-water Injection-
08-26-2003, 06:00 PM
#1
Senior Member
Thread Starter
Join Date: Jul 2003
Location: in my pants
Posts: 227
I think there needs to be a seperate thread on this, possibly a sticky. also I have been reading up on water injection, and uperently it does wonders for people. Please feel free to post your thought about water injection. Any experience or knowledge is greatly apreciated.
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1. Water injection increases the mass of air/fuel mixture entering the cylinders, because it cools the hot air from the turbo's compressor. As the water droplets hit the compressor wheel going 100,000 rpm or so, a mist of amazingly small droplets is formed. These have such an incredibly large surface area compared to their volume that they evaporate (change to vapor) almost instantly, absorbing a tremendous amount of heat from the air-fuel mixture just before it is compressed and lit. The cooler mixture is denser, so for a given boost pressure, there will be more fuel and oxygen in the cylinder when the intake valve closes.
2. Water injection allows a higher intake manifold pressure before the detonation limit. The torque your engine produces is closely related to manifold pressure. Double the pressure, and at any given RPM, power will be approximately double. This applies only when the pressure is measured as "absolute" rather than the common "gauge" pressure. There are a number of ways to define absolute pressure, the most appropriate for turbos being "Bar". On the Bar scale, 0 is a vacuum, 1 is standard sea-level air pressure, and so on. A naturally-aspirated (non-supercharged or turbocharged) 510 will almost get 1 Bar at the peek torque RPM, while a turbocharged 510 can often exceed 2 Bars with water injection. This corresponds to about 15 PSI boost. Joe Keller of Whittier, CA, has exceeded 3 bars on his very trick L16. This represents about the limit for a single-stage turbo, and required 6:1 compression, aviation gas, and water injection.
By Member David Lewis
(www.510again.com)
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As many of you know, water injection has been used for many years to help suppress detonation on high performance internal combustion engines. It is usually possible to run higher compression ratios, more boost pressure, and further advanced ignition timing on an engine with water injection. With everything else working properly, this should result in more power. Water injection works to increase the effective octane rating of the mixture entering the cylinders. This is accomplished through charge air cooling (water vaporization requires a tremendous amount of energy), and through the "slowing" effect the water vapor has on the combustion process. This helps prevent the uncontrolled combustion that can destroy an engine.
Let me give you a little history behind how I finally arrived at my latest water injection design. About 2 years ago, I decided to experiment with water injection after reading about it. I was fascinated with what some people had done in the past. For example, I believe it was back in the 60's when a guy ran a "low tech" Corvair with dual stock Rajay turbos, propane fuel, and water injection at Bonneville and reached 176 MPH. His turbocharged motor was said to produce over 450HP...with NO intercoolers. The simplicity and potential of water injection really appealed to me.
CHARGE AIR TEMPERATURE DATA
TEMP(F) W/O H20.................TEMP(F) W/H20
316.9....................................170.4
326.0....................................168.9
324.3....................................168.9
322.3....................................170.8
317.6....................................185.9
317.0....................................150.7
320.8....................................173.8
320.0....................................170.9
I was very surprised at the tremendous temperature drop caused by the water injection. It dropped the temperature 150F!! This is more than the average temperature drop in my air/water IC system! H20 injection is a very economical intercooling solution. Total cost of my system was probably around $80 or so. This is a real bargain considering the tremendous "intercooling" effect of the water.
Unfortunately, the laws of thermodynamics will not permit the 150F temp drop for the H20 injection and 146F temp drop through the IC to collectively add. Too bad...air temp drop would be near 300F...with charge air temp approaching 0F...80 F below ambient air temperature! Brrrrrrrrrr! The actual charge air temp drop for the water injection and intercooling combined is a little over 190F.
Some brief parting notes, it is very important to have a solid ignition system to enable the spark plugs to fire in the water vapor filled mixture. I replaced cap, rotor, plug wires, & spark plugs. I gapped the plugs a little smaller (around .028) to make it easier for the spark to jump during high boost conditions. Tuning up the ignition system made a noticeable improvement in power delivery - the engine accelerated more smoothly.
Water injection...proof that simple ideas can be very effective!
(http://home.ccci.org/Key_Information...rInjection.htm)
Some of the mods on that car
(visit http://home.ccci.org/Key_Information/MerkurPage.htm for more info):
Ported Big Valve Cylinder Head
Turbonetics T3/T04E Hybrid Turbo
SuperCoupe Air/Air Intercooler Installation
Big 60mm Throttle Body
Ported Intake & Exhaust Manifolds
K&N Cone Filter in cold air plenum
Hi Flow Exhaust - 3" Mandrel Bent DP, 3" CAT, Magna Flow Muffler (3" IN, DUAL 2.5" OUT)
Boost set at 20psi
Bosch Bypass Valve
45pph flow matched Bosch injectors
Walbro Hi-Pressure 255lph Fuel Pump
EEC Tuner
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I must say this is quite impressive. Did I mention this cost $80!! The only "expensive" components were the pump and the nozle, both at under 80$. For this kind of result, this really a worthy upgrade.
