Water/Meth and High boost coming. Time for tuning help/suggestions/experience.
- Thread starter CajunKenny
- Start date
Okay, I almost got cold feet reading IJ's warnings...but after reading everyone's info...and hearing a lot of reassurance about meth injection from the local guys, I'm going to still take the plung in the spring...all my tuning will be done by a professional on a dyno...so here's hoping.
Thanks to CK and others for doing a lot of the initial research...time to start educating myself so that I know the in's out's of this and am prepared.
Thanks to CK and others for doing a lot of the initial research...time to start educating myself so that I know the in's out's of this and am prepared.
Glad you're still on board. The more folks we have doing this the bigger information base we'll have. 
Before you head to the dyno, maybe chat with your tuner and see what experience he's had with straight water. Out where I live, there's only three dynos. One is at a Diesel Shop and one at a mainly Honda Shop and they've never tuned with meth.
Before you head to the dyno, maybe chat with your tuner and see what experience he's had with straight water. Out where I live, there's only three dynos. One is at a Diesel Shop and one at a mainly Honda Shop and they've never tuned with meth.
CajunKenny;1654060 said:Glad you're still on board. The more folks we have doing this the bigger information base we'll have.
Before you head to the dyno, maybe chat with your tuner and see what experience he's had with straight water. Out where I live, there's only three dynos. One is at a Diesel Shop and one at a mainly Honda Shop and they've never tuned with meth.
This is a good suggestion. I know he's tuned meth before for the Hondah's & Ev-oh's...but his specialty is supras...but mostly with race fuel and E85 from what I know. I'll have a chat with him and let you know what he says.
Well, I have officially started my install! I'll update my build thread as I go and will post relevant info here.
Supra0089;1654033 said:
HUGE differemce in using Meth as a Bandaid and being "Tuned" to run with Meth, the former means you're just sloshing a bunch of Meth in to ward off Detonation and accepting the outyput of the engine for what it is, tuned by comparison means the Meth becomes a part of the WOT AFR and any change in that however small will have consequences just the same as if an injector, pump or any part of the regular fuel system lays down.
Straight water gives you the detonation resistance without fear of failure if it stops working as it "should" be setup that the engine will only go into high boost if the Injection system is functional.
IJ.;1654136 said:
Good point. I plan on running the safety shut off sensors & system with my meth, so if anything happens, the boost controller shuts down, or wastegate dumps boost...
Will do. However, this thread will only get "Tuning" and related info. For install pics and such, please see my build thread.
I am currently at the point of building a mounting brace for the pump and a box to house the tank.
I am currently at the point of building a mounting brace for the pump and a box to house the tank.
CajunKenny;1653576 said:
You must not get milk and bread the way I do :evil2: I like to pretend that there is only one loaf of bread and one gallon of milk left in the county... if I don't get them before anyone else, my family may starve... ok ok I am joking... yeah this is the reason I like the idea... used only when needed...
CajunKenny;1653576 said:
So speaking of when needed, does the AEM kit allow you to decide what MP (or at least close) in which it is injected? My thoughts are that it really is a waste below 10psi or so... I will easily build 5-6 lbs in normal driving with a 57trim, I do not want it to inject anything at that time... and yes perhaps I am being lazy by asking... I should just read their website, but my business as been super busy lately so... there is my excuse :icon_bigg
gottadiesel;1656231 said:
Ha ha...no problem. I'm glad to answer!
The AEM's system is progressive. You set a 'Min' and 'Max' boost range and it will progressively inject as boost rises.
When injection begins depends on your tune. Sort of... If you're base tune is 11.5 AFR, then a 50/50 Mix with the proper selected nozzle size should change your tune to 11.0. With this setup, a start injection of 10 psi would be totally safe.
However, if you like pushing the envelope and set your base tune to 12.5 AFR then starting to inject at 10 psi wouldn't be so engine friendly.
Condition two will also have disastrous consequences in the event of injection failure. Where as condition one, your engine might live. "Might"!
CajunKenny;1656331 said:Ha ha...no problem. I'm glad to answer!
The AEM's system is progressive. You set a 'Min' and 'Max' boost range and it will progressively inject as boost rises.
When injection begins depends on your tune. Sort of... If you're base tune is 11.5 AFR, then a 50/50 Mix with the proper selected nozzle size should change your tune to 11.0. With this setup, a start injection of 10 psi would be totally safe.
However, if you like pushing the envelope and set your base tune to 12.5 AFR then starting to inject at 10 psi wouldn't be so engine friendly.
Condition two will also have disastrous consequences in the event of injection failure. Where as condition one, your engine might live. "Might"!
