Sti+20G+Stock injectors+WI?

[TheMadScientist]

Any thoughts?
I all most installed my DB20G lastnight. I think with the WI this should be OK to run. I might max out the injectors but with the WI I should be able to run much leaner so the IDC should come way down.

Has anyone done a 20G on stock injectors and WI?

TMS

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[ride5000]

doooo eeeeeet.

it'll be fine.

if it's not, get yourself an AFPR. works for me!

[olsaltybastard]

I agree that the WI will let you run leaner, but probably not lean enough where the stock injectors are going to be able to compensate for the amount of air a DB 20G is gonna push. WI removes the fuel required to cool the cylinders, not the fuel required to maintain proper burn. Of course, when I hear WI, I'm thinking that you are going to use water, rather than methanol or some other type of fuel.

If I'm wrong, nothing happens. If I'm right, you're engine is gonna be short lived.

[TheMadScientist]

I am running a 50/50 mix of eathanol/water. I have enough gauges and loggers to keep an eye on things. I think I am going to try it. If I run out of fuel on the stock injectors I can all ways turn down the boost and wait until I get the AFPR installed.

TMS

[ride5000]

YES!

[Nixlimited]

I definitely want to hear the results.

[hippy]

I think you're gonna want bigger injectors. I'm running an 18g on a wrx with jdm sti injectors and water injection, and I come close to maxin em out at 12.5 to 1.

peace

[TheMadScientist]

Originally Posted by ride5000

YES!

Bastard

It is in. For anyone installing a 20G GET AN INLET HOSE. I know alot of people will say it is not needed but I am sure it would make the install easier.
I have a piece of hose as my boost control right now as I didn't have the right fittings to hook up the GM BCS. Now I need to go drive it.

TMS

[TheMadScientist]

18.5psi
<11:1 AFR
5500rpm
1500F EGT
10gph 50/50 water/eathanol
75%idc

No logs yet. I was using my SM3 for IDC, boost and AFR. The audible rev light for RPM and my Autometer EGT gauge.


TMS

[mpower22]

It is probably possible but really a short term solution. I will have my tune finished tomorrow by Jorge

New Slowboy 20g
smc kit 50/50 denatured/water comming online at 8 psi
perrin fmic
perrin inlet
perrin big maf
ur 780 cc injectors/rails
turboback exhaust

looking for high 300's on a dynapack

we'll see tomorrow

Matt

[ride5000]

Originally Posted by TheMadScientist

18.5psi
<11:1 AFR
5500rpm
1500F EGT
10gph 50/50 water/eathanol
75%idc

No logs yet. I was using my SM3 for IDC, boost and AFR. The audible rev light for RPM and my Autometer EGT gauge.


TMS

nice logger...

looks like you've still got fuel. i'd like to see the idcs @ 6k5, and maybe another psi of boost..

and <11:1?? c'mon man. i'm pushing close to 12s nowadays!!!

[NavyBlueSubaru]

Um I think that the 10gph is excessive. Other than that, good setup. According to aquamists calculations and other various W.I. tuning sources, you ultimately want to run between 10% and 20% water/alky in relation to your fuel, or a water:fuel ratio of 1:10 and as much as 2:10. You would be better off with a 1gph nozzle or maybe a 2gph if you are flowing lots of air. I am running a 1gph at 7psi and another 1gph nozzle kicks in at 14psi.

Now since you are running 50/50, half of your injection can be treated like fuel. That is like having a 5th fuel injector, in a matter of speaking. With that being the case you can probably run a higher ratio of spray:fuel but still a 10gph is really too much. Check out the aquamist thread in the engine management section and see what you can find, there is a lot of good info in there.

Jeff

[hippy]

I agree, but 2gph isn't a lot of water(126cc/min). Running 20% water to fuel isn't so normal unless you're running leaner then 11 to 1. At 11 to 1 a/f ratio, even a 10% water to fuel ratio would be a 10 to 1 air to liquid ratio. 20% water to fuel at 11 to 1 a/f would be like running a 9.2 to 1 air to liquid ratio(imagine running more then 20% water to fuel at 11 to 1.....). At 20% water to fuel, you'd need to run 12 to 1 or leaner to keep the air/liquid ratio above 10 to 1. When running 315cc/min of water(like you are), you'd need to be putting out 1575cc/min(or more if you're counting the alc) of fuel to stay below a 20% water to fuel ratio. So it would probably be good to at least lean out the a/f ratio to 12.5 to 1 to try and keep the air/liquid ratio leaner(20% water to fuel at 12.5 to 1 a/f is still 10.4 to 1 air/liquid which is pretty rich in most peoples books).

