higher boost/lower timing - how far is too far?
Oct 29, 2008, 01:52 PM
#46
Water will also make combustion happen later too so you automatically have to add 1-3 degrees too. There was a study done I read where they developed a method of determining angle of peak pressure just by spraying an unmetered amt of water into the charge on a steady load and rpm state.
I would be intrested in seeing that study
Evan Smith
Oct 29, 2008, 02:33 PM
#48
Ofcouse water has no Ron value as it cant predetonate (aka infinite small joke), thats what makes it better than methonal for knock control.
That "cooler combustion temps" is the very power potential you want and need. Unfortunatly we have all been trained that "octane" is uber important to making more power. Its only a part of the equation.
Cooler in cylinders temps mean there is room for more... More boost,timing, leaner AFRS ect. ect. ect. Water has some side effects it not only prevents predet and knock better than "high octane fuel" it also slows the deflageration burn down too so as C6C6CH3vo said you automatically have to add some timing to make it equal out.
You just have to know how to extract the power from the "cooler combustion temps". I personaly have seen stock turbo evo 8 on 87 oct make 350 whp on a mustang dyno just from water injection. Rally cars used 100% H2O injection because of the "cooler combustion temps" H2O provided.
My simple point was to help not argue. Add a little water to your mixture tune it right and get more. More boost more timing and more WHP. If I was making this up then the majority of water meth kits wouldnt say run a 50/50 mix but a 100% meth mix. 100% meth is no better than 100 octane in theory.
Respectfully,
Evan Smith
Oct 29, 2008, 02:34 PM
#49
Sorry but water has a infinite RON as it cant burn, thats higher than meth...
Also the higher Ron resists predet not knock, two completely different things.
You have 2 burns in the engine. 1. Predet 2. Deflageration. Octane (Ron) controls the predet and prevents it. Predet somtimes appears as knock, as our knock sensors are not perfect. DET cans can help clearify.
Deflageration is the burn you want to inhance and build upon without the influance of predet. This is why no race gas company is the same. Anyone can produce good octane numbers. But which ones inhance the burn you actually want to inhance? knock occurs during this burn.
You know what predet is so I wont explain...
Knock is after TDC and after the ignition happens. You ignite the fuel, it starts in one place then spreads to the rest of the cylinder. Knock is when another flame starts on the other side of the cylinder and meets the intal flame head on creating a little boom aka knock.
Knock is produced by mainly (but not always) by hot air being compressed. knock is like predet so its easly confused its just after when the ignition has already happend. Meth helps cool that air therefore reducing knock. Water goes into the cylinder mixes then controls the burn and incylinder temps up to 60*! Water will easly remove more heat than meth in turn reducing knock. All this to Allow you to advance the timing, leaning it out and uping the boost = more power.
Good luck!
Evan Smith
Also the higher Ron resists predet not knock, two completely different things.
You have 2 burns in the engine. 1. Predet 2. Deflageration. Octane (Ron) controls the predet and prevents it. Predet somtimes appears as knock, as our knock sensors are not perfect. DET cans can help clearify.
Deflageration is the burn you want to inhance and build upon without the influance of predet. This is why no race gas company is the same. Anyone can produce good octane numbers. But which ones inhance the burn you actually want to inhance? knock occurs during this burn.
You know what predet is so I wont explain...
Knock is after TDC and after the ignition happens. You ignite the fuel, it starts in one place then spreads to the rest of the cylinder. Knock is when another flame starts on the other side of the cylinder and meets the intal flame head on creating a little boom aka knock.
Knock is produced by mainly (but not always) by hot air being compressed. knock is like predet so its easly confused its just after when the ignition has already happend. Meth helps cool that air therefore reducing knock. Water goes into the cylinder mixes then controls the burn and incylinder temps up to 60*! Water will easly remove more heat than meth in turn reducing knock. All this to Allow you to advance the timing, leaning it out and uping the boost = more power.
Good luck!
Evan Smith
Or are you just calling detonation "predet"?
Last edited by mplspilot; Oct 29, 2008 at 02:37 PM.
Oct 29, 2008, 02:44 PM
#50
Higher octane's main exsistance is to have improved resistance to detonation.
Deflageration is the rate at which the burn in the cyclinder is moving, high octane has little to no effect on this burn. Its all to common of a myth that higher octane "burns slower" its not true. Just less prone to detonation.
Oct 29, 2008, 03:13 PM
#51
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I love how Vivid is so polite....I always hear people explaining the theory from different viewpoints, and this is the first I have heard it put the way he is saying it.
