Larry

iTrader: (4)

I've installed a Snow meth system. Was told with -20 blue windshield washer fluid that I would be able to use the same tune. Slightly richer with meth but ok. Now I'm finding that my afr richens .08-.09 Lambda richer. Around an .85 Lambda without meth to .76 Lambda with meth. Is this what others have experienced? I don't see how I can use the same tune and make power with meth. I would like to keep the same tune just for engine safety.

I have a 2017 C7Z06 Corvette and of course with direct injection.

Realcanuk

Normal. If you don't adjust the tune it will be rich.... no way around that.

stevieturbo

How much mixture changes...will of course depend on how much additional fuel you are injecting relative to main fuel supply.

0.85 Lambda is pretty lean for a boosted application, unless it is very very low boost or race fuel.

0.76 lambda would be a sensible target for a moderate-high boost setup, although this could be leaner with the water/meth injection...again all dependent on quantities used, boost etc etc

Larry

iTrader: (4)

When I ordered it Snow tech told me I should be able to use the same tune. I even leaned my MAF table 1/2% too and still rich.

This -20 I'm using is suppose to be about 30% meth.

I have read and was told that .84-.85 is safe for these direct injected engines. The factory EQ table even has it leaner at some rpms.

At .76 lambda my exhaust pipes get so black now. Did not before the meth so that leads me to feel that .7s is too rich. Getting a lot of kr too. I'm also running a mixture of Boostane to bump the octane to about 100. Assuming Boostane charts are accurate. And before meth I was getting almost zero kr.

stevieturbo

I've never worked on a DI engine, so cant comment there, but have read some people suggest widebands may read a little different on them. How true that is....dont know.

But I guess if a factory stock motor is reading 0.85 lambda, then it should be a safe place to stay near.

As for KR....just injecting the water/meth at whatever time and quantity you are, no other changes...you're seeing this ? And have you listened with det cans or similar to confirm whether this noise is real or false ?
If boost or tuning has not changed, it would be very strange for there to be any odd noises, or indeed knock of any kind itself.

If the washer fluid is only 30% methanol, it would take a huge volume of fluid to richen the mixtures by so much. Are mixtures even across both banks ?

Larry

iTrader: (4)

When I set my afr before meth I tried to match my factory EQ lambda numbers as close as I could.

I'm running a #6 (635 ml/min) nozzle. What Snow recommended for my power rating of about 600 rwhp. I'm only logging one bank.

Here is a snipping of my log with my HP Tuner. Kr in the graph doesn't match the chart for some reason.



Here's what I have logged for kr.

truckdoug

iTrader: (25)

yeah the di motors like 12.5 afr, seen it just recently. pull some more fuel out and read some plugs

jimmyg

Larry

iTrader: (4)

Wow, 12.5 down to 11.2-11.5 is more than I've logged. Looks like what I am seeing is normal with this #6 nozzle.

As I had mentioned, had hoped to run the same tune in case the meth system fails I wouldn't be too lean. No problem adding more fuel but then if I have a meth failure maybe boom! lol But for now I'm going to dial my afr in and see how much more power I get. Maybe the system is reliable.

Luke19901

with meth you're adding fuel through the nozzle/s of course it will be richer.

meth injection is rubbish. get a decent charge air cooling product

gametech

iTrader: (1)

If you run the same tune then adding meth injection is useless. Think about it. You are trying to make your system safer/more power/whatever, without tuning for more power or lowering horsepower. You are adding complexity for absolutely zero benefit. What is the point?

Larry

iTrader: (4)

My goal in the beginning by adding the system was to be able to make the power the engine is suppose to. Added power would be nice too but just not losing the power I have due to heat soak is a gain in power. Running straight water should do that. This #6 nozzle may be too large for my power level.

stevieturbo

Running straight water and not re-tuning to make use of it, will pretty much always reduce power.

You need to retune and add timing ( and/or boost ) to see gains from the knock suppression abilities of the water. Assuming the engine/fuel combo was knock limited in the first place.

Possibly the only time gains might be seen without retuning, would be with very small amounts of water, and if charge temps were extremely hot.

Larry

iTrader: (4)

Don't plan on running straight water. It may freeze anyway. My plan now is to call their tech line and see what they recommend for a safe system. I would guess at this point that I will have to run a smaller nozzle, add more water to my -20 fluid or tune. And right now I'm in the stages of dialing in my afr and timing without diluting with water to see how much power I can get. But to do that I will not have a safe system should the meth fail.

stevieturbo

If you are adding meth/water to a known good running engine....it should be safe anyway.

So adding safety to a safe setup ? If the AFR's are too rich for your liking with the water/meth mix you are using or intend to use, then yes the easiest fix is to inject less liquid.

But whilst water alone can be used, throwing water into your fire will of course have negative effects. Hence some sort of W/M mix makes more sense. You can have the positive effects of injecting the liquid, without any of the real negatives of water alone on a setup where you do not intend to retune to make the most of the injection.

truckdoug

iTrader: (25)

on a DI motor at least the valves won't get all grody like usual

I think the real solution here is to turn the boost up until AFRs fall back into line

stevieturbo

Sounds like a plan

Larry

iTrader: (4)

That would be good but that's a pulley change and I already have an overdrive crank pulley. I'll see if Snow tech has a solution.

Here's what a tuning company called Shortuning recommends: http://www.shortuning.com/

"I would purchase an E85 emulator box from DSTeck and wire it in so that when Methanol sprays it triggers E85 mode in the ECM. This will give you access to tables that you can pull fuel and add timing with. It's the safest method so that if the meth doesn't spray or build pressure then it doesn't pull fuel from the injector or add timing for the Methanol."

truckdoug

iTrader: (25)

hmmm im not sure I like that added level of complexity...you're gonna have to tune all those spark adders and fuel tables preferably with a load bearing dyno

Larry

iTrader: (4)

I have to agree with you on the complexity of his method. It was just something I read about. Probably cost big bucks to get it done if you didn't know how or had no instructions. Hopefully I can find an easier way to achieve what I want.