chuyler1

iTrader: (1)

I haven't had much luck finding info related to this, mostly because everyone says "just premix" but that's a hassle I don't want on a daily driver. I would like to incorporate the OMP into an EFI setup. The forum threads I have found such as this one suggest tapping into your carburetor float chambers and letting the oil mix with the fuel. Obviously that technique doesn't work with fuel injection. I was thinking the next approach would be to just dump the oil into the intake but the same thread mentions occasional smoking. So finally, I thought maybe I should start with the approach seen in the photo below, but instead of using generic barbs, tap the holes to accept later gen oil injectors. I know it's not as good as injecting at the ports, but do you think the oil will atomize better if I also hooked up vacuum lines so air was pulled through just like stock setup on later gens? And as for the "just premix" crowd, I eventually want to incorporate a bypass adapter so I can pull in premix from a separate reservoir.

Jeff20B

iTrader: (13)

Make sure the holes in your oil injectors aren't tiny like the ones in the FC and later rotor housings, These will blow out the seals and o-rings in your OMP. Also make surer your oil lines are't huge ID as that will allow the oil in them to drain back down into the engine by gravity. What you want is an ID small enough to allow capillary action to hold the oil in place so you don't have dry starts. Copy what Mazda did on the Nikki if you can.

chuyler1

iTrader: (1)

So what would you recommend for injectors? Is there a part number from a specific year I should shoot for? ...assuming I only use 2 instead of the 4 used by later models.

Jeff20B

iTrader: (13)

The injectors found in the lower intake manifold of the S4 NA are a good choice if you can figure out a way to use them. They have the big orifice you want. Hmm, maybe the other set found on the rotor housings also have the orifice. Either way, as long as you aren't using the brass inserts found in the rotor housings themselves with the ultra small orifice, you will probably be ok. Have you seen how tiny they are? These are responsible for blowing out the OMPs designed for carbs as they were never designed to be used with them. I've corrected several of these over the years when the previous owner wanted to use the rotor housing injectors and ended up with a massive oil leak on his front cover from the OMP as a result.

chuyler1

iTrader: (1)

Well I guess the size of the orifice could be drilled larger on any of these...but only to the point where the air passing through from the vacuum line doesn't hinder idle speed. With large unrestrictive vacuum ports like the photo above, I doubt back pressure is an issue at all, but then the oil just dribbles in instead of getting sprayed by a small amount of air mixture.

rxtasy3

iTrader: (2)

unless u can somehow figure a way to use the electric type omp, but the mechanically actuated type like on the 12a can't be used due to the tps being on that side of the throttle body. that's one of the issues that's kept me from using these setups. in the above pix, the omp lines see vacuum. and also missing the actuator rod.

chuyler1

iTrader: (1)

I don't have pictures but I did see one owner on Facebook use a throttle cable to actuate the OMP. You just need a bracket to mount above the OMP, and another to connect it to your throttle linkage. With my setup, I have the TPS on the other side so I i think I can make a custom rod to connect it.