Aquamist HFS4-v3.1 Install, ST165

mickeyfinn · Aug 12, 2020

I'm going to document my Aquamist Water/Meth injection system install on my ST165 Gen1 engine.
Hopefully, for my own reference, and to help to anyone else out.

After seeing some high IAT's, and hearing some knocking, I was steered towards water/meth systems. I wasn't sure I wanted to deal with the hassle of it all, but after hearing how much temps could be lowered, I decided to look into it more.

I looked into systems from Devils Own, AEM, Snow Performance, and Aquamist. It seemed the Aquamist system was a little more expensive, but high quality, with some better failsafe and delivery methods. I also liked the idea of a gauge showing progressively how much injection was taking place, and a lot of people who had the system seemed very happy with it. So I ordered the HFS4 system, and it took about 5 weeks to finally arrive.

I should note. Aquamist later told me that the HFS3 system is probably a better fit for this application, and cheaper.
The HFS4 is geared more towards newer. DI (Direct Injection) cars. I didn't really know this at the time of purchase. Oh well... But, there are some more advanced features on the HFS4 that can be utilized, so all is not lost.

Edit: the HFS4 is more advanced, and uses a complex algorithm that takes into account Injector Duty Cycle and Manifold pressure to deliver the correct spray, and when. There are more failsafe options that can be configured as well.

mickeyfinn · Aug 12, 2020

The system does NOT come with a water tank. Better get that too... and Aquamist had a nice one, so I bought theirs.
I'm going with a 50/50 Water Methanol mixture, which means it needs to be vented outside the car for safety. I added their “Tank remote venting kit” while I was at it.

After receiving all the components, I must say, the quality is top notch! I'm very impressed!

I decided to place the injection nozzle after the Intercooler, but as far from throttle plate as I could. I designed, and made an aluminum weld in bung for the M8 x 0.75 threaded nozzle.
I welded in the bung, then screwed in a “blanking plug” (need to order that from their website too, PN-806-358) So I could drive the car until I got everything installed.

mickeyfinn · Aug 12, 2020

The instructions say to mount the pump below the tank if possible. There isn’t much room in the trunk, and the most obvious place is down in the spare tire well.
I needed the pump as close to the center as possible so the lines going in and out of the pump would clear, and I could get my spare (full size) tire back in. I cut a notch in the mounting plate to allow the best placement.
I used some 10-32 “Nutserts” to anchor the pump to the floor. This made it pretty easy, and I didn’t have to mess around the fuel tank much.

mickeyfinn · Aug 12, 2020

I had to purchase an additional 90 degree fitting ( PN-806-399 1/8 BSP swivelable fitting) to make sure the supply line would clear the spare tire when it was back in it's place. I mounted the Relay nearby, grounded the power to one of the Nutserts, and ran power, and all the lines. I cut some plywood spacers to set the spare tire on top of, to ensure the tire wasn't sitting on top of the lines. I also put everything in some 1/4" Wire Loom for a little added protection.
The Tank Vent is venting there under the car. I routed the supply line under the car (in 1/4" Loom) up to the engine bay. I made sure it was well away from any rotating parts, and exhaust.
I had earlier wired in a distribution fuse block under the seat that was connected to a relay and a 20A Circuit breaker, so it would turn on with the ignition. So I added a 15A fuse and ran the power to the pump.

mickeyfinn · Aug 12, 2020

Again using "Nutserts" I mounted the Tank bracket in place, and finished up the trunk area install.

mickeyfinn · Aug 12, 2020

It's pretty close, but the 5 Litre Aquamist narrow tank does fit. The rear hatchback trunk lid and door closes just fine.

mickeyfinn · Aug 12, 2020

Moving up to the engine bay...
I ran the supply line under the car, and up into the engine bay.
The system uses a Fast Acting Valve (FAV) to: 1. Control the water injection amount. 2. Measure how much is water is flowing, to report this to the Dash Gauge inside the car. 3. Determine if no water is flowing, (clogged nozzle, empty tank) to shut down the system down, and enable fail safe modes.
The instructions say to mount it in a cool dry place close to the Injection Nozzle.
I found a good spot behind the strut housing.
I had some fuel hose laying around, so I ran the Injection Nozzle Line inside it to protect from engine bay heat.

mickeyfinn · Aug 12, 2020

I ran the remainder of the injection tubing up to the windshield wipers. I'll install the nozzle there temporarily, so I can watch the system in action while I am driving around to get things dialed in.

mickeyfinn · Aug 12, 2020

I am running a Link G4+ Standalone ECU.

There is an On/Off button for the Aquamist system on the Dash Gauge. My goal is this:
Aquamist system off = car runs normal, boost pressure is limited to 12psi
Aquamist system ON = boost is increased to 20psi. If Aquamist detects any failsafe (tank empty, clogged nozzle, no flow etc), the Link will know about it, and take action (It has control of the boost solenoid), and can cut fuel, timing etc.

The Aquamist will control how much water injection goes into the engine based on 1. Injector Duty Cycle (IDC) 2. Manifold Pressure (MAP). 3. An algorithm taking into account both IDC and MAP (This is the one we want).