Thanks Kenny! Ok, that makes perfect sense... Of course you know me... As it is I am still running 10.8 to 10.9... So I would probably do 11.2/3 and let it drop to 10.7/8... Better to have a little less power for 150k miles than no power sitting in the shop with a hole in the block:icon_bigg
I run 50/50 and have done weeks, months maybe of research and these are my opinions based upon information i have found and considered.
Methanol is a fuel but it burns in an entirely different manor then gasoline. Water is not a fuel so therefore it will pass threw an engine without any change to the A/F ratio as there is no chemical composition change on its journey.
This is where it gets tricky for tuning as we discussed in PM's. I will discuss at bottom.
Both readings are gathered the same way, the only difference between displaying Lambda and A/F is the scale it is displayed on.
He was running direct port injection. It assures the same volume of injection is delivered to each cylinder. Methanol is corrosive but only in pure quantities. I have researched aluminum tanks and have never seen an actual report of an issue. Running 50/50 should dilute the methanol enough to make it stable with aluminum.
Heres what i have gathered and is my opinion on the topic based upon information i have gathered.
First you need to look at the physics of what happens in a combustion chamber. When the piston moves up on compression the fuel air mixture is compressed. When a substance is compressed, the heat in that substance occupies a smaller space then before therefore the temperature rises.
If your compression ratio is 9:1, its temperature should rise 9 times that of witch it started (for argument sake lats assume theres no outside loss) before it was compressed. Because of this, water is an excellent additive as by half way threw compression it should have been heated enough to convert to steam. When the water goes threw this phase change it absorbs large amounts of heat.
Obviously water should be there somewhere because of how useful it is in making a harsh environment more tolerable for lower octane fuel.
Methanol on the other hand is flammable, higher octane then gasoline and breaks down the surface tension of water so it can separate into a finer mist and blend with air more efficiently.
This all sounds great but adding methanol requires more then just a good measuring cup. Just as running E85 requires a different air fuel ratio (~9.4:1 IIRC) as opposed as straight gasoline, Methanol (as mentioned) has a different stoich (6.4:1) AF ratio and under power (4:1) AF ratio.
Because of this the target AF Ratio changes due to the change in fueling. In order to find out what target AF ratio you should adjust your tune for, you need to know the Percent of fuel being consumed by the engine that is methanol and gasoline.
If you find that 10 (for round numbers sake) percent of the fuel your engine is burning is methanol (without water) then you need to calculate a new target ratio. Say your original target is a safe 11.5:1, and you know methanol's safe AF Ratio is 4:1, the math goes like this.
4:1 or 4 x 10 = 40. 11.5:1 or 11.5 x 90 = 1035. 1035 + 40 = 1075 / 100 = New target AF Ratio of 10.75:1
This is very easy assuming you can easily find out exactly how much of each fuel the engine is burning. Problem is, thats not so easy.
Any questions or corrections feel free to discuss.
gottadiesel;1653004 said:
Methanol is a fuel but it burns in an entirely different manor then gasoline. Water is not a fuel so therefore it will pass threw an engine without any change to the A/F ratio as there is no chemical composition change on its journey.
IJ.;1653023 said:
This is where it gets tricky for tuning as we discussed in PM's. I will discuss at bottom.
CajunKenny;1653277 said:
Both readings are gathered the same way, the only difference between displaying Lambda and A/F is the scale it is displayed on.
Blackdawg;1653451 said:
He was running direct port injection. It assures the same volume of injection is delivered to each cylinder. Methanol is corrosive but only in pure quantities. I have researched aluminum tanks and have never seen an actual report of an issue. Running 50/50 should dilute the methanol enough to make it stable with aluminum.
Heres what i have gathered and is my opinion on the topic based upon information i have gathered.
First you need to look at the physics of what happens in a combustion chamber. When the piston moves up on compression the fuel air mixture is compressed. When a substance is compressed, the heat in that substance occupies a smaller space then before therefore the temperature rises.
If your compression ratio is 9:1, its temperature should rise 9 times that of witch it started (for argument sake lats assume theres no outside loss) before it was compressed. Because of this, water is an excellent additive as by half way threw compression it should have been heated enough to convert to steam. When the water goes threw this phase change it absorbs large amounts of heat.
Obviously water should be there somewhere because of how useful it is in making a harsh environment more tolerable for lower octane fuel.
Methanol on the other hand is flammable, higher octane then gasoline and breaks down the surface tension of water so it can separate into a finer mist and blend with air more efficiently.
This all sounds great but adding methanol requires more then just a good measuring cup. Just as running E85 requires a different air fuel ratio (~9.4:1 IIRC) as opposed as straight gasoline, Methanol (as mentioned) has a different stoich (6.4:1) AF ratio and under power (4:1) AF ratio.
Because of this the target AF Ratio changes due to the change in fueling. In order to find out what target AF ratio you should adjust your tune for, you need to know the Percent of fuel being consumed by the engine that is methanol and gasoline.