There are poepe on http://www.homemadeturbo.com who run at over 1000+ hp and are VERY pleased with water injection.
There is also has been experementation with injecting water directly in to the turbo. Test show that as long as the water is atomized in to a fine mist before it enters the turbo, the blades take no wear and preformance soars.
-----------------------------------------------------------------------------
Wonderful Sticky on homemadeturbo.com
http://www.homemadeturbo.com/forum/i...d=4257;start=0
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some great links:
http://home.ccci.org/Key_Information...rInjection.htm
http://www.dawesdevices.com/howto.html
http://www.510again.com/articles/wat.../watering.html
-----------------------------------------------------------------------------
1. Water injection increases the mass of air/fuel mixture entering the cylinders, because it cools the hot air from the turbo's compressor. As the water droplets hit the compressor wheel going 100,000 rpm or so, a mist of amazingly small droplets is formed. These have such an incredibly large surface area compared to their volume that they evaporate (change to vapor) almost instantly, absorbing a tremendous amount of heat from the air-fuel mixture just before it is compressed and lit. The cooler mixture is denser, so for a given boost pressure, there will be more fuel and oxygen in the cylinder when the intake valve closes.
2. Water injection allows a higher intake manifold pressure before the detonation limit. The torque your engine produces is closely related to manifold pressure. Double the pressure, and at any given RPM, power will be approximately double. This applies only when the pressure is measured as "absolute" rather than the common "gauge" pressure. There are a number of ways to define absolute pressure, the most appropriate for turbos being "Bar". On the Bar scale, 0 is a vacuum, 1 is standard sea-level air pressure, and so on. A naturally-aspirated (non-supercharged or turbocharged) 510 will almost get 1 Bar at the peek torque RPM, while a turbocharged 510 can often exceed 2 Bars with water injection. This corresponds to about 15 PSI boost. Joe Keller of Whittier, CA, has exceeded 3 bars on his very trick L16. This represents about the limit for a single-stage turbo, and required 6:1 compression, aviation gas, and water injection.
By Member David Lewis
(www.510again.com)
-----------------------------------------------------------------------------
As many of you know, water injection has been used for many years to help suppress detonation on high performance internal combustion engines. It is usually possible to run higher compression ratios, more boost pressure, and further advanced ignition timing on an engine with water injection. With everything else working properly, this should result in more power. Water injection works to increase the effective octane rating of the mixture entering the cylinders. This is accomplished through charge air cooling (water vaporization requires a tremendous amount of energy), and through the "slowing" effect the water vapor has on the combustion process. This helps prevent the uncontrolled combustion that can destroy an engine.
Let me give you a little history behind how I finally arrived at my latest water injection design. About 2 years ago, I decided to experiment with water injection after reading about it. I was fascinated with what some people had done in the past. For example, I believe it was back in the 60's when a guy ran a "low tech" Corvair with dual stock Rajay turbos, propane fuel, and water injection at Bonneville and reached 176 MPH. His turbocharged motor was said to produce over 450HP...with NO intercoolers. The simplicity and potential of water injection really appealed to me.
CHARGE AIR TEMPERATURE DATA
TEMP(F) W/O H20.................TEMP(F) W/H20
316.9....................................170.4
326.0....................................168.9
324.3....................................168.9
322.3....................................170.8
317.6....................................185.9
317.0....................................150.7
320.8....................................173.8
320.0....................................170.9
I was very surprised at the tremendous temperature drop caused by the water injection. It dropped the temperature 150F!! This is more than the average temperature drop in my air/water IC system! H20 injection is a very economical intercooling solution. Total cost of my system was probably around $80 or so. This is a real bargain considering the tremendous "intercooling" effect of the water.
Unfortunately, the laws of thermodynamics will not permit the 150F temp drop for the H20 injection and 146F temp drop through the IC to collectively add. Too bad...air temp drop would be near 300F...with charge air temp approaching 0F...80 F below ambient air temperature! Brrrrrrrrrr! The actual charge air temp drop for the water injection and intercooling combined is a little over 190F.
Some brief parting notes, it is very important to have a solid ignition system to enable the spark plugs to fire in the water vapor filled mixture. I replaced cap, rotor, plug wires, & spark plugs. I gapped the plugs a little smaller (around .028) to make it easier for the spark to jump during high boost conditions. Tuning up the ignition system made a noticeable improvement in power delivery - the engine accelerated more smoothly.
Water injection...proof that simple ideas can be very effective!