For wiring the power input to the controller (4-Way Power in Connector):
Red: 12V (5A) Switched (IGN SW/pre-crank)
White: Chassis Ground
Black: Chassis Ground
Purple:Head Lamp (+) (For Gauge Dimming)

For wiring the Signals to the grey (RJ48) Connector:
Orange: x
Red: Ignition switched 12V(pre-crank) [Must not appear at accessory key position] ( Connect to "IG2" Wire [Black w/Orange Strip] in the Ignition wire harness under the steering column)
Green: Y-Spliced, No.1 Fuel Injector, (ECU Pin2) [ST185 ECU]
White: Link ECU DI4 (Digital Input #4) XS Expansion Loom
Yellow: x
Black: Chassis Ground, (NOT Sensor Ground), [might introduce noise otherwise]
Blue: MAP Sensor, (PIM, ECU Pin42) [ST185 ECU]
Brown: x

mickeyfinn · Aug 12, 2020

To configure the board properly: We need to change PWM to (-), by soldering a blob of solder on pad location 6:

(This step may not be required for the HFS3 System, but is required if you have the HFS4) I think the DI Systems are based off of (+) PWM, whereas standard Fuel Injectors are based off of (-) discharge.
**The system will flood the engine if this is not correct! So, double check.!**

mickeyfinn · Aug 12, 2020

The Fuel Injectors in my car are Deatschwerks 1000cc Bosch EV14 Injectors, PN- 17U-07-1000-4

(Side Note: Injector Dynamics ID1050x are not compatible with this engine [ST165]. The O-rings are not compatible, and won’t seal. The Injector body length is incompatible, and there is interference between the plug connector and cylinder head).

We need to change the IDC (Injector Duty Cycle) pre-scalar. This allows the system to match the incoming IDC signal for oversized injectors with low duty cycle. to "x1.50"

mickeyfinn · Aug 12, 2020

At the direction from Aquamist:
To get the best atomization of the mist being injected into the engine, we are going to go with a 1.2mm (600cc) nozzle. Turn the pressure up on the pump up by turning the screw on the back 3/4" of a turn.

mickeyfinn · Aug 12, 2020

The most important wires in the system are in the grey (RJ48) Connector, especially the Red wire:

Red: Ignition switched 12V(pre-crank) [Must not appear at accessory key position]
Green: Y-Spliced, No.1 Fuel Injector, (ECU Pin2) [ST185 ECU]
Black: Chassis Ground, (NOT Sensor Ground), [might introduce noise otherwise]
Blue: MAP Sensor, (PIM, ECU Pin42) [ST185 ECU]

Red wire must be connected to the (+) 12V common of the Fuel Injectors.
Looking at the Engine wiring diagram, there are 4 Black w/Orange striped wires that go into the Fuel Injector Resister pack. These wires route to "IGN2" Wire which can be found in the wire harness under the steering column.

I tapped into the Black w/Orange striped wire there. This also fills the criteria of: Ignition switched 12V(pre-crank) [Must not appear at accessory key position]

mickeyfinn · Aug 12, 2020

Reserved

mickeyfinn · Aug 12, 2020

Reserved

underscore · Aug 14, 2020

Nice write up! I had a bung added to my intercooler but never ended up putting the system in, I assume it makes a big difference with the smaller 165 intercooler running that kind of pressure.

mickeyfinn · Aug 14, 2020

Thanks!
Heck Yeah! The whole reason is because of the ST165 Intercooler.
I really underestimated how poor the thing really is.
I don’t really want to bend and fabricate a bunch for a FMIC.
I have an ST205 Intercooler. No way it’s going without a bunch of cutting either.
I figured I’d give this a try.

Which Intercooler did you have that bung welded in?
I had a hard time finding any information on the Aquamist. So I figured I share what I know.
So many people have helped me here.
I hope it’s helpful to someone else.

underscore · Aug 15, 2020

I had it welded into my stock RC WTA intercooler. I went for the same spot as you, as far away from the TB as I could get. Unfortunately the nozzle fouled on the timing belt snorkel and the 90* adapter I needed to make it work is discontinued so I put a plug in the bung and sold the kit.

Gert · Aug 21, 2020

Aquamist, good choice. I have an ERL System 2 kit in my car since 2001. Never had any (serious) malfunction issues.

mickeyfinn · Sep 14, 2020

I've got everything wired up now... going through the pre-start checklist..

According to the manual:
Step 4.
Start the engine and let it idle for a minute or so:
- The green LED on the controller should flicker. The
flicker should speed up with engine speed. If the system
behaves as stated above, you have successfully
wired up the HFS-4!

I'm not seeing this. Somehow the Aquamist controller is not reading the Injector Duty Cycle.

The green wire (in the Aquamist RJ48 grey harness) is for sure connected to Fuel Injector #1 in the Car ECU harness.

I cut the wire, and reconnected them, just to make sure the green wire is indeed tapped into FI #1.
Not sure why it's not working.

I'm at a standstill until I get this resolved. I reached out to Aquamist to see if they have any ideas.

Aquamist HFS4-v3.1 Install, ST165

Member

Member

Attachments

Member

Attachments

Member

Attachments

Member

Attachments

Member

Attachments

Member

Attachments

Member

Member

Member

Attachments

Member

Attachments

Member

Attachments

Member

Attachments

Member

Member

Well-known member

Member

Well-known member

Active member

Member