Dave's flex fuel module arrived this weekend and I couldn't wait to wire her up to work with the Alky control kit.
The results were amazing, I have it setup where if the pump achieves pressure (green light on Alky control kit) the module pulls to ground and tell the PCM 100% Alcohol is entering the system. At which point you can add timing only when you're spraying methanol, as well as you can lean out your fuel system as soon as meth hits in the Stoich table.
Here is what it took to make this work.
You need a DPDT (double pole double throw) relay where one throw is normally closed, while the other is normally open. Reason being is the pressure switch on the pump pulls to ground when there is no pressure, and once pressure is achieved, it actually opens the circuit. When circuit is open (alky control kit not pulled to ground) that means there is pressure and the light on the alky goes green.
We want the opposite to happen for the flex fuel module, we want to pull to ground once pressure is achieved instead of the opposite.
By using a DPDT relay that has 6 pins (one throw normally open, one throw normally closed) using the following:
-Red wire going to meth pump goes to relay for constant power with key on
-One wire will go from relay to one end of pressure switch on meth pump
-Wire from other end of pressure switch on meth pump will go to ground
(above is done so depending on what pressure switch does, it pulls the relay on and off)
-Two ends on relay will go to direct ground (tie into wire from pressure switch thats always grounded, bottom wire on pump)
-One end on relay goes to alky control kit wire thats normally goes into one end of pressure switch
-Last end on relay goes to flex fuel module.
The above is the basics, once you look at a DPDT one throw normally open, one closed relay you'll see how its done, simple.
The idea is that once you are key on, the relay is energized because the pump with no pressure pulls to ground. The throw that opens the circuit in this condition (key on no pressure) goes to the flex fuel module, the idea is that when there is no pressure, we create an open to the flex fuel module so it does not activate. When this is happening, we want to keep the concept the same for the alky control kit, so no pressure means it pulls alky to ground.
Once pressure is achieved in the pump, the pressure switch opens, this de-energizes the DPDT relay, creating an open to the alky control kit which gives you the green light as intended, but actually pulls the flex fuel module to ground.
I'll post a video on you tube later tomorrow perhaps how it works.
It's really neat, because you are now much safer running meth to add power this way. If the pump fails during a run, your light on alky will go red and the flex fuel module will tell the PCM no alcohol, so you revert back to regular timing and fueling.
Best part is you still maintain the functionality of your test button on the alky kit, if you press it, you will see the car bog while cruising and your A/F will dip indicating the nozzle is not clogged because the flex fuel module will only add timing in PE mode for those who use it for what I want.
You can tune meth by spraying on the IAT, but its not always the best way, I've noticed that once you spray the IAT it reacts real fast to colder temp, but even if meth stops flowing, it takes a while for the IAT to go up in temp, mainly because the IAT is still wet. The other drawback of of tuning for power using IAT is in Canada, you'd need a winter tune, because when I spray in the summer, the IAT temps go down to the same temps as no meth in the winter, so the tune is off.
Using Dave's flex module and using the pressure switch to add / remove timing or fueling if you like, is the safest by far.
Sorry for the long thread but this toy is really cool!! I'll post a vid later.