Meth injection tuning.

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DrTal

New member
I have a question on how to tune for an electric turbo.
I'm relatively new to tuning but after looking around using meth for the kit would be ideal.
Basically running meth + the electric turbo as similar to a wet nos kit.

The issue I'm trying to figure out is how to tune for it so that when the electric turbo/meth isn't turned on it doesn't affect your stock fueling map.
I would like to be able to run my vehicle like normal then when activating the turbo kit meth is injected via how much boost the turbo is putting out and the stock fueling would not need to adjust much as equal parts fuel/air would be injected so afr wouldn't spike one direction or the other.

Any tips or direction for this would be appreciated. As I don't see much information on how to tune for a kit that is only on some of the time.
 
I don't have E-turbo experience yet (I join this forum to change that!) but i do have with turbo+meth injection.
You cannot manage fuel addition just base on boost because it isn't a measure of air flow but a measure of engine restriction.
You need more data with pressure to evaluate fuel needs. Cars without mass sensor use Throtle position, RPM and MAp pressure to achieve it but newer rely on mass air flow sensor for coarse control. Then you need the fuel map to know if you are looking for 11-12 or 14.7 afr in that x-y-z conditions etc. but you could get away with just a coarse fuel control for extra air and let factory ecm manage the fine tuning.

As a resume, basic methanol controller based on boost are just good enough to serve as a start/stop function switch.
To manage balanced fueling, you would need more complex meth controller. Some exist, if you look into stage3+ from well known methanol brand or i'm using one from Torqbyte. Those would read extra datas to make a real working fuel map based on your setup.

I'm personally using it as extra fueling to help my limited high pressure injectors. I don't want to suddenly add extra fuel when boost happen to mess the factory system. i use the progressive mapping to add a linear amount of fuel per air flow and tune to cheat the factory ecu in seeing less air flow to remove some factory fuel compensated by the methanol content. (keeping in mind pur methanol has less btu per volume than fuel and get worst with addition of water)

In your case, if you have a car without a maf, it won't see much more of the boost than the intake map like going at sea level so a 3d mapping for methanol sound correct.
If your car is equipped with a maf like mine and the eturbo is using it, the car will see the extra air flow and try to add fuel to compensate as much as it can. If you add fuel on your side, it will run into lower afr (rich) and use the exhaust wideband (when equipped) to reduce the gas amount after some time. That would work better after ecu learning but if you stop using it, the ecu learning will go backward again. (Fuel trim)
At this point, a switched methanol system with a small amount of juice for low boost addition to help knock and cool the charge, may work as good as a complex system fighting against a modern ecm as long as you aren't going outside of factory fueling system capacity.

If you plan a lot of boost and/or methanol, you would need to do something for factory ecm or you would need a by pass valve system to have the boost coming in outside of the maf reading and compensate with methanol content like you was looking to do from the beginning.

I did also see some peoples reducing the maf hosing diameter to compensate larger injectors or similar instead of remapping ecu but to match this with extra fueling could be tricky..
 
DrTal said:
I have a question on how to tune for an electric turbo.
I'm relatively new to tuning but after looking around using meth for the kit would be ideal.
Basically running meth + the electric turbo as similar to a wet nos kit.

The issue I'm trying to figure out is how to tune for it so that when the electric turbo/meth isn't turned on it doesn't affect your stock fueling map.
I would like to be able to run my vehicle like normal then when activating the turbo kit meth is injected via how much boost the turbo is putting out and the stock fueling would not need to adjust much as equal parts fuel/air would be injected so afr wouldn't spike one direction or the other.

Any tips or direction for this would be appreciated. As I don't see much information on how to tune for a kit that is only on some of the time.
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First understand that you do not require as much boost with an electric turbo than you do a traditional turbo or supercharger, so the quantity of additional fuel management needed is much less, as a result of the absence of parasitic horsepower used by a turbine housing, or supercharger belt drive. I've been here many times with a traditional turbo and wouldn't run one without water/methanol injection due to the number of benefits offered; cooler intake charge, increased octane rating, steam cleaned combustion chamber and smooth combustion pulses from a more efficient combustion process.

Variable water methanol injection does not require extremely sophisticated equipment, there are variable rate controllers available that can be metered with a MAP sensor circuit that is translated into pulse width modulation (PWM) via boost pressure (voltage). Most important of all, you need a wide band O2 controller to tune the rate of delivery to avoid burning valves from running lean, and damaging rings and pistons. I use Zeitronix which provides software for datalogging and has an auxiliary circuit that is programmable for a specific trigger point. PLX is a quality option as well but not sure on software.

Ultimately your engine management system will determine what approach is best. Many modern vehicles use a torque based engine management system which is not as straightforward to tune as the old OBDI system which had simple spark and fuel table layouts and a MAP circuit to vary the injection pump speed might need to be replaced with an accelerator pedal position voltage (say 75% activation point) as a result of the effects of variable valve timing which can result in wide open throttle at a very low speed and camshaft position to maximize torque at part throttle for efficiency. That way at 75%+ throttle there's no confusion about your intentions.