If you find that 10 (for round numbers sake) percent of the fuel your engine is burning is methanol (without water) then you need to calculate a new target ratio. Say your original target is a safe 11.5:1, and you know methanol's safe AF Ratio is 4:1, the math goes like this.
4:1 or 4 x 10 = 40. 11.5:1 or 11.5 x 90 = 1035. 1035 + 40 = 1075 / 100 = New target AF Ratio of 10.75:1
This is very easy assuming you can easily find out exactly how much of each fuel the engine is burning. Problem is, thats not so easy.
Any questions or corrections feel free to discuss.
Every once in a while, you come across a post with so much great information that it should be stickied somewhere.
Chunks, my friend, I think you just created one of the aforementioned posts.
GJ
Mike
Chunks, my friend, I think you just created one of the aforementioned posts.
GJ
Mike
The o2 sensor reads the oxygen content of what is left in the exhaust. It doesnt care what fuel its being fed. Why do you change the scale your looking at if lambda remains the same? Why not leave it on gas?
exxample:
Gas stoich at 14.7-1.afr Lambda 1.
Meth stoich at 9-1 afr Lambda 1.
If you tune 100% meth (no gas in the tank) with the wideband reading on the gas scale, you still tune for 12.5 or what ever your goal is... The wideband reading is the lambda voltage X the multiplier. Lambda doesnt change between fuels. Just the scale off which you read it does.
exxample:
Gas stoich at 14.7-1.afr Lambda 1.
Meth stoich at 9-1 afr Lambda 1.
If you tune 100% meth (no gas in the tank) with the wideband reading on the gas scale, you still tune for 12.5 or what ever your goal is... The wideband reading is the lambda voltage X the multiplier. Lambda doesnt change between fuels. Just the scale off which you read it does.
grimreaper;1656698 said:
The real question is, does gasoline and methanol both make best powr at the same level of lambda.
http://www.miataturbo.net/showthread.php?t=35717
This thread is good discussion specifically post 10 witch is the real question.
If best power on gasoline is 12.5, that's .85 lamda. If best power on methanol is 4:1 that's .62.
If that's the case you would need to differentiate the ratio of fuels to a new target air fuel ratio. Using lambda to assume the proper ratios wouldn't work in that case.
I do see what your saying and it does make sence I'm not sure how it would work.
I see I see. I didnt consider that, good point as well. I'm tempted to call a few local tuners..
Nosechunks;1656781 said:
This is the grey area I was talking about earlier in the thread and why it's so important to tune on the Dyno and if mixing Meth/Water to do so very carefully.
I always went on the rich side just to be safe.
Thanks for posting Nosechunks. It's great to hear from someone that's been down this road already...
My thought is that it isn't possible for the average Water/Meth user to know or calculate how much of each fuel is being burned. There are too many variables and the proper equipment and dyno time to determine that would be well out of most of our salary ranges. The best we can do is make informed decisions on what we can do ourselves and what others have done and found.
In my reading, I've found that the 50/50 mix is the best at reducing corrosion and the safest ratio to have on board because of the higher flash point.
As far as tuning goes, it's really no different than tuning with pump gas. The basics are the same, ie: Avoid Lean Conditions, Avoid Rich Conditions, and Tune for optimum power. Quench is probably the most encountered problem with water/meth injection.
I've been on the dyno three times now tuning with our local 92 Octane fuel containing 10% Ethanol. Despite weather differences, my car's MBT is right around 16 psi @ ~11.1 afr. Any more boost than that, and the ECU pulls timing. I'm expecting a much higher MBT with the meth.
Do you happen to have any water/meth dyno sheets to share...coupled with timing data?
In my mind, there are some common rules of thumb; but, none of this should be done without the ability to monitor knock and the TQ curve.
My thought is that it isn't possible for the average Water/Meth user to know or calculate how much of each fuel is being burned. There are too many variables and the proper equipment and dyno time to determine that would be well out of most of our salary ranges. The best we can do is make informed decisions on what we can do ourselves and what others have done and found.
In my reading, I've found that the 50/50 mix is the best at reducing corrosion and the safest ratio to have on board because of the higher flash point.
As far as tuning goes, it's really no different than tuning with pump gas. The basics are the same, ie: Avoid Lean Conditions, Avoid Rich Conditions, and Tune for optimum power. Quench is probably the most encountered problem with water/meth injection.
I've been on the dyno three times now tuning with our local 92 Octane fuel containing 10% Ethanol. Despite weather differences, my car's MBT is right around 16 psi @ ~11.1 afr. Any more boost than that, and the ECU pulls timing. I'm expecting a much higher MBT with the meth.
Do you happen to have any water/meth dyno sheets to share...coupled with timing data?
In my mind, there are some common rules of thumb; but, none of this should be done without the ability to monitor knock and the TQ curve.