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-   -   Water Injection (https://www.rx7club.com/single-turbo-rx-7s-23/water-injection-32303/)

LUV94RX7 12-14-02 03:54 PM


Originally posted by 94SR2
Dave @ KDR tuned car with water.
If that's a question to me, then the answer is YES.

Ken

LUV94RX7 12-15-02 09:44 AM

Maybe it's time Jason of the RX-7 store add Aquamist to his product offerings. Maybe start out with a group buy.

I know of no one who regretted using water injection. I love mine. Everytime I add water to my 3 gallon fuel cell it makes me feel good. I know I prevented detonation.

Ken

DavidV 12-15-02 11:37 AM


Originally posted by LUV94RX7
Maybe it's time Jason of the RX-7 store add Aquamist to his product offerings. Maybe start out with a group buy.
Sounds like a great idea. Please have Jason get in touch with me. I would be happy to set up his account with some very favorable pricing.

-- DavidV :D

LUV94RX7 12-16-02 10:13 AM

I did a run today using the Omega air temp probes. They are located in the K&N air filter, just before the IC, just after the IC and about a foot after the water injector. That probe is about one foot before the throttle body.
The run was from 40-70+(4-7.5+ rpms). Max boost was 15psi.
Outside temp was 22F.
Max in K&N filter was 71F.
Max after turbo was 231F.
Max after IC was 85F.
Max at probe after water injection was 61F.
I don’t know where the Commander air temp probe is, I’m guessing just before the air goes into the engine, as its max was 88F.

These tests will be more helpful in the summer. Today the IC had 22F air going through it at 70mph. When the IC has 90F going through it there is no way it can drop it from 231F to 85F. I think water will be more valuable in summer weather.

As I said before I installed water to prevent detonation. Our beloved rotaries blow up mainly due to detonation and over heating. The benefits of cooler air intake temps, cooler combustion chamber and cleaner combustion chamber are just bonuses.

Ken

LUV94RX7 12-16-02 12:27 PM

Be prepared to use a lot of water. My system kicks in at 7psi and 3k rpms. The volume of water increases as the rpms and boost increase. I'm glad I have the 3-gallon fuel cell. I just used 2 gallons of water in 80 miles of spirited driving.

I'd like to see DavidV give us some stats on the decreased EGTs with and without water. If it cools the combustion chamber then the EGT should be reduced.

Ken

fastrotaries 12-16-02 02:38 PM

i was thinking of using mine @ 4k + and 8 psi. I think with water you can get away with a little more than with out it. Summer in West Texas and Fl are hard on high boosted rotaries.

ken: I assume you use demineralized water, but how much do you mix to keep it from freezing. I was thinking 8% nitromethane or Methanol. But i can't seem to get my math right for the proper ratio. What do you use?

LUV94RX7 12-16-02 02:44 PM

I use windshield washer stuff I buy at the store that uses methanol and mix it with water. The stuff is is good for -25F and I just guess on the mixture ratio. I bought a reverse osmosis water purifier so I can make sure the water is 100% pure(no contaminments).

Ken

rallimike 12-16-02 03:04 PM

There is a GReddy elbow with a spot for fuel injectors; can that be used for the Aquamist injection. Anyone know?

nocab72 12-16-02 03:42 PM

I don't see why not. Is certainly a convienent setup.

vosko 12-16-02 03:47 PM

that's a damn good idea for my greddy elbow injector holes... hmmm interesting

fastrotaries 12-17-02 12:23 AM

Wow reverse osmosis, you're not fucking around Ken. i never thought about windshield washer fluid. In reality i don't think the water would matter if it was potable as long as it doesn't contain mineral deposits. do you have a Shaklee Osmosis water purifier? I'm a water professional, so i'm just curious.

RICE RACING 12-17-02 01:37 AM

I run my water through my Water Purifier first too :D Does not sound as good as Kens though :confused:

LUV94RX7 12-17-02 06:52 AM


Originally posted by fastrotaries
Wow reverse osmosis, you're not fucking around Ken. i never thought about windshield washer fluid. In reality i don't think the water would matter if it was potable as long as it doesn't contain mineral deposits. do you have a Shaklee Osmosis water purifier? I'm a water professional, so i'm just curious.
Yes, I've had it for ten years. All I did was buy new filters for it. It makes great drinking water. Will never clog my water injectors.

