AFR & Boost...
09-21-2010, 07:28 AM
#41
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Typically most good tuners I know will start tuning the motor rich and work they way up leaning it out as it makes power. Most in forced induction will tune the engines to 11.0-11.5 range. Why?.. simple. The wideband takes an average of the air fuel. So if you have two cylinders and one reads 11.8 and the other 11.6 the average is 11.7. Or you have one cylinder 12.0 and the other 11.4.. the average is 11.7. How is this possible, easy.. intake design, throttlebody placement, etc all affect air flow. The LS1 motor with a TB on the front of the engine leads itself to this issue... better is a single plane intake.. but then most pipes feeding the TB will bend at a 90 going into it.
You start going leaner what happens is you stand a better chance picking up detonation. This leads to a whole host of other problems.
You have your choice, what makes the most HP or what makes the engine last longest? Somewhere in between that statement lies your 11.0-11.5:1 AFR
Unless their WB sensor is skewed. I was at a dyno a year ago, S2000 Honda with an AEM computer, AEM wideband gauge, and the tail pipe WB sensor. All three sensors read differently. Point is if the owner of the vehicle paid attention to the tail pipe one and made his adjustments based on that sensor, he would have had an engine meltdown.
The meth/water/meth injection is something else. If you spray straight meth, you bring down your target. Methanol is 7:1 for a stoich. Gasoline is 14.7;1. So as you increase the volume of meth being shot in, your target goes down. On mine I run 10.5-10.8:1 AFR on pump fuel with straight methanol injection 800 RWHP. Displacing approx 20% of my fuel with the meth. So I use 80 % gas and 20% meth. If you spray less meth, then you move your target up.
Water is another deal.. as water will lean out the motor. Most on water will run higher AFR's. 50/50 mix you stay with your current target.
Easy way to look at this, tune to max HP leaning it out and back it down a touch. The further you back it down, the higher cushion you have for slight mistakes.
You start going leaner what happens is you stand a better chance picking up detonation. This leads to a whole host of other problems.
You have your choice, what makes the most HP or what makes the engine last longest? Somewhere in between that statement lies your 11.0-11.5:1 AFR
Unless their WB sensor is skewed. I was at a dyno a year ago, S2000 Honda with an AEM computer, AEM wideband gauge, and the tail pipe WB sensor. All three sensors read differently. Point is if the owner of the vehicle paid attention to the tail pipe one and made his adjustments based on that sensor, he would have had an engine meltdown.
The meth/water/meth injection is something else. If you spray straight meth, you bring down your target. Methanol is 7:1 for a stoich. Gasoline is 14.7;1. So as you increase the volume of meth being shot in, your target goes down. On mine I run 10.5-10.8:1 AFR on pump fuel with straight methanol injection 800 RWHP. Displacing approx 20% of my fuel with the meth. So I use 80 % gas and 20% meth. If you spray less meth, then you move your target up.
Water is another deal.. as water will lean out the motor. Most on water will run higher AFR's. 50/50 mix you stay with your current target.
Easy way to look at this, tune to max HP leaning it out and back it down a touch. The further you back it down, the higher cushion you have for slight mistakes.
09-21-2010, 08:13 AM
#42
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Typically most good tuners I know will start tuning the motor rich and work they way up leaning it out as it makes power. Most in forced induction will tune the engines to 11.0-11.5 range. Why?.. simple. The wideband takes an average of the air fuel. So if you have two cylinders and one reads 11.8 and the other 11.6 the average is 11.7. Or you have one cylinder 12.0 and the other 11.4.. the average is 11.7. How is this possible, easy.. intake design, throttlebody placement, etc all affect air flow. The LS1 motor with a TB on the front of the engine leads itself to this issue... better is a single plane intake.. but then most pipes feeding the TB will bend at a 90 going into it.
You start going leaner what happens is you stand a better chance picking up detonation. This leads to a whole host of other problems.
You have your choice, what makes the most HP or what makes the engine last longest? Somewhere in between that statement lies your 11.0-11.5:1 AFR
Unless their WB sensor is skewed. I was at a dyno a year ago, S2000 Honda with an AEM computer, AEM wideband gauge, and the tail pipe WB sensor. All three sensors read differently. Point is if the owner of the vehicle paid attention to the tail pipe one and made his adjustments based on that sensor, he would have had an engine meltdown.
