2008 STi Port Injection

[BakZamGai]

Hi folks

Was one of the original part of the HFS-6 GB when it was first launched. The serial number of my unit is 090008. Been meaning to fit this system when I have completed my engine build, but my curiosity has gotten the better of me and I have begun installing my HFS-6 on my STi.

Modifications on the car.
1. 73mm KS-Tech air-intake
2. APS Front Mount Intercooler
3. Reversed Intake Manifold
4. Custom 2.5" aluminum intercooler pipes
5. APS Tumbler Valve Deletes - secondary injector ports modified for port injection
6. Stock 560cc injectors
7. Uprated Fuel Rails / Regulator with AN-6 fuel lines.

HFS-6 installation details
1. 1 gallon Jaz tank
2. AN-3 lines from Aquatec pump to FCM
3. AN-3 lines from FCM to 6 port manifold (1 port blanked, 5 ports with 4mm compression fitting)
4. 4 x 0.4mm nozzles into each cylinder using nylon lines
5. 1 x 0.4mm nozzle 8" before throttle body, 2" behind Bypass valve using nylon line

The 0.4mm nozzles were recommended by Richard from our previous conversations for my final engine build which would put out about 400whp. But since I am installing the system before the final engine build, which restrictor should I be using on the FCM if I am intending to run either water or 50/50 methanol/water mix?
The car is currently untuned, and I want to be able to setup the HFS-6 so that I can get it tuned all at once.
I'll put up pictures of the completed install once the tune is completed.

Thanks all for your help!

Cheers
Dennis

[Richard L]

Hi folks

Was one of the original part of the HFS-6 GB when it was first launched. The serial number of my unit is 090008. Been meaning to fit this system when I have completed my engine build, but my curiosity has gotten the better of me and I have begun installing my HFS-6 on my STi.

Modifications on the car.
1. 73mm KS-Tech air-intake
2. APS Front Mount Intercooler
3. Reversed Intake Manifold
4. Custom 2.5" aluminum intercooler pipes
5. APS Tumbler Valve Deletes - secondary injector ports modified for port injection
6. Stock 560cc injectors
7. Uprated Fuel Rails / Regulator with AN-6 fuel lines.

HFS-6 installation details
1. 1 gallon Jaz tank
2. AN-3 lines from Aquatec pump to FCM
3. AN-3 lines from FCM to 6 port manifold (1 port blanked, 5 ports with 4mm compression fitting)
4. 4 x 0.4mm nozzles into each cylinder using nylon lines
5. 1 x 0.4mm nozzle 8" before throttle body, 2" behind Bypass valve using nylon line

The 0.4mm nozzles were recommended by Richard from our previous conversations for my final engine build which would put out about 400whp. But since I am installing the system before the final engine build, which restrictor should I be using on the FCM if I am intending to run either water or 50/50 methanol/water mix?
The car is currently untuned, and I want to be able to setup the HFS-6 so that I can get it tuned all at once.
I'll put up pictures of the completed install once the tune is completed.

Thanks all for your help!

Cheers
Dennis

This is some late install, more than a year old since the GB. It is better late than never.

4x 4mm jet in manifold and 1x 0.4mm before throttle. can the jet be further away from the throttle? With the FMIC, you can place the 0.4mm at the exit of the IC to allow better intercooling when the air and water is mixed earlier.

You will also need a check valve after the split between the 4-port manifold and the single jet. This arragement is to prevent water communtating between the engine vacuum (4 port) and the FMIC jet (non-vacuum).

Richard

[BakZamGai]

Hi Richard

Big change of plans on my side. The kit was originally purchased for install on a 2007 STi which subsequently got sold and replaced with a 2008 STi which this kit is going on right now.

For the placement of the pre-throttle jet, how much distance is required? I'm trying to avoid putting it infront of the bypass valve to prevent water ingestion on the intake.
As for the check valve, that has been included in my purchase. Given that I am using your new and shiny 6 port manifold, do I put the check valve closer to the manifold or the jet?

As for the restrictor on the FCM, which size would be more suitable given my current setup?

Cheers
Dennis

This is some late install, more than a year old since the GB. It is better late than never.

4x 4mm jet in manifold and 1x 0.4mm before throttle. can the jet be further away from the throttle? With the FMIC, you can place the 0.4mm at the exit of the IC to allow better intercooling when the air and water is mixed earlier.

You will also need a check valve after the split between the 4-port manifold and the single jet. This arragement is to prevent water communtating between the engine vacuum (4 port) and the FMIC jet (non-vacuum).

Richard

[Richard L]

The checkvalve should alawya be as close to the jet as possible.

Your pre-throttle shoudl ideally be place at the exit of the IC (FMIC). But you might consider placing it post IC if oyu have a top mount.

I would leave the restrictor out completely on your install if you are using multiple jet. This is becuase there are more twists and turns to impede the water flow.

[BakZamGai]

Hi Richard

Based on the calculation from Jeff's website, the 5 x 0.4mm nozzles are gonna be serious overkill for my setup since i'm running 4 x 560cc injectors, running 18psi and injecting water at the moment.
I get a calculated value of about 370ccs, which is just about the flow for a single 0.7mm nozzle.
BTW, based on the the same calculation, 1000cc injectors and about 25psi gets me 660ccs, which is still too big for the 5 x 0.4mm nozzles.
The big turbo and 1000cc injectors are some way down the road, so what should I do for the moment? Run all 5 x 0.4mm but use some kind of restrictor to keep the flow down? Or seal the port injection for now and use only the post I/C injector?
I've got the following nozzles
0.4mm with 4 scroll insert
0.8mm
0.9mm
1.0mm

Thanks!

Cheers
Dennis

[Richard L]

It took you a while to have the system installed. Over 2 years since you purchsed the HFS-6. Better late then never,. mustn't stop now.

The selection of the jets is not as critical as the HFS-6 can scale the flow up and down electronically.