My current setup for controlling boost is with a greddy profec II but would like to switch over to an ecu boost control. I am already aware of the GM and Tactrix solenoids but would like to use Greddy’s solenoid. Has anyone done this? Is this doable? Is there any difference setting this up compared to the GM install?

Dudical26's How to Install HFS-5 meth kit under the Appendix 1 – Fail Safe Options referred to using a MAC solenoid, very similar to the Greddy’s, and soldering inline a 3 watt 10 ohm resister. This is where my idea came about.

Appendix 1- Fail Safe Options:

There are many different way to hook up a failsafe to the multiple failsafe triggers on the HFS-5. I will describe a couple of the most common setups.

If you are using factory boost control or a GM solenoid to control boost (as I am) you can set up you system in the following way. You splice simply cut one of the wires going to the boost control solenoid, then you connect each end of this cut wire to the new wires you ran to the DDS3 junction box specifically for Failsafe control. You then connect the wires to Map Switch 1 & 2 or pins 11 & 12 on the junction box.

Optional: I wanted to be able to run high boost even if my HFS-5 was turned off. The way I have my failsafe set-up, it cuts boost if the system is not turned on or if there is a failure. I wired in a bypass switch that would allow me to run high boost even with the system turned off. This can be dangerous because if you forget to turn the switch off you are in effect making your failsafe useless. The bypass switch simples connects the wires leading to pins 11 & 12 on the junction box. When you flip the switch it connects the wires and allows the boost solenoid to turn on without the DDS3 powered up.

For a manual boost controller you can setup the solenoid in the following way. Once again the bypass switch can be used in the same manor.

The failsafe solenoid that many people use is a MAC valve, here is some info about it.
http://www.macvalves.com/Catalogs/NT/36.pdf
http://www.macvalves.com/PDFS/36_Series.pdf
where to buy: http://www.macvalves.com/distributors/USA.htm
Part #:36A-AAA-JDBA-1BA

Here is a picture of my MAC solenoid with a Weather-Pak Connector on it.
If you replace your stock boost solenoid with this you will need to install a 3 watt 10 Ohm resistor in line with the solenoid.

 

I am not familiar with the greddy solenoid but if it functions like the MAC or GM solenoid then it will work just fine.

You can measure the resistance across the solenoid to see how far it is from stock then you will know what kind of resistor you will need to add.

I think the stock resistance is 35ohm, so if your solenoid is 25ohm, then you just need a 10ohm resistor with 3 or more watts.

Also, hook up power to the greddy solenoid to test how it operates so that you know how to connect the boost hose.

 

ok, so i measured the ohms for the stock and showed 33.9 while the greddy measured 37.1. Does this mean I dont need a resistor?