Oct 29, 2008, 03:13 PM
#52
Rally cars use 100% H20 because the rules force them to use the same 'fuel' but straight water fits in their rules (from what I have been told by a few rally people). I have run 100% water, 50/50 and straight meth and I certainly have more hp and reistance to knock with 100% meth. Meth obviously has less cooling effect than water but it has enough, combined with its natural resistance to knock seemed to yield better results for me. I don't want us to stray off topic and muddy up this thread so I will refrain from us getting into too much debate here. Thanks for your input.
Last edited by Jack_of_Trades; Oct 29, 2008 at 03:21 PM.
Oct 29, 2008, 03:20 PM
#53
Im just calling it "predet".
Higher octane's main exsistance is to have improved resistance to detonation.
Deflageration is the rate at which the burn in the cyclinder is moving, high octane has little to no effect on this burn. Its all to common of a myth that higher octane "burns slower" its not true. Just less prone to detonation.
Higher octane's main exsistance is to have improved resistance to detonation.
Deflageration is the rate at which the burn in the cyclinder is moving, high octane has little to no effect on this burn. Its all to common of a myth that higher octane "burns slower" its not true. Just less prone to detonation.
Oct 29, 2008, 03:36 PM
#54
Rally cars use 100% H20 because the rules force them to use the same 'fuel' but straight water fits in their rules (from what I have been told by a few rally people). I have run 100% water, 50/50 and straight meth and I certainly have more hp and reistance to knock with 100% meth. Meth obviously has less cooling effect than water but it has enough, combined with its natural resistance to knock seemed to yield better results for me. I don't want us to stray off topic and muddy up this thread so I will refrain from us getting into too much debate here. Thanks for your input.
Great articel about water injection on rally cars
http://www.i-club.com/forums/showthr...ght=subaru+wrc
Great threads regaurding injection mixtures
https://www.evolutionm.net/forums/sh...hlight=article
https://www.evolutionm.net/forums/sh...d.php?t=372627
Not to digrade your tuning or system but in order to extract more power out of a 50/50 mixture you have to tune for it properly and more importantly the system needs to be set up correctly in order to see gains over 100% meth. Your set up sounds perfect for 100% meth so therefore it works best.
I agree 100% meth is always the more easy of the 3 mixtures to extract more power, but is it the safest for the motor? or most cost effective? I dont think so. Its basicaly tuning a evo with 100 octain early in morning in AZ when its dry and 60 degrees out, easy and very nice!
Respectfully
Evan Smith
Last edited by Vivid Racing; Oct 29, 2008 at 03:48 PM.
Oct 29, 2008, 04:28 PM
#55
I ran water/meth injection in my Eclipse years ago, and didn't mess too much with it, so I can't comment too much on the subject, but there is one thing I remember that sticks in my mind from someone that was heavily into the water/meth injection years ago.
He got his best power from 75/25 meth/water. He tried 100% meth, 50/50, 75/25 and a few others I believe. I forgot all of the details as it was years ago, but maybe try 75/25 meth water and see how it works out.
He got his best power from 75/25 meth/water. He tried 100% meth, 50/50, 75/25 and a few others I believe. I forgot all of the details as it was years ago, but maybe try 75/25 meth water and see how it works out.
Oct 29, 2008, 05:49 PM
#57
If using 50/50 leaner afrs will produce better numbers without the harmfull effects on the bottom end. As the water replaces the several points of fuel that was used for cooling, it ends up producing less harmfull CO. CO will inhibit the combustion much greater than water. The richer afrs you run, the more CO you will produce taking oxygen out of the cylinder, resulting in a power loss.
Evan Smith
Oct 29, 2008, 06:02 PM
#58
I respectfully disagree, mixed meth needs to be richer from what i have seen.
50/50 and 12-12.5:1 AFRs. There are many reasons that this could have happened but it doesnt appear that the valve snapped first. I realise its impossible to say but there is NO piston so I think it probably destroyed itself first.
50/50 and 12-12.5:1 AFRs. There are many reasons that this could have happened but it doesnt appear that the valve snapped first. I realise its impossible to say but there is NO piston so I think it probably destroyed itself first.
Oct 29, 2008, 06:18 PM
#60
BWAHAHAHA...
I didnt do it...just inspected it and are moving onto the next phase
That dark spot in the cylinder wall is actually the waterjacket...not typical scuffing. I will take a better pic now that the motor is out of the car.
p.s. I edited my post that talked about MBT if anyone is interested
I didnt do it...just inspected it and are moving onto the next phase
That dark spot in the cylinder wall is actually the waterjacket...not typical scuffing. I will take a better pic now that the motor is out of the car.
p.s. I edited my post that talked about MBT if anyone is interested