Meth injection question. Fuel trimming

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93supercoupe
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Meth injection question. Fuel trimming

Post by 93supercoupe »

Hello fellas

So ive been playing with my meth injection kit. I have it wired so it PWM's the pump and it works well. I am using Meth injection as a cooling aid to supplement my baby intercooler. So when the ambient temps are under 80ish degress F, theres really no need for it.

So i know i can set a minimum MAT temp in the water injection tab, but i was wondering if there is a way that when the MAT goes above a cerrtian temp, it will A. utilize the meth, and B. automatically trim the fuel so it doesnt go rich.

I have enough PW in the meth pump to take up .5 of an AFR. So my target AFR is 11.5, and when my meth turns on it drops to 11.0. Ive figured its about a 1.06% difference between the 2 readings.

So im trying to find a way that when the MAT goes above 80F, it will utilize the meth and minus 1.06% of fuel to maintain my 11.5 AFR target.

IS this possible?

TIA
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nathaninwa
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Re: Meth injection question. Fuel trimming

Post by nathaninwa »

Two thoughts come to mind quickly. Using the air temp correction chart you could flatline 80*, but that might mess with cruise stuff and other things, or use a programmable output/input and use that to activate alternate reqfuel above 80*. I use that above 150kpa when I stage to race gas and has proven very handy to fine tuning a table before a day of racing
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240Z, 2JZ, MS3Pro boost control
93supercoupe
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Re: Meth injection question. Fuel trimming

Post by 93supercoupe »

I like the reqfuel idea.

I was thinking, along the lines of the same idea, is to wire a low fluid level switch to the same pin i would use as my switch pin for dual fuel

So if the fluid went low, it would go back to its regular AFR table and wastegate pressure.

But as to making it come on over a certian MAT, im not sure how i would still
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nathaninwa
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Re: Meth injection question. Fuel trimming

Post by nathaninwa »

At this point, reqfuel change is hardware only, so setup a programmable output for greater than 80* which will trigger an input to switch reqfuel
Volvo 940, 2jzge, MS3Pro, daily
240Z, 2JZ, MS3Pro boost control
93supercoupe
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Joined: Sat May 10, 2014 4:57 am
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Re: Meth injection question. Fuel trimming

Post by 93supercoupe »

Im finally getting some time to think about this more, and yea that makes sense.

If i could use an outside source to switch at my desired temp, then i could just use dual fuel for an alternate fuel map or just changing the req. fuel.
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93supercoupe
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Re: Meth injection question. Fuel trimming

Post by 93supercoupe »

what if i wired my tableswitch pin to my water injection pump output pin?

That way, when the pump is turned on by its defined values, it grounds the tableswitch pin and goes uses Dual Fuel?

Because the pump output is a ground, so when the MS turns it on, the pump output pin goes to ground, which is what i would need my table switch pin to do.

Does that make sense?
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nathaninwa
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Re: Meth injection question. Fuel trimming

Post by nathaninwa »

I bet either option would work. I reqfuel switch when I stage to race gas
Volvo 940, 2jzge, MS3Pro, daily
240Z, 2JZ, MS3Pro boost control
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