Anyone tried an FMU based methanol system?

The ideal I am toying with, is using an unregulated shurflo pump, to a 12-1 (adjustable) FMU.

Before the FMU, the water/meth will flow to T connecting to a 20 psi (or preferably adjustable) check valve, the injectors are after the check valve.

Also a 3 way air solenoid between the fmu and manifolds.

Here is how it would work, the pump is activated at 2 PSI, at 4 PSI, the solenoid switches and immediatly throws 48 PSI at the check valve, overcoming the check valve, and passing meth through the injectors (maybe a pair of 500CC injectors).

As boost pressure increases, so does fuel pressure.

This is not intended to replace the haltech controlled cooling mist HSV system I have setup on my Rx7, but is for a different car.

If rpm based control was desired (in this case its really not), than the 3 way solenoid could be PWM'd like a boost controler.)

Any thoughts...

As far as parts source, I have a 12-1 vortec FMU in my garage, that anodised and has a fluorosilicone diaphram, which acording to my quick search should be methanol compatible.

EDIT: in place of the check valve, a simple diaphram valve or solenoid could be used.

Esentially this is just a take on the mechanicly controlled rice racing style system, but using a pump.

 

Ok, I played with this tonight on the porch, also took apart the vortech FMU. The only parts that come in contact with the fuel are a stainless steel (slightly magnetic) disc, an O ring which I replaced with buna from the parts bin and anodized aluminum so it should be safe for the methanol mix.

Also ordered a delrin solenoid valve from mcmaster carr, and a few other parts.

With a ball valve standing in for solenoid valve and a jump box powering the pump, I get 30 PSI at the nozzle with the pump on and no pressure (other than the internal spring pressure) on the FMU. With pressure slowly applied to the FMU via a bicycle pump pressure at the nozzle goes up gradually and consistently. It looks like this is going to work very good.

The application BTW is a small diesel engine, but there is no reason this wouldn't work just fine on an rx7 and be real cheap and reliable setup.

OBX and other china FMU's are available super cheap on ebay. They appear to be clones of the vortech unit, which I believe itself is a clone of a unit made by cartech. These are such simple devices there is no reason that one made in china or ??? wouldn't work just fine. Its quit easy to tune them to an extent also, and adjust the amount of rise with a simple bleed valve (simple manual boost controller), or the kits put out by vortech, rebuild parts are also readily available.

Another added control that isn't necessary in my application would be a pwm 3 way solenoid by (think boost control valve) though this would necessitate a 3D PWM map like the generic pwm maps provided in haltechs and some tuning.

I will post again with pictures when I develop the system further.

 

Got the system installed tonight, but not road tested.

I can't say enough about how good this works, relized I didn't need the on off solenoid. In fact there is no need to even have a seprate switch turn the pump on an off, the pump could be run when the main fuel pump is run from the same circuit and it would work just fine.

In the Jetta TDI (my daily that its installed in), 2 lines run from the engine back to the trunk, one of them caries the fluid forward, I went with a -4 teflon lined SS, (I had 25' of -3 but that turned out to not be thick enough, difference of .4 inches), one line is a vac hose that caries manifol pressure back.

The FMU and pump are mounted on scrap of alum stock, and coupled direcly, the pump is fed by a 5 gallon plastic summit cell, the FMU exit flows out back to the cell like a normal bypass fuel system. Unlike a normal bypass fuel system the injector is 15 ' (of hose) away from the fuel rail, and yet there is minimal to no pulsation at the nozzle visible on a gauge. There is a simple brass T fitting between the FMU input and the pump output which feeds the injection line and a standard hobs switch activating the pump set at 10 PSI. For the connections between pump to FMU, FMU to tank, and pump to tank, I used the blue lined 3/8 fuel injection line and brass barb fittings, and kept these pieces very close together with strait fittings only between them so as to make this the path of least resistance.

Further notes, if anyone decides to copy this get the FMU without a spring, the spring just adds about 4 PSI worth on top of whatever boost the device is seeing, it sets a base pressure of about 44 PSI, having the spring really does turn the device into an FPR, which isn't needed. More on this, the FMU is internaly just like a standard FPR, but with a much larger diaphram permitting at max a 12-1 rise with varios methods of adjustment. Fluid only contacts a stainless shim, a buna O ring and the anodised aluminum body of the device so it should be good with 100% meth providing the anodisation holds up.

This would any kind of pump activation switch because fuid takes the path of least resistance, with the pump on and 0 PSI at the FMU (with the FMU spring removed or with a standard non spring type FMU). There is 0 PSI at the injector nozzle, and infact just a very light drip. All that would be needed to stem the drip would be a cheap .5 PSI or so cracking pressure sprung checkvalve.

I used a home depot style srung ball boost controller, combined with the pressure switch to start injection at 10 PSI boost with 50 PSI of fluid pressure. I have it ramp up to 90 PSI of fluid pressure by the max boost of 20 PSI and its perfectly progressive and easily tunable.

It actually works so well, that I may adapt this system to my Rx7, but with a PWM valve controling boost to FMU (via haltech, allowing for 3 dimentional control), I have been looking to add more capacity than a single cooling mist HSV can support (which works very well BTW), and with no type of valve the pump would be the limiting factor. In fact all that would be needed to morph to this system would be another FMU and a some spare fittings, and the FMU is in the mail.

 

Good idea! where are the injectors placed?

 

In the piping between IC and intaked manifold