LNF 5th injector

[mkriebs]

So, I see there is not a ton about the 5th injectors on here. I am looking to build a kit and have read around, snooped on other forums, got the ideas of guys smarter than me, and now I want to propose my ideas and see if anyone bites.

I see the ZZP and Werks kits, and I am not a real fan, personally. My ideas stem from ideology from the old days with carbs and methanol in drag cars. Part of the good property of running pure methanol (M1 or M5 in this case) is something we call latent heat. Latent heat is the property that whilst evaporating, the fuel takes the energy (heat) out of the air. This is why some people use meth injection, but meth injection alone does not fix the fuel issues. To take full advantage of the latent heat of methanol, the fuel being injected with some time to travel through the intake passages.

Ethanol being an alcohol has a high latent heat property as well, not as good as methanol, but I am not running methanol on my LNF as a sole fuel LOL.

My thought is to properly take advantage of this latent heat property of E85, I should move the 5th injector into the intercooler pipe. I would put it where it is convenient, 6-10" from the throttle body. This will allow the heat to be absorbed by the fuel and in turn, cool the intake charge and add the fuel and octane needed to bypass our fueling issues. Also, this would put some fuel behind the valves which would help keep them clean. I doubt it would provide ALL of the cleaning I would need, but it should help.

So, any ideas? Has anyone set one up differently than the ZZP or Werks kits?

Also, what controller should I be looking at? Werks uses the Split Second controller which looks really nice and would provide nice, computer tuneable control. I see some people using the Devil's Own meth controller, but this would not pulse the injector, would it?

Then, for the tune, any recommendations on how to do this? Of course it would depend on the control of the injector, whether boost/rpm control, or just one of the options.

Thanks!
Matt K

[|V3nom|]

gmtech would be the guy to talk to. i think he either started or perfected it.

[mkriebs]

Yeah, I am PM'ing him. Wasn't sure if anyone else was working with these. Pretty excited to get this going.

[Matt M]

If the meth controller is designed to control a pump, then it won't have the correct duty cycle curve to work with a fuel injector. A typical meth pump does not do anything at low duty cycles, so the controller will come in at a higher duty cycle, maybe 40%. This is not optimum when operating an injector because you end up with a spike that is tough to tune around. Our 5th injector controller was designed specifically to control an injector. It starts at 10% idc and ramps in much smoother. The curve is also designed to make tuning as easy as possible.

Where is your MAF located?

[mkriebs]

Stock right now, but will likely change that this winter/before the 5th injector goes in.

[Matt M]

If you run the maf in the lower charge tube and mount the 5th injector there as well, you will run into maf spikes from fuel hitting the maf, even if the maf is first. Getting on and off the throttle will cause fuel to fall down into the maf at times and cause high readings and resulting spikes in di duty cycles.