The meth/water/meth injection is something else. If you spray straight meth, you bring down your target. Methanol is 7:1 for a stoich. Gasoline is 14.7;1. So as you increase the volume of meth being shot in, your target goes down. On mine I run 10.5-10.8:1 AFR on pump fuel with straight methanol injection 800 RWHP. Displacing approx 20% of my fuel with the meth. So I use 80 % gas and 20% meth. If you spray less meth, then you move your target up.
Water is another deal.. as water will lean out the motor. Most on water will run higher AFR's. 50/50 mix you stay with your current target.
Easy way to look at this, tune to max HP leaning it out and back it down a touch. The further you back it down, the higher cushion you have for slight mistakes.
You start going leaner what happens is you stand a better chance picking up detonation. This leads to a whole host of other problems.
You have your choice, what makes the most HP or what makes the engine last longest? Somewhere in between that statement lies your 11.0-11.5:1 AFR
Unless their WB sensor is skewed. I was at a dyno a year ago, S2000 Honda with an AEM computer, AEM wideband gauge, and the tail pipe WB sensor. All three sensors read differently. Point is if the owner of the vehicle paid attention to the tail pipe one and made his adjustments based on that sensor, he would have had an engine meltdown.
The meth/water/meth injection is something else. If you spray straight meth, you bring down your target. Methanol is 7:1 for a stoich. Gasoline is 14.7;1. So as you increase the volume of meth being shot in, your target goes down. On mine I run 10.5-10.8:1 AFR on pump fuel with straight methanol injection 800 RWHP. Displacing approx 20% of my fuel with the meth. So I use 80 % gas and 20% meth. If you spray less meth, then you move your target up.
Water is another deal.. as water will lean out the motor. Most on water will run higher AFR's. 50/50 mix you stay with your current target.
Easy way to look at this, tune to max HP leaning it out and back it down a touch. The further you back it down, the higher cushion you have for slight mistakes.
09-21-2010, 09:03 AM
#43
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Probably a few more reasons in there
Just have had some issue with mix and getting it right.. temps change 20 degree's and i'm fiddling with the tuneup again. With straight alcohol.. set it and forget it. 
09-21-2010, 09:11 AM
#45
Typically most good tuners I know will start tuning the motor rich and work they way up leaning it out as it makes power. Most in forced induction will tune the engines to 11.0-11.5 range. Why?.. simple. The wideband takes an average of the air fuel. So if you have two cylinders and one reads 11.8 and the other 11.6 the average is 11.7. Or you have one cylinder 12.0 and the other 11.4.. the average is 11.7. How is this possible, easy.. intake design, throttlebody placement, etc all affect air flow. The LS1 motor with a TB on the front of the engine leads itself to this issue... better is a single plane intake.. but then most pipes feeding the TB will bend at a 90 going into it.
You start going leaner what happens is you stand a better chance picking up detonation. This leads to a whole host of other problems.
You have your choice, what makes the most HP or what makes the engine last longest? Somewhere in between that statement lies your 11.0-11.5:1 AFR
Unless their WB sensor is skewed. I was at a dyno a year ago, S2000 Honda with an AEM computer, AEM wideband gauge, and the tail pipe WB sensor. All three sensors read differently. Point is if the owner of the vehicle paid attention to the tail pipe one and made his adjustments based on that sensor, he would have had an engine meltdown.
The meth/water/meth injection is something else. If you spray straight meth, you bring down your target. Methanol is 7:1 for a stoich. Gasoline is 14.7;1. So as you increase the volume of meth being shot in, your target goes down. On mine I run 10.5-10.8:1 AFR on pump fuel with straight methanol injection 800 RWHP. Displacing approx 20% of my fuel with the meth. So I use 80 % gas and 20% meth. If you spray less meth, then you move your target up.
Water is another deal.. as water will lean out the motor. Most on water will run higher AFR's. 50/50 mix you stay with your current target.
Easy way to look at this, tune to max HP leaning it out and back it down a touch. The further you back it down, the higher cushion you have for slight mistakes.
You start going leaner what happens is you stand a better chance picking up detonation. This leads to a whole host of other problems.