At 12.5 to 1 a/f ratio ya won't need as much water to get a 20% water to fuel ratio. You'd probably have to run higher then 70% idc's to stay below a 20% water to fuel with a 10gph nozzle, and the idc's wouldn't be as high as they are now with the leaner a/f ratio(so you'd probably be running more then 20% water to fuel all the time). Having two 5gph(or two 4gph) nozzles might be better, one turning on at a given rpm(like 5500...) when the idc's get above 60 or 70%. Just some food for thought I guess.

peace

[TheMadScientist]

I am running a progresive controller. The turn on point is 7psi and I have the max set to 22psi. I never get to full flow because I am only running 18psi. SMC supplies 10gph nozzles with all thier Sti kits, and 7gph for the WRX kits. I haven't even started tunong AF or timing yet. I am trying to get the boost stable with Street Tuner and the GM solenoid first. Then I will tune the Utec WI map, but I think I should install a GM 3bar MAP first.

TMS

[hippy]

Do you have the new utec firmware or something? What do you mean by utec water injection map?

[TheMadScientist]

A map tuned for WI.

TMS

[TheMadScientist]

Here is a log 4th gear no water 17psi peak.

 4th Gear
 4140  +2.7 3.7 101  10	00   +24.0   45.8 ECU.   +0.0 ECU.   3.7
 4084  +1.7 3.8 102  40	00   +24.1   55.1 ECU.   +0.0 ECU.   3.9
 4246  +4.3 4.0 102  50	00   +23.4   62.6 ECU.   +0.0 ECU.   4.0
 4208 +10.2 4.1 102  50	00   +22.3   65.1 ECU.   +0.0 ECU.   4.1
 4345 +12.9 4.0 102  70	00   +20.1   68.5 ECU.   +0.0 ECU.   4.0
 4329 +13.9 4.1 102  70	00   +19.8   69.4 ECU.   +0.0 ECU.   4.1
 4420 +15.3 4.1 102  70	00   +19.8   68.1 ECU.   +0.0 ECU.   4.1
 4409 +16.3 4.1 102  80	00   +20.2   66.8 ECU.   +0.0 ECU.   4.1
 4492 +15.9 4.1 102  70	00   +20.7   69.7 ECU.   +0.0 ECU.   4.1
 4553 +16.3 4.1 102  70	00   +18.4   72.4 ECU.   +0.0 ECU.   4.1
 4559 +16.1 4.2 102  70	00   +18.8   72.3 ECU.   +0.0 ECU.   4.2
 4629 +15.9 4.1 102  70	00   +18.9   70.8 ECU.   +0.0 ECU.   4.2
 4675 +16.5 4.1 102  70	00   +19.0   73.4 ECU.   +0.0 ECU.   4.2
 4701 +15.9 4.1 102  70	00   +19.5   71.4 ECU.   +0.0 ECU.   4.2
 4816 +15.9 4.2 102  70	00   +19.8   72.3 ECU.   +0.0 ECU.   4.2
 4761 +16.1 4.2 102  70	00   +19.8   76.9 ECU.   +0.0 ECU.   4.2
 4823 +15.9 4.2 102  70	00   +19.7   78.3 ECU.   +0.0 ECU.   4.3
 4803 +16.1 4.2 102  70	00   +19.7   74.7 ECU.   +0.0 ECU.   4.3
 4967 +16.3 4.3 102  70	00   +19.8   80.7 ECU.   +0.0 ECU.   4.3
 4960 +16.3 4.2 102  80	00   +20.9   77.2 ECU.   +0.0 ECU.   4.3
 5175 +16.1 4.3 102  70	00   +21.1   75.5 ECU.   +0.0 ECU.   4.2
 4990 +15.9 4.3 102  70	00   +21.1   79.4 ECU.   +0.0 ECU.   4.3
 5089 +16.1 4.3 102  80	00   +20.8   78.6 ECU.   +0.0 ECU.   4.3
 5073 +16.3 4.3 102  80	00   +21.0   78.6 ECU.   +0.0 ECU.   4.3
 5208 +16.8 4.3 102  70	00   +21.0   80.1 ECU.   +0.0 ECU.   4.3
 5282 +17.2 4.3 101  70	00   +20.8   84.2 ECU.   +0.0 ECU.   4.3
 5200 +17.2 4.3 102  80	00   +20.6   83.2 ECU.   +0.0 ECU.   4.4
 5274 +17.0 4.3 101  80	00   +20.7   80.7 ECU.   +0.0 ECU.   4.4
 5393 +17.2 4.3 101  80	00   +20.5   86.2 ECU.   +0.0 ECU.   4.4
 5402 +17.2 4.4 101  80	00   +21.4   84.9 ECU.   +0.0 ECU.   4.4
 5376 +17.2 4.4 101  80	00   +21.2   86.4 ECU.   +0.0 ECU.   4.4
 5464 +17.2 4.4 101  80	00   +21.1   90.0 ECU.   +0.0 ECU.   4.4
 5527 +17.6 4.4 101  80	00   +21.2   86.4 ECU.   +0.0 ECU.   4.4
 5602 +16.8 4.4 100  70	00   +21.2   84.4 ECU.   +0.0 ECU.   4.4

