250cc injectors

[Jezza-7]

Im working out some stuff for aquamist and was wondering do the G60 injectors run as 85% duty cycle?

If the car has been remapped would this duty cycle change?

[Yoof]

85% of 250cc....

Your second question doesn't make any sense, change compared to what?

[Jezza-7]

If the engine has been modded a lot, would the duty cycle change?

[Andy]

What you trying to suss out mate?

[Jezza-7]

Water injector to use for the aqaumist.

[Andy]

Looking at your map, your 250cc injectors are running around 75-78% duty cycle on 1 bar boost above 2500rpm or so.

What are the calcs that you're using?

[Jezza-7]

Ok thats good to know,

I have been using this from someones basic working out on their injectors:

4x 750cc injectors = 3000cc/min max flow

lets say i have a max of 80% duty cycle on the injectors
80% of 3000 = 2400cc/min

15% of 2400 = 360cc/min

So mine, if 85% was factory setting, is this:

4 x 250cc injectors = 1000cc

1000 x .85 = 850cc

15% of 850 = 127.5cc

Richard From ERL has said that 0.5 flows around 200cc/min and with 25% methanol im not far from ideal. Awaiting to hear back from him now if its better to go with 0.4 or 0.3.

[Jezza-7]

Aldo can use this one that someone worked out on an rx 7

Injector setup is 2x720cc primaries and 2x1600cc secondaries.

To run 15% water to fuel at 70% IDC, I calculate this way:

(IDC) x (Total fuel cc's) x (Target % water) =
(.70) x (1440 +3200) x (0.15) = 448 cc's of water

Then, also assuming the water nozzles operate at 70% DC and one 0.9 mm WI nozzle flows 315cc (max), I get:

(15% water to fuel) / [(WI flow rate) x (IDC)] =
(448) / [(315) x (.70)] = 2

So I would need two 0.9 mm nozzles to meet my 15%.

Alternatively,
The water (mixture)-to-fuel percentage is roughly 10% with one .8mm nozzle and one .5 mm nozzle in my setup.
Here is how to find that:
To run 10% water to fuel at 70% IDC (assuming), calculate this way:

(IDC) x (Total fuel injector cc's) x (Target % water) =
(.70) x (1440 +3200) x (0.10) = 325cc's of water

Then, knowing the water nozzles operate at 70% DC (from our assumption of IDC) and one 0.8 mm WI nozzle flows 280cc (max) and one 0.5 mm WI nozzleflows 180cc (max), I get:

(required cc's of water) / [(WI flow rate x IDC)] = 10%
(325) / [(280 x .70) + (180 x .70) ] = 10%