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DestinWahoo
01-31-2007, 02:13 PM
Trying determine fuel injectors for my 1994 Cobra Mustang rebuild


347 DSS N/A Stroker, est. 450 hp

Start point: less than 1 lb fuel/ per 1 hp/ per 1 hour

BSFC # for N/A: .4 to .5 lbs/hp/hr
<O:p</O:p
So,
<O:p</O:p
450 hp x .5 = 225 lbs of fuel/hr
<O:p</O:p
225 lbs/hr/8 injectors = 28.1 lb/hr per injector
<O:p</O:p
Use 80% duty cycle for injectors: 28.1/.8 = 35.2lb/hr
<O:p</O:p
So, it looks like injectors around the 36 lb to 39 lb per hr are needed.
<O:p</O:p
Any comments on the injector size?
<O:p</O:p
What brand injectors to use?

venomous
01-31-2007, 11:03 PM
Is 450 flywheel or rear wheel HP? My Car maxed out 42# injectors at 484 rwhp. Better safe than sorry.

blk04cobra1
02-01-2007, 10:16 AM
Just do 42's and a lightning meter...they'll support enough until you wanna go over 550rwhp :thumbsup:

DestinWahoo
02-01-2007, 12:17 PM
Thanks for the input. I had selected FRPP matched 42lb'ers, but needed to know if my thoughts were wrong.

blk04cobra1
02-01-2007, 11:49 PM
Thanks for the input. I had selected FRPP matched 42lb'ers, but needed to know if my thoughts were wrong.
nah, but be sure to get a custom dyno tune after the install...it used to be that the lightning meters were calibrated for the 42's, but here recently they have not come pre-calibrated :thumbsup:

Pro-Dyno
02-11-2007, 03:47 PM
Actually it is all calibrated in the pcm and with a fox body you would have to have it tuned the maf curve for obd2 is completely different than an eec4 (foxbody) you could also use one of the new professional mass air meters.:thumbsup:

DestinWahoo
02-12-2007, 08:48 PM
Dan, Mine is an SN95 and I have no problem with coming up to SC from Florida for a great tune. With the new DSS motor going in in March, the increased HP and with it being a red headed step child ride, 1994 Rio Red Cobra, I need some input on the electronics. PM your thoughts on what it will take to get her hot.

DestinWahoo
02-28-2007, 09:19 AM
I contacted Aeromotive and Anderson Ford Motorsports for Injector size.
I got two very different answers. Aero says 50lb injectors, where as, AFM says 38lb injectors will work fine.
My calculations show the 38lb in range, but I want to get right the first time and not rebuy.
The engine arrives next week and I need to get my tail in gear.

Here is the specs on my engine for reference;

LONGBLOCK: 347 SB2002 PRO BULLET FT/TW:

347 cid short block Balanced to racing tolerances and blueprinted.

RODS: 4340 forged steel ultra-lite 5.400" I-beams w/ ARP bolts & full floating pins

CRANK: nodular iron 3.40" stroke,

PISTONS: forged Pro-X # 4320 (FT/TW -3cc),

RINGS: moly E-458K,

ROD BEARINGS: tri-metal CB-634P,

MAIN BEARINGS: tri-metal BC240J,

CAM BEARINGS: tri-metal CC440

MAIN SUPPORT SYSTEM: 6061-T6 X 3/4" ALUMINUM

CYLINDER HEADS: Trick Flow Twisted Wedge 185CNC ported heads, 2.02/1.60 valves, #51400004-C01

INTAKE: Trick Flow Track Heat (TFS-51511002)

ADAPTER: Trick Flow (TFS-5150SN95-11)

PHENOLIC SPACER: 1” (TFS-51520008)

TIMING CHAIN: Pro Gear 3 Position

430HDSTK LIFTERS: Ford Racing

RETAINING HARDWARE: Hydraulic

PUSHRODS: 4130 .080" Wall Seamless

HEAD BOLTS: ARP 8740 Hex Head Bolts

HEAD GASKETS: Fel Pro Graphite 8548 PT2

ROCKER ARMS: DSS Aluminum Roller Rockers

T-WASHERS: 1/2" to 7/16" reducer bushings for cylinder heads

CAMSHAFT: Comp Cams XE274HR Roller (.555"/.565" 224°/232°@.050"

112°LSA 2200-6200RPM) (35-518-8)<O:p></O:p>

BALANCER: 28oz SFI Steel/Aluminum balancer 1 (208SA)

FLYWHEEL: Fidanza SBF 157T/late model SFI aluminum flywheel

(28oz balance,replaceable friction surface) (186501)

WINDAGE TRAY: 5.0 Stroker Pro Tray 1 (7005)

ARP flywheel bolts: 7/16" x 1.00" 6pcs (manual trans) (100-2801)

ARP balancer bolts: 289-460 except 351C (150-2501)

OIL PAN: OP7050 DSS low profile 7qt oil pan with pickup and
passenger side 3/8" NPT baffled oil return hole (for supercharger/turbo).

