Black01M6SS

iTrader: (3)

I know, from my search, that this has been covered a few times but I'm still unsure what I should do for my application. What I'm thinking is that boost referencing would mess up the injector flow rate tables in the tune when under vacuum. I haven't looked at the tables recently but my guess is the flow rate table only goes up to atmospheric pressure so it makes since to me that there needs to be a way to raise the fuel pressure once you exceed atmospheric pressure. The problem I'm seeing is that the regulator would also decrease the fuel pressure when under vacuum which would throw off the injector flow rate table since it already compensates for vacuum.

If this is correct the options seem to be to either flatten the injector flow rate table OR reference the fuel pressure regulator in front of the throttle body so that it only see's atmospheric pressure and boost.

Lets say we went with option number one. If you were going to flatten the injector flow rate table how would you come up with the number to set the table to? I really don't know of a simple way to come up with a number so should I just connect my reference point in front of the throttle body and leave the injector flow rate table alone?

My fuel system is the "Nasty Stage 3 Street Kit" which consist of:

2 Walbro 340 in tank pumps
-8 braided stainless feed fuel line
-6 braided stainless return fuel line
MagnaFuel billet fuel pressure regulator w/boost ref
NastyPerformance Billet fuel rails

I also have RC 75# injectors. Think these will be big enough?

Shooting for 850rwhp out of my 402 with an F1A Procharger. My guess is that boost will be somewhere between 14-18 psi with the pulley combo I have.

One last question: Where are you guys mounting your regulators? I'm about to search but figured I would throw that one in there.

trans2000am

iTrader: (49)

i have the same fuel system im mounting the regulator on the driver side near the abs block. those injectors will support those numbers

Black01M6SS

iTrader: (3)

My line lock solenoid and proportioning valve are where the abs block used to be

BigRich954RR

iTrader: (1)

what pulleys you running?

Blackbird

you base it off your base fp
so take your fp reading with the vacum line off, come up with your flow rate number
put that in all the cells
connect the vacum line
enjoy

sevanseriesta

iTrader: (34)

have you looked at the Injector sticky in the fuel section..... I think 60lb injectors would cover that much power if I remember correctly I think, 75's will support 1000 easy and that is at 80% duty (which is what is said to be maxed)

Black01M6SS

iTrader: (3)

Honestly I've forgotten what pulley combo I ordered. I do remember that it would be around 10k under the max RPM of the blower at 6800rpm though. I can't believe I've forgotten the pulley size. I'll try to remember to look tomorrow when I'm working on it.

I get what you are saying. Turn the pumps on, write down the fuel rail pressure and use that number to calculate the flow rate of the injectors. Enter said value into all cells in the tune file and let the pressure regulator do the work from there. I know I can probably find it somewhere but do you know how I would go about calculating the injector flow rate?

The way I figure it 1000 flywheel HP on a turbo car needs much less fuel than 1000 rear wheel HP on a supercharged car. Just saying they will support 1000HP doesn't really give enough info.

I don't want to start an argument about drive train loss but lets say my goal is 850rwhp. I have a standard trans with a 9" rear so lets say my drive train loss is 15%. I have read that it takes around 150hp to turn an F1A Procharger at this level. So 1150 Engine HP minus 150hp to turn the supercharger equals 1000 Flywheel HP minus 15% drive train loss equals 850rwhp. I know that isn't exact but I think it is safe to say that I will need enough fuel to support 1000hp maybe a little more.