Subaru STi Port Injection with HFS-6

[BakZamGai]

Hi Richard

I would like your opinion on jet placement if I were to run Port Injection on a Subaru STi.
I am running a APS Tumbler Valve Delete, with provisions for secondary injectors.
As these secondary injector ports are not predrilled, I can have them tapped for the water jets.
Do you think this position is acceptable if I were to run Port Injection?
http://www.airpowersystems.com/wrx/apssti-tdi04/tdi_04.htm
Will the HFS-6 work with this setup? The secondary injector ports are the ones on the top.
I am concerned that the placement of the water jets will be too close to the injectors.

Essentially, the car will run a built 2.5l block with a twin-scroll GT35R with 1000cc injectors.
Also, the intention for the installation of the HFS-6 is to prevent detonation. Would you recommend a 50/50 mix with methanol? Would that provide a greater margin of safety?

Thanks!

Cheers
Dennis

[Richard L]

Hi Richard

I would like your opinion on jet placement if I were to run Port Injection on a Subaru STi.
I am running a APS Tumbler Valve Delete, with provisions for secondary injectors.
As these secondary injector ports are not predrilled, I can have them tapped for the water jets.
Do you think this position is acceptable if I were to run Port Injection?
http://www.airpowersystems.com/wrx/apssti-tdi04/tdi_04.htm
Will the HFS-6 work with this setup? The secondary injector ports are the ones on the top.
I am concerned that the placement of the water jets will be too close to the injectors.

Essentially, the car will run a built 2.5l block with a twin-scroll GT35R with 1000cc injectors.
Also, the intention for the installation of the HFS-6 is to prevent detonation. Would you recommend a 50/50 mix with methanol? Would that provide a greater margin of safety?

Thanks!

Cheers
Dennis

If you are running port injection, it is advisable to put a jet at the exit of ther intercooler (FMIC) or before the TMIC. Put smaller jets (0.4mm) at the ports. 50:50 is an all round performer.

What is the wall thickness on the secondary inject port. The threaded hole for the jet should not thicker than 5mm.

http://www.aquamist.co.uk/forum/jet.gif

[BakZamGai]

Hi Richard

For my setup, the intake manifold is reversed with a FMIC setup to reduce the length of the charge piping.
Any suggestions regarding jet sizing? 0.4mm for Port Injection?
From what you are saying, it looks like a total of 5 jets I will be needing for the setup. 4 for Port Injection and 1 for the exit of the Intercooler.
Will the pump of the HFS-6 keep up with the demand of 5 jets?
From what i recall, the wall thickness is around 4mm or so, I will need to take off the manifold to make some measurements but from your diagram, the optimal position for the jets is going to 5mm so I will add a washer just take make sure that the water jet will be perfectly aligned.
Do you foresee any issues with the water jets positioned just about 1" before the fuel injectors? I have never implemented Port Injection before and especially on a setup that will be running 2 bar of boost. Any issues with water jets being unable to spray due to the boost levels?

Thanks for the help!

Cheers
Dennis

[BakZamGai]

Hi Richard

Any issues with the placement of the waterjets just 1" before the fuel injectors?

Thanks!

Cheers
Dennis
Hi Richard

For my setup, the intake manifold is reversed with a FMIC setup to reduce the length of the charge piping.
Any suggestions regarding jet sizing? 0.4mm for Port Injection?
From what you are saying, it looks like a total of 5 jets I will be needing for the setup. 4 for Port Injection and 1 for the exit of the Intercooler.
Will the pump of the HFS-6 keep up with the demand of 5 jets?
From what i recall, the wall thickness is around 4mm or so, I will need to take off the manifold to make some measurements but from your diagram, the optimal position for the jets is going to 5mm so I will add a washer just take make sure that the water jet will be perfectly aligned.
Do you foresee any issues with the water jets positioned just about 1" before the fuel injectors? I have never implemented Port Injection before and especially on a setup that will be running 2 bar of boost. Any issues with water jets being unable to spray due to the boost levels?

Thanks for the help!

Cheers
Dennis

[Richard L]

Hi Richard

For my setup, the intake manifold is reversed with a FMIC setup to reduce the length of the charge piping.
Any suggestions regarding jet sizing? 0.4mm for Port Injection?
From what you are saying, it looks like a total of 5 jets I will be needing for the setup. 4 for Port Injection and 1 for the exit of the Intercooler.
Will the pump of the HFS-6 keep up with the demand of 5 jets?
From what i recall, the wall thickness is around 4mm or so, I will need to take off the manifold to make some measurements but from your diagram, the optimal position for the jets is going to 5mm so I will add a washer just take make sure that the water jet will be perfectly aligned.
Do you foresee any issues with the water jets positioned just about 1" before the fuel injectors? I have never implemented Port Injection before and especially on a setup that will be running 2 bar of boost. Any issues with water jets being unable to spray due to the boost levels?

Thanks for the help!

Cheers
Dennis

The HFS-5 is scalable so using bigger jet is perfectly OK.

As long a is the water jet is installed beween 3 to 5mm, the spray will be good. If the wall thickness is larger than 4.5mm, you can always put a chamfer in the hole. (you need a chamfer anyway to bed the o-ring on the jet. I suggest get a bunch of Brass jet adaptors so the jet are seated properly.

The pump can support 5x 0.5mm jets easily.