Meth or Aux Fuel Rail
 

I am working on finishing my spare intake manifold and have come to a fork. Since it is a spare and time is not a big deal, I want to add in bungs for either meth or a secondary fuel rail.

Car is a 2009 LNF that is getting a 20g turbo.

Help me decide.

Meth is a bandaid, a second fuel rail is more work though.

If you plan on staying with a 20g you can probably get by with meth. A fuel rail will give you much more headroom if you are going bigger in the future.

One of my best friends is a fabricator for a speed shop. Builds tube cars, cages, RB swaps, turbo kits, etc. He is the one that will be doing it.

I was thinking of just using a 2.2 rail cleaned up to have only the test port, mounts, and a -4AN fitting installed.

I have no idea if I will go to a bigger turbo, but I want to have more fuel than not enough.

What fuel will you be running?

93 pump

all i have

If that's all u have then another fuel rail won't do much good, unless ur running not so much boost and timing of u go more power. Ur still gonna be injecting 93 octane if u want better quality fuel to make more power then u wanna run meth if u have nothing better for fuel. It will let u run more timing or boost or both. But I wouldn't put one on each runner unless u have a failsafe gauge for all of them. I'd just drill it in back above the tb.

With a 20g, you'll never need that much fuel to justify running a secondary fuel rail. Even with e85 that's a bit of a of a stretch. Especially when Opels and fuel cam can more than handle that. Let's put it this way....

Even with the added fuel demands of e47, with my car making 470whp, I only need a single 30lb additional injector to keep my fueling in check. With that little injector, my pulse widths never see higher than 6ms and idc never sees higher than 30%.

So long and short of it. Even with a td06, you're likely to never need that much fueling, especially on 93.

Now in the long term, it certainly wouldn't hurt to have a port injected manifold sitting in the parts closet for when you decide to go with an even larger turbo on e85. Then that would be a very viable part to have kicking around.

My other thought is helping keep the valves clean by running fuel over them....


Thank you for all of the info so far, I appreciate it.

Unless you're constantly fueling through the manifold injectors, you're not going to see a serious cleaning effect.

If you went far enough with the throttle to activate them once every time you drove the car, the valves would stay spotless. A little fuel will soften and dissolve any oil before it has a chance to turn to soot on the valves.

That is what I was hoping.
Maybe even use the port injection a little more and the DI a little less for my fueling needs.

DI is superior for actual fueling. It's only real drawback is noise and the fact that it can't support as much fuel due to a smaller injection window. For all practical purposes it's better. But port injection cleans the intake valves, is quiet and expandable. Lexus has been using both on some of its engines for a while now.

It's not a terrible idea, but timing the injectors would require some sort of a standalone system along with an external cps and kps to be optimized and keep the engine happy.

Good point.
At this point I would probably have to move away from just a supplementary injector controller and onto a full standalone to work in tandem.

I vote for the meth option, so long as ethanol is not going to be considered or utilized. Meth can help provide the additional fueling (yes, it's a band-aid and not perfect but still works) and offer additional benefits, which you've already listed.

Good luck man

If u want to keep valve clean get Powell v3 oil seperator and run meth and they will stay clean