I don't think the water does anything to prevent detonation, other than the evaporative cooling, which Methanol does way better. Just because the water itself doesn't detonate doesn't mean it does anything to chemically prevent detonation of the fuel.
I'd have to disagree, octane by definition is how much fuel can be compressed before it spontaneously ignites, by adding water you are obviously lowering it's chance to ignite from compression at X compression. In WWII they added soley water to airplane engines and it significantly reduced knock.
At least in my logic it works, I learned a lot about meth/water injection from a big local turbo Buick guy, who also is in weapons development, super smart guy. But I guess he could be mistaken.
__________________
2000 A4 WS6 Trans Am 396ci - D1-SC - Stalled Auto - 3966lb - 808.65 RWHP 729.95 RWTQ - 9.98 at 130 MPH SOLD 11/09 2001 A4 Trans Am H/C - Stalled Auto - 3650lb - 442 RWHP 403 RWTQ - 11.6 @ 117 MPH (hitting the limiter) SOLD 1998 A4 Trans Am Very mild H/C - Stalled Auto - 3550lb - 396 RWHP 390 RWTQ - 12.0 @ 113 MPH SOLD
I'd have to disagree, octane by definition is how much fuel can be compressed before it spontaneously ignites, by adding water you are obviously lowering it's chance to ignite from compression at X compression. In WWII they added soley water to airplane engines and it significantly reduced knock.
It reduces knock just due to the evaporative cooling, not the so-called octane rating. You can't put an octane rating on water. It's like saying that torque has a color.
__________________ 1995 Z28
388 LT4, AFR 210's, Home built T-76GTS turbo system
TH-350, Vigilante 10.5", Ford 9"
It reduces knock just due to the evaporative cooling, not the so-called octane rating. You can't put an octane rating on water. It's like saying that torque has a color.
i always thought water injection was used to slow the flame fornt down? this reduce the chance of dept. happening, effectively raising the octane rating of the mix..... no?
i was always led to believe that water has NO - VERY little cooling effect (esp compeard to meth) and should not be used to reduce intake temps.
its a bim like trying to burn dry paper and then slighty wet paper, the dry paper will burn faster. Same inside the engine. what is basically happening is the water is absorbing some of the thermal energy created by the burning fuel and air. this slows the burn down. if you injected enough water it would put the flame out totaly!
WRC rally car have been using this more MANY years now. small amounts of water are injected into each cylinder. they actually map the water injection and very it slightly to each cyclinder to ensure they are getting the most out of the engines.
its a bim like trying to burn dry paper and then slighty wet paper, the dry paper will burn faster. Same inside the engine. what is basically happening is the water is absorbing some of the thermal energy created by the burning fuel and air. this slows the burn down. if you injected enough water it would put the flame out totaly!
The water doesn't cool the IAT's down much in the intake manifold because it doesn't evaporate as readily as Meth. However, once in the chamber, it basically takes heat out of the combustion process which does slow it down and reduce detonation. However, most of the guys who run big boost (DSM guys running 45+ psi) run straight Meth with a 50+% replacement. I'd venture to say you can't do that with water.
__________________ 1995 Z28
388 LT4, AFR 210's, Home built T-76GTS turbo system
TH-350, Vigilante 10.5", Ford 9"
The water doesn't cool the IAT's down much in the intake manifold because it doesn't evaporate as readily as Meth. However, once in the chamber, it basically takes heat out of the combustion process which does slow it down and reduce detonation. However, most of the guys who run big boost (DSM guys running 45+ psi) run straight Meth with a 50+% replacement. I'd venture to say you can't do that with water.
Mike you are right, but with a 50%+ replacement of meth you are pretty much using the meth as a fuel as apposend to be an additive...
It would be nice to see someone that uses meth to reduce temps (ie just getting the meth to evap. and pull temps down), then spraying water direct into ports (to help push the dept. threshold higher) and then race fuel, C16, for the body of the fueling demands. That should net a perrty potent setup on any platform!
Aslo is there any other readily avaliable chems that could be used to help reduce temps over and above meth? obviously the cooling efect of meth will stop once the air in saturated with meth. So by using another chem. intake temps could be reduced further still.....
