Auxillary Injection (Water/Meth) 50/50 mix
 

Alright, I installed a efr 8374 turbo and I am going to tune with a D07 nozzle delivering approximately 566CC of 50/50 water/meth mix on a stage 2 devils own kit. I know this is good for around 400WHP and that is about where the car will be run at.


The question is this. We run water/meth to protect the engine against detonation. I am running the powerFC and BW stock boost controller. The powerfc works like this. You input a boost settings, guess the duty cycle and it should control the boost. if boost runs away from the boost setting of greater than .25 KG/CM2 the powerFC will cut fuel.


So on a run away boost issue the powerfc will cut fuel........if you are injecting water/meth.....you get my point right?

Also, couldn't this same thing happen when you hit the rev/limit fuel cut but you are still injecting water/meth........anyone actually hit a rev limit while injecting? or hit the fuel cut because of the boost cut?

I have no idea about the powerfc but im bouncing off the rev limiter all the time - i should probably use more constraint, or get a big arse shift light, lol - 400hp efr8374, 300cc 80/20 water /meth, Aem controller. No adverse effects as far as i can tell.

The Aem is boost controlled though, boost cut = WM inj cut. Not sure how water injected into and engine on overrun will affect anything - interesting question and i look forward to hearing others' insight.

Devilsown lists the DO7 as 7 GPH which is 441 CC/Min. this is in accord w nozzle ratings as an M1 is 63 CC/Min so an M7/DO7 is 7 X 63 or 441.

let's say you are making 375 hp when you get runaway boost

375 rotary rwhp requires 2706 CC per minute at 11 AFR.


83,004 BTUs to make 375

you are injecting 220 CC of water and 220 CC of meth.

Negative/cooling BTUs in 220 CC of water are 469

BTUs in 220 CC of meth are 3320

3320 - 469 = 2851 BTUs

if you have fuel cut and the AI continues to run you will be injecting 3.4%
fuel into the motor compared to what you were using at 375 or enough to make 12 hp.

i doubt it will be an issue for you.

BTW, good for you for running the system.

Howard

Thanks for the response. I got real world data from devils own to ensure just how much I am injecting. The pumps are pre-set to 200PSI from the factory, voltage is tested at 12V, I have about 13.8-14V from my car, which is roughly 220PSI, the flow varies by nozzle size and real world testing puts the pressure at 170PSI with 12V for a M7, figure about 190PSI with my voltage.

190PSI - 20PSI = 170PSI roughly, 1.303 * 441 = 574CC/Min of flow. that will be roughly the max flow for the pressure. Right where it needs to be.

Will tune the car as soon as we get nice weather and some free time.

I ran 18psi through a GT4088R with 9.7:1 CR and 550cc of 70/30 W/M for the better part of a year. I had no issues and the engine ran great.