NITROUS OXIDE ( nos / n2o ) advice forum

Just sorting out my wiring routes and plans, question.

I am using a pressure switch to cut the Nitrous once the turbo is up to speed.

Whats the best way to wire it ?

I was thinking of placing a 30Amp relay between the arming switch and the pulsoilds. And using the pressure sensor to open the relay and cut the injection.

Sound right ?

That'll do it but you'll be able to use a lower Amp relay and it'll last longer if you put it in the trigger circuit rather than the arming circuit (this is if you are using either a TPS or a progressive).

Regards

Yes i am using a TPS, which i hope is in the post as we speak

Along with a bottle Bracket and a T piece.

That being the case could i do away with the relay and just put the switch series with the tigger wire ? The red wire out of the TPS and onto Pin 86 ?

Unfortunately yes the TPS needs a relay as it won't deal with the current the solenoids need.

Which means that you can use the pressure switch in the same relay circuit as the TPS, then you wont need 2 relays just one 20+ Amp unit.

Regards

So i could earth the relay through the pressure switch, so when the switch opens it breaks the earth.

And opens the relay ??

Yep

I am learning slowly,

Next question, can you supply an adjustable 'normally-closed' pressure switch ?

Yes we do

Where are you going to mount the pressure switch?

Next to my pressure switch that the water injection uses, and T off the hose.

That's the boost tube to the wastegate then?

Nope, you need to measure the pressure in the inlet manifold, so its a pressure tapping into the inlet manifold.

Used for pressure switches, MAP sensor, etc

What I'm getting at, is it a standard pressure tapping on the 400 or one you've had to add?

The Rover Turbo engines have 3 pressure take offs on the back of the inlet manifold.

Trev,

I am trying to work out why you have supplied me a 'normally open' pressure switch.

As far as i can understand, i need to break the earth above 12psi - therefore i require a 'normally closed' switch.

I have a TPS, which i assume causes the pink wire to earth when it hits the 'set' voltage. Thereby closing the relay and earthing the pulsoilds.

Where and how in the wiring should i put this 'normally open' switch