Water level indicator

[leman_opc]

I'm currently planning an install of hfs3 system on my Opel Astra OPC (=Astra VXR in Vauxhall range), and the best place for tank/pump we found is behind the front bumper.

With the tank installed there I'll be not able to see the water level (visually, so to say), so to have an idea when to fill the tank I need a water level sensor.

My question is - from the manual I'm unsure how the supplied water level sensor works. Does the sensor activate the failsafe immediately when the low water level is detected or there is a kind of intermediate state (water is low as indicated with a blinking yellow led on the gauge but the system still working yet with no failsafe on)?

Also, would be great to know the logics behind the water level sensor operation in hfs3 (the sensor itself appears to be a discrete output one so I would imagine hfs3 controller should have a kind of algorithm to filter out the low water level signals due to simple water movements back and forth on cornering etc.)...

[leman_opc]

Just gave a careful read to the installation guide, it says that normally failsafe on OE solenoid should be wired as white wire to ECU and brown wire to solenoid (when the OE ECU to solenoid wire is spliced).

Just before that the manual says that brown wire is normally opened link to white, and black is normally closed. So I imagine normally (when the hfs3 is on and no failsafe is triggered) the solenoid should have its pulse from ECU, so it's white wire to ECU and black to solenoid. When the failsafe is on or the whole hfs3 is off then it's no voltage to solenoid and the boost is limited to wastegate actuator breakdown pressure.

So if the black wire is normally closed it looks like the black wire should be connected to solenoid. But the manual says brown...

Lost a bit now - would really appreciate your help Richard on this...

[leman_opc]

One last question ))) I think I saw a recommendation that the pump in line should be on one level or below the tank out, but now I can't find where I saw this...

Is this really a prerequisite for normal operation (i.e. no air in the line) or may I simply make a draw fom the bottom of the tank and locate a pump on top of the tank?

The reason for asking is that "a pump below the tank out" requirement will result in pump being fitted behind the front bumper 10cm from ground - I will obviously make some kind or dirt/water protection there but I imagine it will still be not good. If it's possible to locate the pump on top of the tank, then I may locate the tank behind the front bumper and the pump in the engine compartment (much safer / cleaner place).

[Richard L]

Originally Posted by leman_opc

I'm currently planning an install of hfs3 system on my Opel Astra OPC (=Astra VXR in Vauxhall range), and the best place for tank/pump we found is behind the front bumper.

With the tank installed there I'll be not able to see the water level (visually, so to say), so to have an idea when to fill the tank I need a water level sensor.

My question is - from the manual I'm unsure how the supplied water level sensor works. Does the sensor activate the failsafe immediately when the low water level is detected or there is a kind of intermediate state (water is low as indicated with a blinking yellow led on the gauge but the system still working yet with no failsafe on)?

Also, would be great to know the logics behind the water level sensor operation in hfs3 (the sensor itself appears to be a discrete output one so I would imagine hfs3 controller should have a kind of algorithm to filter out the low water level signals due to simple water movements back and forth on cornering etc.)...

You are correct about the level sensor, it is not just on/off.

The system monitors the duty cycle of the sensor during the low level period. The gauge led will flash in sync with the sensor's arm but will not shut the system off until the duty is over 50% for a continuous period of 20 seconds.

This algorithm will allow early warning but more cutting off the system.

If water level is low at start up, the system will not turn on, just illuminates the "low level" led on the gauge. The system can only be reset by filling up the tank.

[Richard L]

Originally Posted by leman_opc

One last question ))) I think I saw a recommendation that the pump in line should be on one level or below the tank out, but now I can't find where I saw this...

Is this really a prerequisite for normal operation (i.e. no air in the line) or may I simply make a draw fom the bottom of the tank and locate a pump on top of the tank?

The reason for asking is that "a pump below the tank out" requirement will result in pump being fitted behind the front bumper 10cm from ground - I will obviously make some kind or dirt/water protection there but I imagine it will still be not good. If it's possible to locate the pump on top of the tank, then I may locate the tank behind the front bumper and the pump in the engine compartment (much safer / cleaner place).

The pump can normally prime itself few feet about the water level. But if you allow the water level to run so low that sucking in air is imminent, the system will not recover as quickly compared to a gravity fed setup.

