Saturated air is slightly less dense than dry air (for a given volume at the same temperature); so one possibility is that total O2 intake has been reduced slightly, resulting in a richer mixture. I haven't done the math at this point, so I'm not sure what percentage of change one might expect to see.

 

TheAsset, as said above, you are likely experiencing O2 dilution due to water vapor "creation".

You need very fine water atomization to minimize this. See my thread at https://www.rx7club.com/auxiliary-injection-173/humidity-o2-dilution-887550/

- Sandro

 

Issue to my problem....AIT table. It was set a little too rich. I'm a noob and didn't even think about it.

 

Turned the boost up, fuel was taken out...still running rich. I've read about o2 dillution, but really can't see that being an issue with ~600cc of water.

So I'm stumped

 

I wouldn't worry about it so much, if the car is running fine and you aren't experiencing breakup just tune it conservatively with the water and you'll be fine. Quick question, what afr's are you running at what boost levels?

 

Right now I'm at 20psi and the AFRs are at 10.2....the issue is, regardless of pulling fuel, it doesn't seem to get any leaner. It does want to break up just a bit around 7800 or in the area but that's understandable being that rich....there is no way I could be diluting the o2 with injection 600cc of water when others are injecting A LOT more.

I also noticed at 15psi the SMIC seems to be doing it's job, when I turned it up to 20psi on the other hand, IAT's will go from 28c up to 46c by the top of a pull...and that's with ambient temps around 15c. I figured water injection and a large SMIC would be sufficient but apparently not?

There is no knock during any of these pulls as they stay in the teens. My main concern is trying to tune for a target AFR with no affects regardless of fuel changes. There is a lot of power and response to be had between 10.1 AFR and a 10.9 AFR

 

Those air temps are fine, water won't be pulling much heat out until it reaches flash point (boiling) You're too rich, pull it out until you hit high 10's or even 11 flat. The water will keep that engine going. Just make sure your system is reliable, you have a water filter and good connections. At 15 psi don't run any richer then 11. Don't worry so much, your safer now at 20 psi then you were before the water at 15 psi.

Edit: wait are you saying when you take fuel from the map the afr's stay the same??

 

ya looks like ima be running all water. BDC is getting to join the pure H20 gang. have m2 pre turbo and m10 post. gonna be running 20 psi on a gt61 turbo.
stock coils n wires. think i will get ignition break up?
using devils own progressive unit with a fmic.

 

Yes fuel gets taken out, and seems to have no affect on AFR...at least nothing consistent

 

Sounds like something with your tuning software rather then anything the water could possibly be causing. Are you saving the changes you make? When logging does it show reduced injector duty? Tuning the correct sells and map?

 

that would be tuning software


yes dont run richer then 11s at 15psi. Killing ignition especially if no cdi.

 

I'm running the HKS DLI...Things seem to be moving in the right direction at least, the car felt a lot better last night. Ill keep this thing updated. If it doesn't rain today I'll be able to get more logs

 

Have you tried another AFR sensor or a second instrument as a double check? worth a try? you could be getting a false reading of what you have?

 

I'm injecting 325cc of windshield wiper fluid (mostly water with a little alcohol) at 20 psi, AFRs in the low 11s, car pulls very hard without a hiccup. My AITs also barely budge on 20 psi pulls, I'm surprised yours are moving that far that quickly.

 

what intercooler setup are you running? Im running the ebay SMIC...the core is a pretty good size but maybe the duct just isn't getting it enough air or it's heat soaking from the radiator. The temps are fine at 15psi when I look at some previous logs, they dont raise near as much. I'm not sure what the limits of an SMIC are

Ive asked a few others and I guess running an 11.3 AFR is a perfectly safe thing to do at 20psi.. looks like I have a lot of room left, the AFR's are slowly getting leaner though. Baby steps.

 

is a 9" filter too long to place a pre turbo nozzle at the very tip?

 

Not if you have room in front of the filter. The distance to the turbo isn't too far if that's what you're asking.

 

no im worrying bout the nozzle spraying and water hitting the air filter instead of being sucked up my turbo since it has to travel 9 inches to turbo in a filter. makes sense?

 

no its not a problem

 

fwiw, if you mounted the tank below the spray nozzle, and then use a simple boost controller (ball and spring) to control the level at which the tank is presurized.

So while its below the predetermined boost level, no boost makes it to the tank, once above a set boost level, the ball and spring rise and allow boost into the tank.

So at the end of it, you have a system that shouldn't drain itself, also its totally mechanical with no electrics to stuff up.


thoughts?

 

im started to get really interested in pre-turbo WI, mostly due to the simplicity.
but more for a safety reason rather then means to increase boost.

i am almost done with my new setup, which will probably push around 400hp on a stock ported 13BT motor at 16psi. (already had 380+ with old FMIC, now went V-mount and a far superior intake routing which should already lower AIT drastic)

not thinking about the nozzle size right now, but i wanted some confirmation on my thoughts.
although, if someone should have an insight on what size to use it would be most appreciated.

if i have my car tuned at 16psi, can i just add WI later on and alter the AIT compensation for this? i will not be raising boost..
I know tuning it with the WI it would be best for results, but then i would have to rely on it to work properly.
reason for this, is IF the WI system should fail or run empty, or i should chose not to run water, i would not grenade my motor instantly..

most important specs regarding this:
stock port 13BT (s5)
BNR stage4 turbo
16bit powerFC

ignition should be up for the job, so breakup won't be an issue (AFR 9.5 has even been no problem)
hks twinpower
FD leading coil
Greddy RE-10 plugs
racingbeat wires

 

Furb, I have the same turbo as you and im running a large streetport, FMIC though. I did the calculations as best i could and concluded i need about 600CC of water for my setup to run around 20PSI safely. So in your case i would say a M15 nozzle should work fine, its slated to put out 500-550 CC.


Also im running the same exact ignition setup as you. Leads, Twin Power. Im not utilizing a FD coil or the 10 plugs, i am however using stock BUREQP's in 9 heat range with AFR's around 10 and have no problems with ignition breakup at 14PSI.

Hope that helps.
BTW your car rocks the ****.

 

Im wondering how you can make this system go over 700cc. The nozzle flows about 750cc max at 2xPSI. How do you get a nozzle flowing 850CC at 2xPSI? make the hole bigger is the obvious but then atomization probably isn't there.

 

Furb you can tune the car to 16 psi (follow safe tuning practices) and then add water injection with no adjustments to anything. As long as your ignition system can handle the extra water you won't have loss of power or ignition breakup. At 16 psi you really don't even need much water. 200-400cc/min would be fine and provide way more protection then running extremely rich.

just startin..... The mechanical system I run and have built for a few others really doesn't need a larger nozzle. At 30 psi it flows nearly 900cc/min with the same atomization as at 20 psi. The amount of cooling taking place with that much water is way more then you could expect by running extremely rich fuel levels. I recently ran my system at 26 psi and 10.9 AFR for a couple of weeks before I had to turn it back down to keep from completely frying my 6 puck clutch. My knock stayed in the low 20's. Once I get a good twin plate clutch I'll push the limits further, and one of these days I plan to build a water injected compound supercharger/turbo setup. Immediate boost response with the power potential of over 800rwhp.... I'll probably stick closer to 600rwhp to keep costs down. I have too many projects..

 

Yea, 2 blowers have best of both worlds. I figured i would just buy the whole kit. You said it works in trunks with a check valve (makes scene) so ill just buy the whole thing. We get any "discount" b/c rx7club memeber hehe. I just want black hose instead of blue lol