Cheap water injection source
01-06-2005, 07:20 PM
#16
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" Order $1,000 worth of our Deluxe or Single stage kits and You will receive 25 pct off retail."
So a group buy would be real cheap.
So a group buy would be real cheap.
01-06-2005, 07:29 PM
#18
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Yea, but that is for dealer pricing. I figure 5-7 kits, depending on which kit, would get 1,000 in orders and thus a 25% discount.
01-06-2005, 07:44 PM
#20
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I am a little sceptical about water injection after stripping a few engines down that had it fitted.
I found that the plenum areas seemed unusually highly pitted. Yes it does work well in practice but is it worth it on a road car? Remember Audi fitted it on a few road cars some years ago and ended up removing it very quickly. The Ford GT40's of the late 1960's had a steam injection system for a short time but again it was removed after a season or so. I need somebody to convince me on this one.........
I found that the plenum areas seemed unusually highly pitted. Yes it does work well in practice but is it worth it on a road car? Remember Audi fitted it on a few road cars some years ago and ended up removing it very quickly. The Ford GT40's of the late 1960's had a steam injection system for a short time but again it was removed after a season or so. I need somebody to convince me on this one.........
01-06-2005, 07:47 PM
#21
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Tommo,
That would not so apply to port injection though, and if the mist is fine enough (atomosied) then all should be well, dont you think? Oter than this pitting which may be avoided in PWI (port water injection) then were there other issues you can think of?
That would not so apply to port injection though, and if the mist is fine enough (atomosied) then all should be well, dont you think? Oter than this pitting which may be avoided in PWI (port water injection) then were there other issues you can think of?
01-06-2005, 08:35 PM
#22
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Port water injection is NOT the best.
H2O does its best work if it enters the cylinders in vapor form. Only then will it achieve the best COMBINATION of density increase (power) and anti-detonation properties. With port injection the water doesn't have enough time to evaporate and raw water enters the cylinders. The flame front slows down too much and the energy developed by the burning fuel is used partially to evaporate the remaining water droplets instead of pushing the piston down. Yes, of course, no detonation, but big deal.
This is only good for people who like to brag about how much boost they can run without detonation, while their race gas buddies blow by them.
To make this evaporation easier, the highest pressure possible should be used because then the water droplets are already small. 60 psi doesn't really cut it because you have to remember there's probably 20 psi boost pressure against it (net result of 40 psi at the nozzle).
The Aquamist pump is good because it's the one pump that can consistantly push high pressure up against small nozzles. Other pumps can flow more, but when the nozzles get too small, these pumps go into some sort of recirculation mode to keep them from stalling and burning out. So, the so-called high pressure actually gets reduced at the nozzle.
But yes, the aquamist pump has issues with high flows and more than 40 to 50 % methanol.
There is a reason for concern with uneven distribution of water with a single nozzle application, but this is mostly due to too high a water usage or bad nozzle location and/or pressure. Then port injection would be better. But then at least try to get very small nozzles and very high pressure.
H2O does its best work if it enters the cylinders in vapor form. Only then will it achieve the best COMBINATION of density increase (power) and anti-detonation properties. With port injection the water doesn't have enough time to evaporate and raw water enters the cylinders. The flame front slows down too much and the energy developed by the burning fuel is used partially to evaporate the remaining water droplets instead of pushing the piston down. Yes, of course, no detonation, but big deal.
This is only good for people who like to brag about how much boost they can run without detonation, while their race gas buddies blow by them.
To make this evaporation easier, the highest pressure possible should be used because then the water droplets are already small. 60 psi doesn't really cut it because you have to remember there's probably 20 psi boost pressure against it (net result of 40 psi at the nozzle).
The Aquamist pump is good because it's the one pump that can consistantly push high pressure up against small nozzles. Other pumps can flow more, but when the nozzles get too small, these pumps go into some sort of recirculation mode to keep them from stalling and burning out. So, the so-called high pressure actually gets reduced at the nozzle.
But yes, the aquamist pump has issues with high flows and more than 40 to 50 % methanol.
There is a reason for concern with uneven distribution of water with a single nozzle application, but this is mostly due to too high a water usage or bad nozzle location and/or pressure. Then port injection would be better. But then at least try to get very small nozzles and very high pressure.
01-06-2005, 09:06 PM
#24
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Wasn't John http://www.vitesseracing.com is making one (water inject) that
wks with the SMT6 ?