I can tell you meth with C16 doesnt work for me. It cools the IATS too much and just wontlet the c16 light off. Now i dont necessarily need c16....just use it for extra protection like wearing 3 condoms Once i remove the meth the power comes back on c16. Now meth did work on sunoco maximal for me but the reid vapor pressure is way higher on maximal vs c16. c16 likes the heat!!!
maximal is like 6.x rvp where c16 is like 2.x rvp
__________________ 9.29 @ 150 at 14psi
3960# raceweight
OFI s488
Transformance 4l80 with rossler tbrake
408 with etp heads
3.08 rear
Yank PY3400 stall
Bmr everything
well, chemically speaking, i would say that mixing gas with water would in fact raise the ignition temperature of the gas mixture and keep det. to a minimum. diluting the fuel with water would technically reduce the number of hydrocarbons in the mixture, meaning that it takes more heat for combustion to occur. meth cools better, but ignites faster than water.
__________________
250 RWHP - Ferrari Killer!!!
99 Sierra Custom - Stock 5.3L 15.2@89
Quote:
Originally Posted by 2002_Z28_Six_Speed
I don't add people I don't know unless they are loosely related to me or they have big ass titties.
Ah yes... another never ending meth vs meth/water mix thread...
Before I throw in my .02 cents, I will say to the original question, that 93+ meth injection will do an almost duplication of Race gas (but obviously for much cheeper).
But back to the thread that has become; this isn't anything new. And to my knowledge no one has proven one way or the either which is more benefitial between running straight meth and water/meth mix.
I have personally seen a decrease in IAT's from running the water/meth mix vs straight meth. Combine that with the fact that straight meth is more corrosive, and that is why I choose to go the water/meth mix way over straight methanol.
Some companies like Alky-Control argue that "you must run straight meth", while others like Snow Performance argue, "best performance can be attained with water meth mix".
Either way will work. I believe if you want the added octane, go straight meth. If you want to cool things more to keep from detonation, go with the water meth mix.
__________________ 98 Formula WS6 M6, MS3, 2.5 5.3 heads, FAST 92mm intake, 92mm TB, ARH, ORY ect. 441 RWHP 95 Z28 M6, 383, D1SC, FMIC, pump gas with the stock PCM 614 RWHP
Ah yes... another never ending meth vs meth/water mix thread...
Before I throw in my .02 cents, I will say to the original question, that 93+ meth injection will do an almost duplication of Race gas (but obviously for much cheeper).
But back to the thread that has become; this isn't anything new. And to my knowledge no one has proven one way or the either which is more benefitial between running straight meth and water/meth mix.
I have personally seen a decrease in IAT's from running the water/meth mix vs straight meth. Combine that with the fact that straight meth is more corrosive, and that is why I choose to go the water/meth mix way over straight methanol.
Some companies like Alky-Control argue that "you must run straight meth", while others like Snow Performance argue, "best performance can be attained with water meth mix".
Either way will work. I believe if you want the added octane, go straight meth. If you want to cool things more to keep from detonation, go with the water meth mix.
THAT right there answers my original intended question, I guess I just worded it poorly. Thanks
__________________
2000 A4 WS6 Trans Am 396ci - D1-SC - Stalled Auto - 3966lb - 808.65 RWHP 729.95 RWTQ - 9.98 at 130 MPH SOLD 11/09 2001 A4 Trans Am H/C - Stalled Auto - 3650lb - 442 RWHP 403 RWTQ - 11.6 @ 117 MPH (hitting the limiter) SOLD 1998 A4 Trans Am Very mild H/C - Stalled Auto - 3550lb - 396 RWHP 390 RWTQ - 12.0 @ 113 MPH SOLD
Ah yes... another never ending meth vs meth/water mix thread...
Before I throw in my .02 cents, I will say to the original question, that 93+ meth injection will do an almost duplication of Race gas (but obviously for much cheeper).
But back to the thread that has become; this isn't anything new. And to my knowledge no one has proven one way or the either which is more benefitial between running straight meth and water/meth mix.
I have personally seen a decrease in IAT's from running the water/meth mix vs straight meth. Combine that with the fact that straight meth is more corrosive, and that is why I choose to go the water/meth mix way over straight methanol.
Some companies like Alky-Control argue that "you must run straight meth", while others like Snow Performance argue, "best performance can be attained with water meth mix".
Either way will work. I believe if you want the added octane, go straight meth. If you want to cool things more to keep from detonation, go with the water meth mix.
and THAT right there answers mine close enough without the real world comparison in numbers. thanks.
i think i just peed a little 
Once i remove the meth the power comes back on c16. Now meth did work on sunoco maximal for me but the reid vapor pressure is way higher on maximal vs c16. c16 likes the heat!!!