If you are install the pump and relay in the engine bay area, make sure the water cannot trickle along the harness and work itself in to the relay and pump. Make a downward loop along the pump harness to avoid trickling water.

You must insulate the cable gland at the back of the pump with some silicon sealant. Plastic bag up the relay cluster is possible.

[Richard L]

Originally Posted by leman_opc

Just gave a careful read to the installation guide, it says that normally failsafe on OE solenoid should be wired as white wire to ECU and brown wire to solenoid (when the OE ECU to solenoid wire is spliced).

Just before that the manual says that brown wire is normally opened link to white, and black is normally closed. So I imagine normally (when the hfs3 is on and no failsafe is triggered) the solenoid should have its pulse from ECU, so it's white wire to ECU and black to solenoid. When the failsafe is on or the whole hfs3 is off then it's no voltage to solenoid and the boost is limited to wastegate actuator breakdown pressure.

So if the black wire is normally closed it looks like the black wire should be connected to solenoid. But the manual says brown...

Lost a bit now - would really appreciate your help Richard on this...

As soon as you turn the system on, the relay is energised. This invert the "normally opened" to "normally closed" orientations. We did this because if power is interrupted at any point, the system will automatically cut boost. This is a "power fail" failsafe.

This diagram will help you:

[leman_opc]

Thanks for your detailed response Richard!

You mentioned that the pump may prime itself few feet above the water level, but the risk of air sucking is higher. I that a serious risk or maybe it could be somewhat cured by fitting the low level sensor a bit higher above the water draw point?

Asking because my setup options are limited to the tank installation behind the front bumper (red box in the pic below) and pump installation either on top of the tank in the engine bay (relatively dry area) or behind the front bumper on the other side (green boxes in the pic below). The latter pump position will allow almost horizontal feed from the tank draw point but there is no water / dust protection behind the bumper, I may arrange something to cover from direct water splashes but it will be still hardly safe place from the dust etc. Do you think the setup with the pump on top would be a livable solution in my case?

VXR_front_edit.JPG

Also I would appreciate your opinion on the nozzle placement. I've already decided in favor of single-nozzle setup with nozzle location after the IC but before the throttle body, so my options are basically before the MAP/IAT sensor or after it. I read here on the forums that you had experience with WMI setup on Astra Coupe with basically the same engine as mine and in that case there was a problem with nozzle spraying on the MAP/IAT. I didn't see any pics of that setup though, so I'm unaware whether it was a case of nozzle set directly opposite the MAP/IAT sensor or it was before the sensor but the W/M mixture did not evaporate well before reaching the MAP/IAT sensor. On the other hand injecting before MAP/IAT looks still good since IAT will register lower itake temps and have the ign angle set more wisely instaed of blindly running more advance implying that the WMI is on and working.

So I would highly appreciate you advice whether you think the W/M would evaporate well and not cause MAP/IAT going bad when the nozzle is placed before the sensor (red circle in the lower part of the intake), alternative placement (after the MAP/IAT) is a red circle in the upper part of the intake. MAP/IAT sensor placement is the green circle on the pic below.

Eng_top_edit.JPG

Thanks in advance for your advice!

[Richard L]

As long as you don't go more than 12", air will not affect the priming (4mm ID hose). It all depends on how much vacuum the pump can generate (dry condition) to lift a given mass of water up a given height. As you know, the pump is designed to pump water and not air.

I don't think you have anything to worry about on your install setup.

As far as your concern regarding spray water/meth at the MAP/IAT sensor, I suggest you ignore them and put your nozzle as far away from the throttle as possible, preferably at the exit of the IC. This will give you best charge air cooling and even cylinder distribution.

The MAP/IAT sensor is going to going be smothered the moment you snap the throttle shut. When the fast moving air hit the throttle plate, it is not going to stop but bounce around. The inlet pipe will experience a mini gale storm 10 within.

[leman_opc]

It's always good to have the developer knowing the kit A to Z supporting the community )))

On the 1st point - did I understand it correctly that even in case of air stack 12" height in 4mm ID tube the pump is capable (though not specifically designed for) to create sufficient vacuum when working in dry condition to ensure the acceptable priming?

[Richard L]

Yes, it does.

This is based on the the mass of water inside a 4mm ID tube. I did a calculation some time ago, you need 4" of vacuum to lift 12" of water vertically.