and it's only enabled under certain conditions?

Hi Raymond

The arming switch serves the purpose of driving purely NA sometimes, customer requirement.

The ECU activates the clutch if:

- arming switch is in ON pos. and:

- rpm > 1800


- TPS > 25%

Since this car is a demo vehicle for supercharger conversions, it is going to be driven by many different kind people on racetracks and on the road. The idea is to prevent the SC to kick in suddenly if the arm switch is "accidentially" switched to ON above around 5000 rpm because this could easily result in sudden loss of traction, especially in a curve and / or in wet surface conditions.

Looking forward to your comments.

Ok how about this. Use a locking button. Push the button IN, (all the way down), and the supercharger is DISARMED. Since the button is already down, the driver can't accidentally push it down again. You're not going to bump it if it's already down. When the button is up, the supercharger is ARMED. That way if they bump it, they can only disarm it. Also, locate it on the dash away from where people normally put their hands and arms.

I'm trying to keep it simple.

If you use a virtual aux you should be able to do it.

The virtual aux is your "failsafe"

Aux output (clucth) = off




Virtual aux ON

Then you set the aux output (clutch) to include


Virtual aux = OFF

I think I misunderstood your original question, my suggestion above will simply prevent the switch from ever being active above 5000 RPM. I agree it might be good to try a different type of switch. A 'safety switch' like this one needs to be twisted & pulled to re-arm, similar to what you might find on machine shop tools.


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