You have your choice, what makes the most HP or what makes the engine last longest? Somewhere in between that statement lies your 11.0-11.5:1 AFR
Unless their WB sensor is skewed. I was at a dyno a year ago, S2000 Honda with an AEM computer, AEM wideband gauge, and the tail pipe WB sensor. All three sensors read differently. Point is if the owner of the vehicle paid attention to the tail pipe one and made his adjustments based on that sensor, he would have had an engine meltdown.
The meth/water/meth injection is something else. If you spray straight meth, you bring down your target. Methanol is 7:1 for a stoich. Gasoline is 14.7;1. So as you increase the volume of meth being shot in, your target goes down. On mine I run 10.5-10.8:1 AFR on pump fuel with straight methanol injection 800 RWHP. Displacing approx 20% of my fuel with the meth. So I use 80 % gas and 20% meth. If you spray less meth, then you move your target up.
Water is another deal.. as water will lean out the motor. Most on water will run higher AFR's. 50/50 mix you stay with your current target.
Easy way to look at this, tune to max HP leaning it out and back it down a touch. The further you back it down, the higher cushion you have for slight mistakes.
With regards to targeting 11.8 off meth and 11.2 on meth. This isn't a bad idea because should you run out of meth or the system fail to activate, you aren't running into an overly lean condition. But this is not the rule of thumb as many use meth to supplement an undersized fuel system. So for instance, let's say that you are at 90% injector duty cycle at 15psi of boost but you want to run 20 psi. Instead of adding fuel, you add meth to compensate so now you aren't buying new injectors, more pump or increasing fuel line size to accommodate the additional power. Think of it as a standalone fuel system.
09-21-2010, 10:05 AM
#46
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The red part is incorrect. On a meth scale 7:1 may be stoich for meth but on a gasoline scale, it's still 14.5 ish. Most will keep the wideband on a gas scale as that is the primary fuel so you will target the same 11.5 no matter what you introduce, be it race gas, meth, e85 and/or water.
With regards to targeting 11.8 off meth and 11.2 on meth. This isn't a bad idea because should you run out of meth or the system fail to activate, you aren't running into an overly lean condition. But this is not the rule of thumb as many use meth to supplement an undersized fuel system. So for instance, let's say that you are at 90% injector duty cycle at 15psi of boost but you want to run 20 psi. Instead of adding fuel, you add meth to compensate so now you aren't buying new injectors, more pump or increasing fuel line size to accommodate the additional power. Think of it as a standalone fuel system.
With regards to targeting 11.8 off meth and 11.2 on meth. This isn't a bad idea because should you run out of meth or the system fail to activate, you aren't running into an overly lean condition. But this is not the rule of thumb as many use meth to supplement an undersized fuel system. So for instance, let's say that you are at 90% injector duty cycle at 15psi of boost but you want to run 20 psi. Instead of adding fuel, you add meth to compensate so now you aren't buying new injectors, more pump or increasing fuel line size to accommodate the additional power. Think of it as a standalone fuel system.
The 11.8 without and 11.2 with only applies to applications that are not tuned reliant on methanol. Meaning if your pushing 28 PSI boost on your LS1 you'll never achieve this. One becuase it wont stay together at 11.8 straight pump fuel, and two.. the amount of methanol shot in will impact the air fuel way over .6 pioints. More like 10.5:1 afr with and 13.5:1 afr without. As you need about 20% fuel displacement to have it not knock.
If you have an LS1 with lets say a maggie.. and you want to add a little insurance.. then the 11.8 without and 11.2 with will work. As you move away from being able to run the engine on pump fuel boost wise.. the volume of methanol has to increase.. as it increases so does the engines reliance on the system.
09-21-2010, 10:12 AM
#47
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Only if you like tuning year round. Better not use it in winter time when the temps drop.
methanol changes phase at 70 degree's
water changes at 180 degree's
meaning the air going over the nozzle has to have sufficient temp to make the liquid change phase into a gas.. if it doesnt.. then you have distribution problems.
Example.. LS1.. you shoot liquid out of a nozzle.. IF it stays in liquid form.. it goes to the back of the intake. If it changes phase.. it distributes evenly.
I use the analogy of brake cleaner and a hot brake rotor. Shoot some brake cleaner on a hot rotor.. it disappears. Shoot water.. it stays wet unit il it evaps.
So what happens.. its 30 degree's outside, your at 6 PSI boost=IAT are maximum 90-100 dgree's.. not enough temp to make water mixes work. Unless your talking 90% meth and 10% water.