(http://home.ccci.org/Key_Information...rInjection.htm)
Some of the mods on that car
(visit http://home.ccci.org/Key_Information/MerkurPage.htm for more info):
Ported Big Valve Cylinder Head
Turbonetics T3/T04E Hybrid Turbo
SuperCoupe Air/Air Intercooler Installation
Big 60mm Throttle Body
Ported Intake & Exhaust Manifolds
K&N Cone Filter in cold air plenum
Hi Flow Exhaust - 3" Mandrel Bent DP, 3" CAT, Magna Flow Muffler (3" IN, DUAL 2.5" OUT)
Boost set at 20psi
Bosch Bypass Valve
45pph flow matched Bosch injectors
Walbro Hi-Pressure 255lph Fuel Pump
EEC Tuner
-----------------------------------------------------------------------------
I must say this is quite impressive. Did I mention this cost $80!! The only "expensive" components were the pump and the nozle, both at under 80$. For this kind of result, this really a worthy upgrade.
There are poepe on http://www.homemadeturbo.com who run at over 1000+ hp and are VERY pleased with water injection.
There is also has been experementation with injecting water directly in to the turbo. Test show that as long as the water is atomized in to a fine mist before it enters the turbo, the blades take no wear and preformance soars.
-----------------------------------------------------------------------------
Wonderful Sticky on homemadeturbo.com
http://www.homemadeturbo.com/forum/i...d=4257;start=0
-----------------------------------------------------------------------------
some great links:
http://home.ccci.org/Key_Information...rInjection.htm
http://www.dawesdevices.com/howto.html
http://www.510again.com/articles/wat.../watering.html
08-26-2003, 06:19 PM
#2
Senior Member
Thread Starter
Join Date: Jul 2003
Location: in my pants
Posts: 227
There is also has been experementation with injecting water directly in to the turbo. Test show that as long as the water is atomized in to a fine mist before it enters the turbo, the blades take no wear and preformance soars.
Do not spay directly in to turbo if you are using water. It will make the housing and parts rust. That ofcoarse IF the water doesnt evaporate imidiatly which it should normaly but better safe then sorry. A guy form aquamist (they make water injection kits) said that it is better not to spray in to the turbo itself. He said the intake mani or the charge pipes right before the t-body ar ethe most ideal spots to mount the water injector.
08-26-2003, 06:35 PM
#3
Senior Member
Thread Starter
Join Date: Jul 2003
Location: in my pants
Posts: 227
a point for all that worry about keep refilling the water tank:
"I am using a Saab intercooler as a reservoir, and managed to thread a screw into one of the drain plugs on the bottom, using that to feed to my pump.
I am not sure how much of it is emptying, but I do know that it doesn't really need to be filled up except every 2 tanks of gas or so. I usually top it off every time I put gas in the car. But I have drove over 600 miles without having pinging, this is also with the boost sensor set to activate at 1 psi."
-Chacko
http://www.homemadeturbo.com
"I am using a Saab intercooler as a reservoir, and managed to thread a screw into one of the drain plugs on the bottom, using that to feed to my pump.
I am not sure how much of it is emptying, but I do know that it doesn't really need to be filled up except every 2 tanks of gas or so. I usually top it off every time I put gas in the car. But I have drove over 600 miles without having pinging, this is also with the boost sensor set to activate at 1 psi."
-Chacko
http://www.homemadeturbo.com
08-27-2003, 02:33 AM
#6
Member
Join Date: Jul 2003
Location: Planet Cusco...
Posts: 53
Have a look around the main Aquamist (makers of water injection kits). There is plenty of good information on here, sadly not much relating to rotarys, but I am looking to change that as I will be speaking to him very soon about upgrading my install. 
Dan
Dan
08-27-2003, 06:42 PM
#8
Senior Member
Thread Starter
Join Date: Jul 2003
Location: in my pants
Posts: 227
someone in another thread asked if this requires a seperate tank for water. Yes and no. You can use your windshield wash fluid tank for this or mount a seperate one.
I was thinking and realized:
1. with water injection there is no need for the intercooler
2. if no need for intercooler the why not remove it, and cut down the lag
3. !IDEA! why not KEEP the intercooler, but use it as a container for water (or whatever your mixture is). Basicaly like a radiator. Kepp the water that will be injected nice and cool. Hence helping wi to be mor effective.
I was thinking and realized:
1. with water injection there is no need for the intercooler
2. if no need for intercooler the why not remove it, and cut down the lag
3. !IDEA! why not KEEP the intercooler, but use it as a container for water (or whatever your mixture is). Basicaly like a radiator. Kepp the water that will be injected nice and cool. Hence helping wi to be mor effective.
08-27-2003, 07:29 PM
#9
Senior Member
Join Date: Dec 2002
Location: fredneck MD
Posts: 4,107
i dont think just using waterinjection will illevate the need for an intercooler. Water injection operates under boost. The air is still going to be hot without the water injection!
What are your goals for the car?? Are you going to drive it on the street?
What are your goals for the car?? Are you going to drive it on the street?
08-28-2003, 12:56 AM
#10
Senior Member
Thread Starter
Join Date: Jul 2003
Location: in my pants
Posts: 227
The air is still going to be hot without the water injection!
WFT?????! I am lost. What are you trying to say? ofcoarse it will be hot without water injection. Thats why you get water injection, to cool off the air. And yes it does eliminate the need for the intercooler. A few people on http://www.homemadeturbo.com have done water injection and said that there is no need for the intercooler.