OIL PUMP: OP1000 DSS 302 std volume oil pump kit Includes pump
w/ adjustable pressure, heavy duty oil pump and pickup
fasteners, and an ARP heavy duty oil pump driveshaft.

DISTRIBUTOR: MSD #8455

THROTTLE BODY: PP 75mm (69212)

Pro-Dyno
02-28-2007, 09:35 AM
I would go with the 42's with a 12.5 afr they should go 500rwhp pretty comfortably. If you feel it will make more then bump to the 50's but you will need a different meter the lightning meter will only support 450-480rwhp professional mass air makes a nice piece hope it helps.:thumbsup:

I contacted Aeromotive and Anderson Ford Motorsports for Injector size.
I got two very different answers. Aero says 50lb injectors, where as, AFM says 38lb injectors will work fine.
My calculations show the 38lb in range, but I want to get right the first time and not rebuy.
The engine arrives next week and I need to get my tail in gear.

Here is the specs on my engine for reference;

LONGBLOCK: 347 SB2002 PRO BULLET FT/TW:

347 cid short block Balanced to racing tolerances and blueprinted.

RODS: 4340 forged steel ultra-lite 5.400" I-beams w/ ARP bolts & full floating pins

CRANK: nodular iron 3.40" stroke,

PISTONS: forged Pro-X # 4320 (FT/TW -3cc),

RINGS: moly E-458K,

ROD BEARINGS: tri-metal CB-634P,

MAIN BEARINGS: tri-metal BC240J,

CAM BEARINGS: tri-metal CC440

MAIN SUPPORT SYSTEM: 6061-T6 X 3/4" ALUMINUM

CYLINDER HEADS: Trick Flow Twisted Wedge 185CNC ported heads, 2.02/1.60 valves, #51400004-C01

INTAKE: Trick Flow Track Heat (TFS-51511002)

ADAPTER: Trick Flow (TFS-5150SN95-11)

PHENOLIC SPACER: 1” (TFS-51520008)

TIMING CHAIN: Pro Gear 3 Position

430HDSTK LIFTERS: Ford Racing

RETAINING HARDWARE: Hydraulic

PUSHRODS: 4130 .080" Wall Seamless

HEAD BOLTS: ARP 8740 Hex Head Bolts

HEAD GASKETS: Fel Pro Graphite 8548 PT2

ROCKER ARMS: DSS Aluminum Roller Rockers

T-WASHERS: 1/2" to 7/16" reducer bushings for cylinder heads

CAMSHAFT: Comp Cams XE274HR Roller (.555"/.565" 224°/232°@.050"

112°LSA 2200-6200RPM) (35-518-8)<O:p></O:p>

BALANCER: 28oz SFI Steel/Aluminum balancer 1 (208SA)

FLYWHEEL: Fidanza SBF 157T/late model SFI aluminum flywheel

(28oz balance,replaceable friction surface) (186501)

WINDAGE TRAY: 5.0 Stroker Pro Tray 1 (7005)

ARP flywheel bolts: 7/16" x 1.00" 6pcs (manual trans) (100-2801)

ARP balancer bolts: 289-460 except 351C (150-2501)

OIL PAN: OP7050 DSS low profile 7qt oil pan with pickup and
passenger side 3/8" NPT baffled oil return hole (for supercharger/turbo).

OIL PUMP: OP1000 DSS 302 std volume oil pump kit Includes pump
w/ adjustable pressure, heavy duty oil pump and pickup
fasteners, and an ARP heavy duty oil pump driveshaft.

DISTRIBUTOR: MSD #8455

THROTTLE BODY: PP 75mm (69212)

blk04cobra1
02-28-2007, 10:39 AM
I would go with the 42's with a 12.5 afr they should go 500rwhp pretty comfortably. If you feel it will make more then bump to the 50's but you will need a different meter the lightning meter will only support 450-480rwhp professional mass air makes a nice piece hope it helps.:thumbsup:
not trying to be an ass, but didnt I say that above? Thank you, drive through please :thumbsup: :bounce: (I like the bouncy guy)