There are different kinds of windshield washer fluid, I get the ones that use methanol.

Ken

LUV94RX7 12-17-02 07:27 AM

This was posted on the MR2 board. A Syclone had decreased EGT of 40C with water on compared to water off. I'm guessing it will be much greater on a 15/22psi boosted turbo rotary. They run very very hot.

Maybe I should get an EGT gauge.

Ken

LUV94RX7 12-17-02 07:38 AM

All these threads on V8 conversions are interesting. They are nailing the rotary's reliability and lack of low end torque. My car has 330lb of torque at 5k rpms at 15psi. Not bad for a rotary. In 5th gear I floor it and I have 5psi boost at 2.5k rpms, 10 psi at 3k rpms and 15psi at 3.5k rpms. That's not too bad. Now if water saves my motor then a V8 conversion is not as advantageous. The V8 guys have lots of good points though. My nephew has a Chev V8 FC and it is rock solid.

I guess I am pushing water because Dave at KDR says with water my motor should be bullet-proof. If I get 50k miles out of the motor with spirited driving at 15/22psi I will be very pleased. I'm tired of seeing all our beloved rotaries being blown up by detonation. I went through one motor due to detonation. No more of that crap, I hope.

Ken

Marcel Burkett 12-17-02 11:08 AM

I am using Demineralized water which I get at work ,(made at the demin. plant for plant needs) this is essentially ultra pure water where all the dissolved anions and cations are removed . I then stroll over to the methanol sample point (pure distilled methanol) where I extract my bounty in a 1 litre bottle and mix a 50/50 mixture and put it in my H2O inject. reservoir.

fastrotaries 12-20-02 01:19 AM

i would think that 50/50 h20 meth mix is a bit steep, how do you feel it affects your timing and general tuning?

Ken: are you running your boost settings with pump gas? because i would find that impressive. i really think that water is the way to go. my issue is where to place the tank, and decide on a size.

Marcel Burkett 12-20-02 03:26 AM

50/50 is the max. recomended ratio , I might go a bit lower though , still need to test and tune it.

LUV94RX7 12-20-02 05:55 AM


Originally posted by fastrotaries i would think that 50/50 h20 meth mix is a bit steep, how do you feel it affects your timing and general tuning?
Ken: are you running your boost settings with pump gas? because i would find that impressive. i really think that water is the way to go. my issue is where to place the tank, and decide on a size.

I will use pure water in the summer, but in the winter here in MN you need some methanol mixed in so it does not freeze. I'm running pump gas at 15psi. KDR said run 100 octane at 22psi. This site has pics of my install and 3 gallon fuel cell for the water.

http://flathat.woodstream.net/LUV94RX7/

Ken

fastrotaries 12-23-02 02:55 AM

Wow clean install. How long does that water tank, Vs gas tank last you. 1:1 gas to water, or more gas tanks per tank of water.

surfpac 12-23-02 09:24 AM

Use windshield washer fluid. It has methanol (methyl alcohol) in it and csome other chemicals that lubricate rubber seals, etc. Not sure of the % methanol but you could add a bit of ethanol to the mixture. You can get this from Home Depot in the paint dept under the name denatured alcohol.
I'm making up my own water/alcolhol setup using agricultural pump (60 psi), cold start injector, digital pressure switch, variable DC motor controller (to control flow rate), filter, relays, etc.

fastrotaries 12-24-02 03:33 AM

don't you need a real high psi to properly atomize the water under high boost applications. It's just some of the homework that i've found out.

80-CU.IN.T 12-25-02 12:34 AM

With mixtures of over 20% methanol to H20, the fluids start to separate. Over saturation. I had a very though lecture when I started to play with H20 injection. ( 1986 ) Things have come along way in regards to nozzles and supply methods but I don't think the chemistry has changed.

fastrotaries 12-25-02 03:56 AM

the chemistry shouldn't change, but i thought that the purer the water the less of a chance of that seperation happening. I'll have to look into my books and pull out some more detailed info.

peejay 12-27-02 07:26 PM

I'd imagine you'd want to run the lowest amount of methanol to prevent freezing. The water acts as an anti-detonant in the combustion chamber. Methanol, however, is a fuel, and can contribute to detonation.

if the car never sees below freezing temps, why not just run pure water?


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