Sorry for the low RPM peak. I am so used to shifting ~5500 with the stock vf39, it is hard to change that habit.

TMS

[TheMadScientist]

Forgot to add :
Stock exhaust
Stock intake

TMS

[Davenow]

Originally Posted by NavyBlueSubaru

Um I think that the 10gph is excessive.
Jeff

That would be because you have a WRX, they work great with a 7gph.
10gph is the standard nozzle size on STI's. 7-8gph is standard on a WRX. 5GPH isnt enough on an STI and we have already been through that on Marks car.

[wrex03]

know issue running stock timing? Interesting!

[TheMadScientist]

That is Street Tuner stage 1 timing. I made a couple of tweaks to the dynamic advance but nothing drastic.

TMS

[NavyBlueSubaru]

Well having a 10gph nozzle is much more understandable when you have it running at varied duty cycles. I was under the impression that it was an on/off system. All the calculations i've made in excel show that a 3-5gph nozzle would be the absolute most anybody would want, even if you are making some serious power. You are running at less than full flow but even at only 50% it still seems like way too much.

FWIW, Aquamist supplies nozzles that range from 120 - 310 cc/min, which equals 1.9 - 4.9 gph. They also utilize varying duty cycle setups so it varies the flow as needed.

Anyways its obviously working great for you and thats cool. Cant wait to see the setup when you get it dialed in and the afr's where they need to be.

Jeff

[TheMadScientist]

I finally ran some flow #'s.
At 100% duty flow through the 10gph nozzle is 630cc/min. 50/50 mix would be 315cc/min of water the rest would be fuel. I am running a peak of 18psi with over boost cut set at 19psi. The controller starts at 15% duty cycle at 7psi it would reach 100% duty cycle at 22psi and the ramp is linear. So that means at 18psi the pump should be running ~77.3% duty cycle. So my full flow at 18psi is 486.9 cc/min so 243 cc/min of water. That acually seems a little low to me, at 100% injector flow that would be ~13% water to fuel flow. If you include the alcohol that goes even lowwer.
The log I posted shows 86.4% IDC so that would work out to a 14.7% water to fuel again not including the alcohol.

Anyone know if I should be including the alcohol as water or fuel in my calcs?

TMS

My #'s may be way off as I just did this quick.

[hippy]

It counts as fuel, but different from gas since ya need to put more in to get the same lamda. Ie- The alc is fuel cause it can be burned and makes the a/f reading on a wbo2 richer, but when you're wbo2 reading says 11 to 1(and you're injecting the alc) your engine will be running richer. This will also make the air/liquid ratio richer.......

Your example of the log is misleading since you run lower idc's when you're injecting the alc(cause it makes the a/f ratio richer), and just cause you're running a given idc, that doesn't mean you're actually puting out that percent of your fuel systems capacity(at least I don't think so). Ie-84%idc might be 60% of the fuel that would be injected at 100% idc, or 84% idc might be 90%. Who really knows?

We do know that you're most likely running 11% or more water to fuel(if you're counting the alc as fuel). This means that at 12.5 to 1 a/f ratio, the air/liquid ratio will be 11.26 to 1 when your injectors actually max out their idc's. This isn't so bad as long as you'r running an a/f ratio of 12.5 to 1 and comin close to maxin out your idc's, but if you were to run 12 to 1 the leanest your a/l ratio would be is 10.8 to 1, and with an a/f ratio of 11.5 to 1(which might be what you're running now with the injection) the leanest your a/l ratio would be is 10.4 to 1. All other times the a/l ratio would be richer.

peace

[TheMadScientist]

That log is without WI.

TMS