Normally when you hear of meth injection, sometimes called water injection, you think of turbocharged cars. This is mostly because of the colling effect it has on the combustion, along with the octane increase. The combination works great for hot, compressed air coming out of the turbo.... especially when the IC is heat-soaked.
Also, this is a great power adder that is does not necessarily take more fuel. In fact, many small turbocharged engines running meth injection get great mileage. Just need to refill the meth mix.... or if you are comfortable with some inconsistency you can just use winter mix washer fluid.

Generally the amount of Meth injected is proportional to the manifold pressure. i.e. as boost increases due to the turbo doing its job, the meth is injected more and more. Generally this is an upward plot that gets steeper as boost rises... somewhat exponentially.

My question is... how do these kits work on NA cars? I know they are out there... do they use manifold pressure as well, and just increase the injection as pressure gets closer to 0 absolute? OR... do they use readings coming off the MAF?

My second question is.... has anyone tried using meth injection for mileage increases rather than power on an NA platform? i.e. add meth as load increases (either through measuring MAF or MAP), and pull fuel in the ECU accordingly to maintain the same AFR.

It seems with Hondata you could compensate for meth injection by changing the fuel tables.... but I am not sure if this application makes sense for our platform. It would be great to get the same power if not more, and increase gas mileage at the same time.

I have not seen or heard of this... and I am sure there is a reason. Anyone have experience with this?

 

I did find this on Snow Performances website

I guess I am interested in fuel substitution rather than cooler charge temps. Like the above quote states, no more than about 10%.
If you can pull a true 10% of fuel from the ECU due to the meth that would be nice, but I don't think it works that way.

 

UUGGHH fit doesn't use a MAF. And unless you get a tunable ECU it's of NO USE because you can't change the advance curve of the ignition lead.

 

Nobody has cracked this ECU? I just figured it had been done already.

Regardless, I still would like some discussion on the concept. Also, you can add any sensors you need, that is not really my concern.

 

I guess the topic does not interest anybody...

 

I got an AFC Neo running on my Fit (recently installed, still not tuned, look for an update this Saturday). Although an AFC Neo doesn't have the ability to directly influence timing, it does howerver indirectly advance or retard timing when the stock ECU compensates for the air/fuel corrections that are made with it. For example, if you lean the car out the ECU will compensate by advancing timing a little bit. By how much is anyone's guess, but it does it.

 

I read on forum here that meth kit is not friendly to the fit due the fact that meth is corrosive and wears down on aluminum. But what car out there doesnt have aluminum parts in the engine...

I myself have been wondering the same thing except could you use a meth kit on a stock engine?