After a week of installing the electric switches, routing the harness into the firewall, then re-doing it when I messed up, making a water tank in my spare tire space and mounting my pump, I finally brought my car in to rx7fashion to have rick tap my elbow and prime the pressure switch.

So I drove it at WOT and the car felt strong, so I went back paid my mechanic and went home on the highway. I was intentionally hitting 8 lbs boost on the highway to inject the water and OMG.....

My Air temps at 6 PM on my way home (about 80 degrees ambient) hit 19C. Thats right 19C. As soon as the water gets injected the temps drop like nasdaq on sept 12. Im pretty happy about this, considering I have a very small Blitz SMIC. After my temps hit 19 I turned the water injection off cause I was a bit nervous. My temps went up to 46 and stabilized.

Its desiged to inject water when it hits the preset boost (8 psi in this case). Once I drop below 8 PSI the water injection stops. I checked my tank when I got home and didn't even use that much water. Maybe a few ounces from my near 2 gallon tank.

Not bad.

 

How much was all this?

 

Lets see:

water pump 60.00
selenoid 25.00
relay 5.00
pressure sw 25.00
switch 2.00
led 2.60
connectors 2.00
15 ft hose 3/8 20.00
brass connectors 15.00
water tank 6.00
spray nozzel 3.00


I did everything myself except tap the elbow and set the pressure switch to activate at 8 lbs boost. So I paid for 1.5 hour labor. It costed about 300 for the entire thing, labor and parts. I estimate I saved $300.00 by mounting the water pump, doing the electric and the harness, etc.

I closely followed this, but I mounted the pump where the Jack goes, and mounted the new water tank in the spare tire location.

http://www.turbomirage.com/water.html


EDIT: I have to thank Marshall, he gave me alot of pointers and helped me out with some basics. Thanks!

 

WOW, defenitly cost effective great mod. Glad to hear you are enjoying it.

 

No problem! Glad its working great. Its an awesome setup, not as bling bling as some but its very effective as you've shown -and more robust than alot of the systems out there.

 

ITS amazing. Mine sprays water right where the elbow ends at the manifold. So as soon as I hit the 8 PSI and hit boost for a few seconds and then lay off the boost, you will watch the temp sensor drop 10 C in just a few seconds. I would not believe it if It didn't happen to me. Running 19C on the highway was crazy. I'm only planning on using the system on really hot days and when I race. During regular driving and really cold winter days I will have the switch off I guess. Thanks again!

 

how about a write up and some pics ?

 

I'll take some pics tomorrow morning of all the parts, showing where they were mounted, etc.

 

That is so damn impressive, David.

In case you guys didn't catch it, those temps were with the smallish Blitz SMIC. I'm really surprised more of the high horsepower guys aren't running this setup. Actually, I'm surprised ALL of the high hp guys aren't running this. David was getting lower intake air temps than the ambient air......

Simply phenomenal!

 

So it's not damaging at all to spray the water in it's raw state into the motor? I might be understanding it wrong, I dunno. Also, wouldn't keeping the water at a certain temperature be important? I don't see how it could stay all that cold riding around in your spare tire well. Please enlighten me as it's something I think I'd like to try

 

There's a really great thread on water injection in the third gen archives that you all should check out. This is one of the first things I'm doing to my R1 after I get back.....along with HIDs .

 

Fantastic technology WI

Hope everyone gets to join the club one day

All the best things in life are free and water proves it once again

 

sounds like a good investment. Not to mention it "cleans" your engines internals. I would think that changing the intake charge by that much would cause you to get your ECU retuned. I may invest in one of these as well in the near future.

 

I prefer not to tune for the WI, as you cant rely on it. If you run out of water or it gets clogged, you can stick a fork in it, its done. Either way, as long as the Air temp sensor recognizes the temp drop in time, your ECU should not need to be retuned. I have a power FC that is pretty well tuned as it is.

Will take pics later today.

 

Wow thats an excellent mod. It great to see 7 owners invest their time into new and better modifications for our cars. Thanks Zerobanger. Can't wait to see pics...

 

here are pics.
https://www.rx7club.com/forum/showth...74#post1935674

 

Nice job! There are many benefits to Water Injection making it a worthwhile safety mod. Old WWII airplanes used it to keep their engines from blowing up when using high amounts of fuel and making bursts of power during takeoff or combat. And of course the lower intake temps is like having a bigger intercooler without the added turbo lag.