2GR-FKS Direct Injection

Reading up on fuel delivery in my 3rd gen an something hit me.

As I understand it, single fuel pump that supply to a Y in the engine bay. 1 end goes to the port injection "fogger" that fogs into the intake, the other goes to a mechanical pump for direct injection.

The ecu determines when each (or both) are in use. This is why idling will see the engine randomly ramp up (direct injection kicks in) an fall.

So if one could programmatically control that function: ideally a secondary microcontroller that would inform the ecu it's time to switch, or just hijack the electrical signals but also relay the proper responses back to the eco so no trouble codes. One could then permanently disable direct injection.

Going one step further - one could also use that same system, with their own controller for either a nitrous or methanol setup.
A dry nitrous system could easily be worked into the port injection, an have main fuel delivered via the direct injection. Though a wet nitrous system could take advantage of either and utilize the secondary controller to make sure the proper amount of fuel is available at all times.
Methanol/Alcohol would be similar as the dry nitrous but only utilizing the port injection.

Just something I was pondering...am I nuts here?

Only caveat: with this motor being an Atkinson cycle as opposed to an Otto cycle - breathing becomes an issue with alcohol (not so much with nitrous) an you may have to add on some forced induction.

Thoughts?

 

Ummm...... Sure.

 

The port injection is similar to “regular” port injection it doesn’t have an injector in the intake manifold . The injector sprays directly behind the intake valves

 

Why yes, yes you are

 

Screen name checks out...

 

The Atkinson cycle can be tuned out. Similarly, the DI and PI can be tuned to your liking using vF Tuner.

 

Here is an interesting video from Toyota on how the Atkinson Cycle works.

https://www.youtube.com/watch?v=WKKILW3Zj_Y&t=45s

 

Better keep reading.

 

You want to run meth on an underpowered and relatively fragile Tacoma engine? Just making sure I read this correctly

 

Fragile? Some folks ran twin turbo on it.

 

I imagine that it would be easier to install your own nitrous or methanol injectors in the manifold than to utilize the existing system. Plus, those port injectors are there to keep the intake valves clean. Believe me, you don’t want coked up valves and stems.

 

These people who say fragile crack me up. There’s nothing fragile about this engine.

 

Over 1 hp per cubic inch is hardly under powered by any measure. 6000 rpm horsepower
peak doesn't indicate a fragile engine to me. I would like to see how one runs with a small hit of n.o.s.

 

The direct injection allows the engine to run super lean. If you disable it, you may need to also return the fuel maps.

 

The fueling is way more complicated than these 2 graphs. This is stock on a 2018 3.5. I'm not sure what "fuel time" means. It could be duty cycle e.g. miliseconds. The second graph is probably more interesting here since it shows the difference in fuel between the two types of injectors. Note the part about "0" being 100% direct injection.

 

Could you please clarify? Are you saying tacoma runs lean in DI mode?

 

Let me clarify that I'm not an expert in this. When running a traditional engine (carbureted, fuel injected, etc) too lean, NOx emissions go up. Normally A/F is limited to around 14.64:1 while LDI (Lean Direct Injection) allows around 40:1. I don't fully understand the mechanism of being lean and not creating NOx. From what I've read, in lean combustion engines, the excess air acts as a heat sink, which lowers the flame temperature and reduces NOx emissions.

Here is a paper from Toyota, 1996 which talks about D-4 and ultra lean combustion. https://global.toyota/en/detail/7901843
In there, they mention air fuel rations of 50:1

Another area where this technology is used is in jet engines. The GE9X (largest jet engine ever made) uses this same concept to lower NOx and save a ton of fuel. Here is a video clip explaining NOx formation and how the GE jet engine overcomes it.

Skip to 18:20

 

WMI, or water meth injection is often used on forced induction platforms to provide extra fueling capabilities when you don’t have access to e85, which allows for CPI, or charge pipe injection. WMI offers cleaning and cooling benefits over CPI but requires a separate fuel tank vs cpi tapping off the LPFP. It’s also expensive to buy quality methanol. I ran WMI / e40 on my tuned Kia Stinger pushing the motor up past 500 hp. Methanol also has as high as 111 octane vs e85 maxing out around 105. Anyway, yes if you put a turbo or supercharger on the Tacoma it could benefit from this kind of setup but nobody seems to be tuning for it. If you can’t control the MAF / fueling to target the correct AFR you can f’up your motor pretty easily. I run e30 in our family commuter / wife’s daily. It’s a Tucson Hybrid our a 1.6t that will easily roast my Tacoma pushing 25 lbs of boosts. Stock is about 13 - 15. It’s all about octane and keeping timing up.

 

I think all this died after Lexus IS250 fiasco.
2gr-fks is no near these numbers. Tacoma runs on reach side.