Here's something to consider, https://www.ebay.com/itm/225476379385
 
If you're not in boost, then your stock maps aren't affected. I've been running my methanol setup to turn on and off with the electric supercharger. It does spike the AFR rich while the electric supercharger spools up; but it's so quick that it's not an issue - thick accel pump shot. I can also speed up the spool up time, but that would be harder on the ESC and also getting traction. If you have no way to pull back on the fuel in your car, you can run less meth - just enough to compensate for the additional airflow. It would take some nozzle size experimentation or a PWM controller as mentioned above to dial in. This also assumes your car's ECU won't freak out at seeing boost.

At these relatively low boost levels, meth isn't really all that necessary in most cases. You could also go very old-school and do a meth injection kit similar to the old Anderson Mr. Freeze setup - that basically uses boost pressure to push meth into the system pre-compressor. But at these low boost levels, you'll be relying on the electric supercharger to atomize the meth. Not great, but not terrible - some erosion of the impeller will occur, but most likely nothing significant in the life of the car. On my youtube channel I built a similar system years ago for the Whipple setup, but I never installed it.

There seems to be a lot of interest in a "progressive" type setup - both boost and meth. That wouldn't be hard to implement, but it's pointless on my car - I never encounter a situation where I need more than 500hp and less than 750hp. If I had access to the Nürburgring, then perhaps. But at the end of the day it would still be a 1984 Foxbody Ford LTD - you'd be taking your life into your own hands at that point.
 
Simplest way is just on-off switching. You get more meth per cycle at low revs but you need more. Detonation is more prevalent at low revs.

Use 50:50 water:meth. The AFR will only be affected half as much. You won't need as much as you would with straight meth so the effect is even less than half. If you only have mild det' just use straight water. Straight water will suppress at least 5 psi worth of det' so if your motor is just starting to detonate at 5 psi, the right amount of water will allow you to run at least 10 psi without det'. Straight water has no effect on the AFR. Going to 50:50 will give you at least another 5 psi. Straight meth has no advantage over 50:50 unless you can start reducing the primary fuel to add more meth.
 
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gruntguru said:
.... Straight meth has no advantage over 50:50 unless you can start reducing the primary fuel to add more meth.
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I do believe that is incorrect from my experience with it. The question is the benefit ratio of 50/50 mix vs. 100%. The 50/50 ratio has a safety measure involved in that it is not likely to catch fire in the event of a leak near an ignition source.

100% however should have the benefit of the chilling effect on the intake components as it vaporizes (the same benefit I understand E85 has). Some of the Buick Grand National enthusiasts reported frost on the intake manifold from running high percentages of methanol after runs and a good number of them removed the intercooler because it was no longer necessary with the meth system they were using. Ultimately it depends on the system requirements for the boost level.

It's cheaper to run as much water as you can but most power effective to run as much methanol injection as you can. With water you get anti-knock benefit and steam cleaned combustion chambers, with lots of methanol you get anti knock benefit (octane boost) and a chilling effect and the two liquids together offer a happy medium somewhere in between.
 
maticulus said:
With water you get anti-knock benefit and steam cleaned combustion chambers, with lots of methanol you get anti knock benefit (octane boost) and a chilling effect and the two liquids together offer a happy medium somewhere in betw
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just thinking aloud here ... this is not from experience.
Would it be fair to say that while water does a better job of reducing knock on its own, methanol allows more liquid to be injected into the combustion chamber (without drowning the engine) which in turn allows more power to be made without knock? The reason to have water there is to 1/maximum anti knock effect per dollar 2/ reduce the inherent danger of methanol as a fuel 3/ clean the combustion chamber?
 
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brettus8 said:
just thinking aloud here ... this is not from experience.
Would it be fair to say that while water does a better job of reducing knock on its own, methanol allows more liquid to be injected into the combustion chamber (without drowning the engine) which in turn allows more power to be made without knock? The reason to have water there is to 1/maximum anti knock effect per dollar 2/ reduce the inherent danger of methanol as a fuel 3/ clean the combustion chamber?
Click to expand...
It's pretty much the same thing. It really depends on what you need or want. 50/50 is just how it was always promoted back in the "stone ages" and during injections early use it was just water injection for fighter planes. Now it is probably driven more by marketing benefits to the manufacturers.

In my case I was pushing the limits of high compression with boost, something almost no one does with turbocharging, it's almost always setup inversely, decreasing compression and adding boost. The performance was so impressive in my experience I vowed to never again lower compression for boost. The response from a stand still to letting off the throttle was incredible, and there's also a smoothing effect on the combustion process that can be felt in the seat in the form of a much smoother running motor.

I found a short video that supports what I've said as well as what I've experienced upon accidently running more methanol than I had intended to, the motor ran as if I never reached its peak, it just continued to pull until I let off the throttle. For every 10 degree drop in inlet temps there is a roughly 1% gain in power on top of what the octane increase afford you.

 
Wow ...great video and explanation! For me I really have to stick with some water though, due to safety concerns, plus it really does help my rotary stay nice and clean (preventing compression loss) internally.
Maybe ...for the dyno though......lol
 
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