Dyno Guesses & Bench Racing Forum - power at wheels

running ls3 6.8 ltr stroker running f1r procharger with a th400 tranny and 3.9 gear set ass end with tru trac center taking guess on pwers

heads? intake? cam? which rearend? what fuel? meth injection?

to many variables.

heads :CNC LS3/L92 Cylinder Heads
intake:fast 102 intake and dbw throttle
cam : 3-Bolt Core Custom Hydraulic Roller Cam
rear end: detroit lsd diff center with 3.9 gear set
fuel:e85



here is full list of engine specs
Type: LS3 6.8L
>> >> >> >> >> >> Displacement: 416 Cubic Inches
>> >> >> >> >> >> Compression Ratio: 9.5:1
>> >> >> >> >> >> Bore x Stroke: 4.070 x 4.000
>> >> >> >> >> >> Rev Limit: 7000 RPM
>> >> >> >> >> >> Crank: Callies Forged
>> >> >> >> >> >> Rods: Callies H-Beam
>> >> >> >> >> >> Pistons: Mahle Motorsports
>> >> >> >> >> >> Cam: Custom 3-Bolt Core Cam
>> >> >> >> >> >> Heads: CNC LS3/L92 Heads
>> >> >> >> >> >> Valve Springs: Nitrided Beehive
>> >> >> >> >> >>
>> >> >> >> >> >> LS3 GMPP Aluminum Block
>> >> >> >> >> >> Plateau Honed to 4.070”
>> >> >> >> >> >> True Surfaced Deck
>> >> >> >> >> >> Engine Block Debured
>> >> >> >> >> >> Blueprinted Shortblock
>> >> >> >> >> >> ACL Rod and Crank Bearings
>> >> >> >> >> >> Callies 4.000” Stroked Crankshaft
>> >> >> >> >> >> Callies Forged H-Beam Connecting Rods
>> >> >> >> >> >> Custom Mahle Motorsports Pistons
>> >> >> >> >> >> CNC LS3/L92 Cylinder Heads
>> >> >> >> >> >> Stainless Intake Valves
>> >> >> >> >> >> Inconel Exhaust Valves
>> >> >> >> >> >> ARP Head Bolts
>> >> >> >> >> >> ARP Main Studs
>> >> >> >> >> >> Cometic Headgaskets
>> >> >> >> >> >> 3-Bolt Core Custom Hydraulic Roller Cam
>> >> >> >> >> >> LS3 Hydraulic Roller Lifters
>> >> >> >> >> >> Black Label Chrome Molly Pushrods
>> >> >> >> >> >> Nitrided Beehive Valve Springs
>> >> >> >> >> >> M-90 Calibrated ECM
>> >> >> >> >> >> fast 102 intake and dbw throttle
>> >> >> >> >> >> aeroflow fuel rails
>> >> >> >> >> >> Custom LS7 Style 62lb/hr Fuel Injectors

If your injectors are rated at 62lb at 43.5psi then they are going to be a limiting factor. They tap out around 850. Not sure how high of fuel pressure you will run. Meth can help this and you are running E85. you will need bigger injectors

Motor has potential for 900-1000 from the parts list.

Ill let someone else step in with a good injector size since I do not use E85 as it is not available locally.

i have a fuel system in the car to im running duel walbro 400 lph intank pumps with a 3 ltr surge and duel bosch 044 fuel pumps and running duel half inch fuel lines to the rails what is suggestion on injector size ?

thanks for your help mate today i found this method to working out injector size

for those who dont know injectors lol
1. Take your target peak horsepower and multiply by
• .5 for naturally aspirated • .6 for supercharged
• .625 for turbocharged
2. Take that figure and divide by the number of cylinders.
3. Divide by .9 (for 90% duty cycle).
This will give you the lbs/hr you will need from each injector.

Example: 520 horsepower, naturally aspirated V8
(520 x .5=260), (260/8=32.5), (32.5/.9=36)
This application would require 36 pound per hour Precision-Flow™
Fuel Injectors (Part #303608). If the formula gives you a number that is not one of
the injector sizes, the general rule is to move up to the next largest size.

Only problem with that formula is that it is for gasoline not E85.

E85 consumes 40% more fuel IIRC but I could be wrong. So whatever size you get with that formula you would need to get 40% bigger flowing injectors.

Plus do not forget that HP rating is at the crank not the wheel. That formula is where I got the information I previously posted.

The way to do this is to do some simple math. You are going to use the multiplying factor of 1.47 to get your size. The 1.47 number represents the difference between the stoiciometric fuel ratio of gasoline and E85. Gasoline is 14.7 and E85 is 10.0