Here's my stats:

350 Superram
AFR190 heads 64cc chambers
CAM 218/224 @.050 .495/.502 lift 114deg LCA/110deg intake center
52mm throttle body
3.27 rear gears
Probuilt 700R4
Vigilante 2800 stall
SLP 1 5/8 heads, 3” cat back, Catco highflo converter
MSD Digital 6
Accessory brackets converted to 88+ serpentine
Walbro 255 high volume in tank pump

I am looking at adding a D1SC for ~8lbs boost with the 749 ECM. I need suggestions on the injector size I will need to run.

Thanks

 

well are you going to run the injectors before you get the blower?

if yes, then are you going to install the 749 also before the blower (same time as injectors)?

if no, then answer = keep current injectors

 

Yes, I will be installing both at the same time injectors & 749 ECM probably just before blower or at the same time I install blower.

 

http://www.smokemup.com/auto_math/index.php has an injector sizing thing.

you have to register to use it tho.

 

I'm guessing you will make about 425-450 at the crank before the boost and maybe 600-650 after you add your 8#. Your fuel requirement is 37 pph for a 600hp motor at .5 bsfc, on the other end of the window with 650 hp at .6 bsfc you woud require 49 pph per cylinder.

So in order to not run the injectors static you would need between a 42 - 55 pph injector. If you pick something in that range you should be able to use fuel pressure to get the injector flowing the right amount

 

So based on my current combo and your guestimate on the horsepower I would be producing it probably is not too smart putting a supercharger on the stock shortblock w/ hypercrap pistons. From what I've read stock crank/rods/hypercrap pistons are only good to about 500 hp.

Is my thinking right? Or is your guestimate very optimistic?

Thanks

 

I don't think I'm being too optimistic... I am assuming you will properly prepare the motor and that it will be tuned well. Go take a look at AFR's web page to see how much power they are making with mild combos like yours.

Adding 8# of boost is usually good for about a 35-40% power increase. Thats based on a 1.54:1 pressure ratio, adiabatic efficiency of centrifical compressors and some power lost to drive the thing.

 

I'm with Dan. Properly tuned that's exactly where you will be hp wise. You'll see a little less at the crank, but that's because the blower will probably be sucking up anywhere from 25-60hp, but you still have to feed it.

Considering that you'll probably be pretty close to the stock compression with the stock long block and 64cc chambers, you'll probably end up running some extra fuel to stay out of detonation, which will put your BSFC closer to .6 or so.

The way these thigns go, I'd be somewhat conservative with my injector choice and try to stick to an 85% duty cycle or less, that will have you looking for a 57lb/hr or larger set of injectors.