You'll be breaking ring lands screwing around with water injection in winter time on an LS motor. Meth injection is a different story. Dont mix the two
methanol changes phase at 70 degree's
water changes at 180 degree's
meaning the air going over the nozzle has to have sufficient temp to make the liquid change phase into a gas.. if it doesnt.. then you have distribution problems.
Example.. LS1.. you shoot liquid out of a nozzle.. IF it stays in liquid form.. it goes to the back of the intake. If it changes phase.. it distributes evenly.
I use the analogy of brake cleaner and a hot brake rotor. Shoot some brake cleaner on a hot rotor.. it disappears. Shoot water.. it stays wet unit il it evaps.
So what happens.. its 30 degree's outside, your at 6 PSI boost=IAT are maximum 90-100 dgree's.. not enough temp to make water mixes work. Unless your talking 90% meth and 10% water.
You'll be breaking ring lands screwing around with water injection in winter time on an LS motor. Meth injection is a different story. Dont mix the two
09-21-2010, 11:03 AM
#48
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Let me throw this out there, I run 100% meth and keep my afr's 10.0-10.8, when I pull my plugs they are usually a very slight tan, running the meth does it create a cleaner lighter pattern on the plugs?
I'm thinking 10.0-10.8 I would see a darker slightly brwn plug.
I'm thinking 10.0-10.8 I would see a darker slightly brwn plug.
09-21-2010, 03:47 PM
#49
Julio, you are correct with regards to 28 psi and pump gas not working out and the amount needed to relieve detonation (maybe depending on the combo) but as far as target air fuel goes, regardless of methanol, gasoline or E85, (if the wideband is on a gas scale) you will want to target that same 11.5 number.
09-22-2010, 07:18 AM
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The wide band reads air fuel.
If the wide band reads air fuel, it doesnt care if the fuel is gasoline or methanol.
The stoich on methanol is 7:1, ethanol is like 8.5:1, gasoline is 14.7:1. Each of these fuels have a different stoich. This is why you consume twice as much methanol as you do gasoline to make the same power.
You tune at a lower number than stoich to make the engine live. Technically you'd make max power on a perfect engine over 13:1 air fuel. But we all know you dont go that high especially on forced induction becuase of distribution issues. So if you tune using gasoline at 11.5, on Methanol you'd tune at 5.5:1 since that is a number lower than stoich.
So as you introduce a fuel with a lower stoich, you reduce your target.
Not that you can run 11.5:1 with pump gas and methanol, as your volume of methanol increases.. down goes the target. This is where how much volume being shot in is the key. You take a system with a 1 gph nozzle at 100 psi pressure vs a system with 30 gph nozzle at 150 PSI.. you can see where this is going.
If you take a motor that maxes out at 11.5:1 af and you displace 20% of the fuel with methanol, it wont make max power at 11.5:1 anymore.
I had a video of a 291 CI V6 Chevy motor with an 88 MM turbo.. made 1100 HP on 91 octane + methanol inj at 10.0:1 AF. Not 11.5.
If the wide band reads air fuel, it doesnt care if the fuel is gasoline or methanol.
The stoich on methanol is 7:1, ethanol is like 8.5:1, gasoline is 14.7:1. Each of these fuels have a different stoich. This is why you consume twice as much methanol as you do gasoline to make the same power.
You tune at a lower number than stoich to make the engine live. Technically you'd make max power on a perfect engine over 13:1 air fuel. But we all know you dont go that high especially on forced induction becuase of distribution issues. So if you tune using gasoline at 11.5, on Methanol you'd tune at 5.5:1 since that is a number lower than stoich.
So as you introduce a fuel with a lower stoich, you reduce your target.
Not that you can run 11.5:1 with pump gas and methanol, as your volume of methanol increases.. down goes the target. This is where how much volume being shot in is the key. You take a system with a 1 gph nozzle at 100 psi pressure vs a system with 30 gph nozzle at 150 PSI.. you can see where this is going.
If you take a motor that maxes out at 11.5:1 af and you displace 20% of the fuel with methanol, it wont make max power at 11.5:1 anymore.
I had a video of a 291 CI V6 Chevy motor with an 88 MM turbo.. made 1100 HP on 91 octane + methanol inj at 10.0:1 AF. Not 11.5.