Regards
Ed
wks with the SMT6 ?
Regards
Ed
01-06-2005, 10:24 PM
#25
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I think he has already made it, but not many have the SMT6, a more generic one like snow or aquamist at least can be made to fit most configurations. Good that he offers it for those with it though. I wonder if John has some scientific information on where to place the nozzle and why not port injection...
01-07-2005, 08:42 AM
#27
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TurboTommy, my research has turned up the same information on port injection. I would have posted it, but I couldn't find my source and I have no direct experience. There are some obvious benefits to port injection, but its downside far outweighs its advantages. The atomization of water is vital from what I understand and that is very difficult with port.
The primary disadvantage to injecting before the TB is that you may get uneven cylinder distribution. I would guess the distribution would be equal to the air distribution that each cylinder sees which is what is important IMO.
Ultimately, the fabrication cost and additional complexity combined with the difficulty in achieving atomization make port injection less desirable. At least that is my opinion. If you can accept the cost and difficulty along with ensuring atomization it might be attractive. Even then I have seen no evidence of performance or efficiency gains, but they may exist.
Tommo, could you show us some evidence of the pitting you mention or a more in-depth description? This could be very interesting as I have never heard of an issue such as this. As far as why Audi and other production cars stopped using WI, my understanding is that the risk of their customers not filling the reservoir made the system ineffective since the pumps would die and the engine could not be tuned to take advantage of it. I think keeping the layperson limited to one constantly consumable fluid is smart. Most people don't keep their coolant, oil, and brake fluid topped off and some actually run out of gas!
I think that the reliability of pump technology has corrected these initial issues but they are not appropriate in a production car. You will notice that in an effort to mimic their WRC car, the Subaru STi includes intercooler misting but not WI. IC misting is OK, but really only battles heatsoak. It is a marketing attempt to provide something close to their race cars.
Max
The primary disadvantage to injecting before the TB is that you may get uneven cylinder distribution. I would guess the distribution would be equal to the air distribution that each cylinder sees which is what is important IMO.
Ultimately, the fabrication cost and additional complexity combined with the difficulty in achieving atomization make port injection less desirable. At least that is my opinion. If you can accept the cost and difficulty along with ensuring atomization it might be attractive. Even then I have seen no evidence of performance or efficiency gains, but they may exist.
Tommo, could you show us some evidence of the pitting you mention or a more in-depth description? This could be very interesting as I have never heard of an issue such as this. As far as why Audi and other production cars stopped using WI, my understanding is that the risk of their customers not filling the reservoir made the system ineffective since the pumps would die and the engine could not be tuned to take advantage of it. I think keeping the layperson limited to one constantly consumable fluid is smart. Most people don't keep their coolant, oil, and brake fluid topped off and some actually run out of gas!
I think that the reliability of pump technology has corrected these initial issues but they are not appropriate in a production car. You will notice that in an effort to mimic their WRC car, the Subaru STi includes intercooler misting but not WI. IC misting is OK, but really only battles heatsoak. It is a marketing attempt to provide something close to their race cars.
Max
01-07-2005, 11:42 AM
#28
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"With port injection the water doesn't have enough time to evaporate and raw water enters the cylinders."
Not of the injection is "tuned".
The pitting is due to improper atomization of the injection charge. As I stated above, gotta have a good pump and good nozzle.
"60 psi doesn't really cut it because you have to remember there's probably 20 psi boost pressure against it (net result of 40 psi at the nozzle)."
If you are injecting against the flow, i.e. backwards out of the motor or away from the motor, which I have never heard of anyone doing. You inject with or perpendicular to the flow of air.
Not of the injection is "tuned".
The pitting is due to improper atomization of the injection charge. As I stated above, gotta have a good pump and good nozzle.
"60 psi doesn't really cut it because you have to remember there's probably 20 psi boost pressure against it (net result of 40 psi at the nozzle)."
If you are injecting against the flow, i.e. backwards out of the motor or away from the motor, which I have never heard of anyone doing. You inject with or perpendicular to the flow of air.
01-07-2005, 11:49 AM
#29
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Originally Posted by toddk911
If you are injecting against the flow, i.e. backwards out of the motor or away from the motor, which I have never heard of anyone doing. You inject with or perpendicular to the flow of air.
Basically if your intake is pressurized to 15psi above atm and your pump can only pressurize the water to 15psi above atm you will have equilibrium and no flow.
But then again, I could be wrong. Can someone confirm this?
Max