Injector Size

My mods this far are:
Big 16G turbo, 3" down pipe, race cat, 3" catback, balance shafts eliminated, solid motor mounts, 255Lph fuel pump, ACT 2100 Clutch. ETS front mount intercooler and piping. ETS intake pipe.
As far as engine goes I have a rebuilt engine with Wiseco Pistons and Eagle Rods.

My plans are to eventually go with a big turbo. I want an injector that can handle a bigger turbo or higher boost at the track. At the same time with the high gas prices these days I'd rather not have an injector that is going to waste TOO much gas while i'm on the smaller turbo. I have an SAFC2 that I'm going to use to tune the new injectors. Any other things I could add to the SAFC to make it better for handling larger injectors? Right now I'm thinking of FIC 950's how does this sound?



I know I'm going to get alot of people suggesting DSMlink. That's in the works for the future too. For now I wanna use the AFC I have.

 

[464/2K]

yes get dsmlink and 1000cc. that way you never have to upgrade again.

 

[belize1334]

With 1000cc injectors your fuel pump is going to run out LONG before the injectors do.

 

[CP]

You need a bigger fuel pump than the 190.

 

[atc250r]

Injectors will have no effect on fuel economy as long as they are being compensated for properly. I get over 25mpg on the highway with my VPC and 720's. Get a set of Denso 720's, have them cleaned and flowed, then have Jeff burn a chip to compensate for them. You can use the SAFC to fine tune it once the KD Chip is in.

John

 

Go with the denso 720's & get a chip from Jeff. This can put you well into the 500+ hp range. You'll need to upgrade the fuel pump very soon so keep that in mind.

 

Quote:
From what I've heard the SAFC is only really able to handle up to 7XX's.



If you remove that much airflow with an AFC you will have so much knock that you will have to run less boost than you are now. /ubbthreads/images/graemlins/wink.gif
The ECU uses the amount of airflow (load) to decide which AFR and timing maps to use. For every 10% you remove on an AFC you are going to have to deal with ~2 degrees more advance, which is counterproductive to running more boost on pumpgas.
We fought this issue for many years, until I figured out how to remove the fuel from the chip instead, and then DSMLink now offers even more tunability, but the results are the same: removing FUEL instead of AIRFLOW is the only right way to do it. /ubbthreads/images/graemlins/wink.gif

 

[WesS]

^^^^--I learn something everytime you post. I love it!

 

[turbowop]

Quote:
I get over 25mpg on the highway with my VPC and 720's.



Hell, even I get that type of mileage with my 950's and Maftpro...until I start stomping the pedal down to pass people. /ubbthreads/images/graemlins/grin.gif

 

[Brianawd]

I have got a best of 21.7mpg with e85 and 1600cc injectors, and with my old set up I got 27 mpg with my 550cc injectors

 

Is the 190 LPH fuel pump really that bad?! From what I was told It'll be able to handle street fuel needs. What is it's limit injector wise? Can anyone correct me if I'm wrong?

 

Anyone?

 

[ggsxkid]

a 255 would be a better candidate for handling "street mods"

 

What about the 190. What is it's range for injectors. I have one in now. I'd rather not change it quite yet. If i have to then so be it. But what can I expect it to handle? Anyone have any knowledge on this subject?

 

[Rausch]

this should help a bit...

 

The way you read that chart is like this:
"12.5 volts" would be about right for a NON-rewired fuelpump
"58" would be equal to you running 21 psi of boost on top of your stock 37 psi fuel pressure
"145.11" equals the liters of fuel per hour that the fuelpump could pump at that 58 psi fuel pressure.
So, is that enough??
Let's say you have 650cc injectors maxxing out at 100% duty cycle (I don't recommend that, but...). That is 4 X .650 liters/minute = 2.6 liters/minute, or 156 liters/hour, almost 10% more flow than the fuelpump can deliver. But, chances are that at 21 psi you are nowhere near to maxxing out 650's, unless you are in Cali running 91 octane. However, the situation gets even worse as you raise the boost. The chart doesn't give enough enough datapoints to calculate this exactly, but at 25 lbs of boost and 62 psi fuel pressure, where the 650's are getting closer to maxxing out, that fuelpump will be well below 125 liters/hr, so you WILL lean out.
I guess it all depends what you consider a "street" car. /ubbthreads/images/graemlins/wink.gif

 

So would rewiring my fuel pump allow the pump to be able to handle 660s? Where do you get the number for the fuel pump PSI?

 

[speedyvr4]

my buddy ran a 190 with a 50 trim and it was way more then enough fuel. But a 50 trimm isn't considered a "big" turbo anymore. You could get the 255 as cheap insurance, at 100 bucks a pop, it's way cheaper then running lean and breaking something internal.

 

Quote:
So would rewiring my fuel pump allow the pump to be able to handle 660s? Where do you get the number for the fuel pump PSI?



As I said, "58" in the "PSI" column represents the fuelpumps pressure, 37 base psi plus 21 boost psi = 58 psi in my example.
If you look right below that in RRE's chart, you will see another set of data for 14 volts, which roughly represents the voltage the pump will see if it is rewired. In that case, the 190lph can deliver "162.78" liters/hour, which is more than 4 650cc injectors can deliver, so it is fairy well matched to 650cc injectors. It all depends how much boost you plan on running. The more boost, the less VOLUME the fuelpump can pump.When that volume drops down below the amount of fuel that the injectors need, you WILL lean out.
4 X 660cc = 2.64 liters/min X 60 = 158.4 liters/hour.
Jeff Lucius has done a ton of fuelpump testing, and although he doesn't show the Walbro 190lph plots, you can plot the few datapoints that RRE gives you, and see how they parallel some of the tested pumps, to get an idea where it will be:
http://www.stealth316.com/2-fuelpumpguide.htm
My best guess is that it will work fine up to ~25 lbs of boost on pumpgas, if rewired.

 

I second the 1000cc dsmlink, i just upgraded from 550ccs and an afc and after about 10 min of tuning it already idles and cruises better than the afc ever did, plus now i can run the boost i want.