09-22-2010, 07:22 AM
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now this is getting good. i wish i wouldve been on a dyno when we were tuning on mine, i really felt like i made more power when my AFR was around 10.5-10.8 vs. 11.5 etc.
We literally ran back and forth across a bridge out in bfe and dig to dig to dig to dig, it felt stronger everytime we through a little more fuel in her. finally my tuner quit, becuase he was scared that we would wash the cylinder walls.
We literally ran back and forth across a bridge out in bfe and dig to dig to dig to dig, it felt stronger everytime we through a little more fuel in her. finally my tuner quit, becuase he was scared that we would wash the cylinder walls.
Last edited by JAX04; 09-22-2010 at 07:24 AM. Reason: finally
09-22-2010, 07:30 AM
#52
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I dont think you can wash off cylinder walls unless you are well into the 9's for AFR at WOT.
Most of the time, you kill the cylinders when running rich at idle and cruise.
Its like a BBQ.. got to throw some gasoline in there to make a fire
In this case methanol 
Most of the time, you kill the cylinders when running rich at idle and cruise.
Its like a BBQ.. got to throw some gasoline in there to make a fire
In this case methanol
09-22-2010, 07:35 AM
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yeah, at the time i didnt know, i hadnt read much on tuning and was still learning and still am. thats why i always try to follow these threads and see where they end up. E85 always seems to cause some arguments (for lack of a better word) and i love to see the different outlooks and opinions.
like i said, i had no dyno but the logs showed improvement in acceleration the richer we went. im talking a tenth here and a hundredth there. it wasnt drastic, but by the time we were finished, judging by the logs, we had improved the tune.
like i said, i had no dyno but the logs showed improvement in acceleration the richer we went. im talking a tenth here and a hundredth there. it wasnt drastic, but by the time we were finished, judging by the logs, we had improved the tune.
Last edited by JAX04; 09-22-2010 at 07:41 AM.
09-22-2010, 07:42 AM
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and now, since im not on anybodies side, so to speak, julio, are you saying that running E85 at 11.0 on a gas wideband is running incredibly lean??
Last edited by JAX04; 09-22-2010 at 07:48 AM.
09-22-2010, 08:29 AM
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im wondering the same thing here guys, and i cant wrap my head around how someting with 75% less gasoline can be accuratley read on a sensor that is calibrated for gasoline.
i just dont get that. and sense i do know about the stoich of the different fuels, it makes even less sense. damn it hate being stupid.
i just dont get that. and sense i do know about the stoich of the different fuels, it makes even less sense. damn it hate being stupid.
09-22-2010, 08:54 AM
#57
Julio, you are either not understanding what I am saying or are confused as to how a wideband works. Widebands read lambda and depending on what fuel scale you set it on will depend on the displayed values. So, if you are running a 93 octane tune + methanol @ WOT, you will logically have the wideband set on a gasoline scale. 14.7 displayed on the screen of a wideband set on a gasoline scale is stoich for ANY fuel that you happen to be using. So if the motor was running on 100% methanol, you will want to see 14.7 on a gas/petrol scale if you are targeting stoich. If that wideband was set up to dispaly methanol, it would read 6.4 instead of 14.7 because both of those values = 1.0 Lambda. Like NicD said, sometimes certain fuels tend to want to run a little richer or leaner with certain combos to make max power. I would NEVER recommend that someone run their car at 10:1 AFR with a 4:1 ratio of 91/93 to methanol. That is WAY rich unless the plugs were telling me something drastically different than the wideband. On a new motor 10:1 can wash out the cylinders. For straight methanol, I'm seeing some say going as rich as 9's on a gas scale but I'd have to verify that on a dyno as my track results with E85 have shown to be better on the leaner side as well.
Last edited by 98Z28CobraKiller; 09-22-2010 at 09:03 AM.
09-22-2010, 09:16 PM
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Every wide band reads lambda, period, no exceptions - ever. That is just how it is, it is not open to debate, it is a fact. Since 11.5 is a good WOT gasoline AFR that calculates out to be a .78 lambda (11.5/14.7). The sensor reads .78 and multiples by the fuel stoich which is 14.7 AFR. In the Innovative LC1, and many others I'm sure, you can change the stoich value with the software it came with. So, to summarize, you want to target the same lambda while spraying meth, for best results. It may not be the safest for your motor in the event of running out, but it will make more power. I hope this makes sense.
