LS3 / LS2 injectors
Thread Starter
Pro
Joined: Oct 2007
Posts: 538
Likes: 1
From: Niles Michigan
LS3 / LS2 injectors
I was hoping someone could tell me what the difference between the pressure of an LS3 injector vs an LS2 injector? I was also considering new heads and cam for my LS2 motor, but not sure how big of a cam I could use with LS3 injectors. Thanks
Burning Brakes
Joined: Jun 2008
Posts: 1,214
Likes: 3
From: CA
The cam is not going to determine how big of an injector you'll need. It all depends on how much power ur planning on making. I've heard of guys with 500rwhp N/A running LS3 injectors but to be sure you need to look at the injector duty cycle. Or just find someone with a setup similar to what you want and see what injectors they're running.
Racer
Joined: Feb 2007
Posts: 313
Likes: 0
85% duty cycle
I have an 2007 LS2 motor and done extensive work and plan on keeping the motor naturally aspirated. I am interested to hear what others have done with injectors. I was tested at 85% duty cycle at 5,800 rpm. I do not know why they did not take it to 6,800 which is my shift point ( auto) and my guess is I am above 85%.
I am planning on pumping compression ½ point to 11.25. I also will be switching from stock LS2 injectors to LS7 or something else. I have a LS3 intake with LS3 heads on the LS2 motor. For this intake manifold I actually need the slightly taller injector so that is the reason for LS7 injectors.
What other injectors should I consider?
I am planning on pumping compression ½ point to 11.25. I also will be switching from stock LS2 injectors to LS7 or something else. I have a LS3 intake with LS3 heads on the LS2 motor. For this intake manifold I actually need the slightly taller injector so that is the reason for LS7 injectors.
What other injectors should I consider?
Safety Car
Joined: Jan 2004
Posts: 4,974
Likes: 14
From: Pinellas Park Fl
St. Jude Donor '08-'09 & '12, '14
I have an 2007 LS2 motor and done extensive work and plan on keeping the motor naturally aspirated. I am interested to hear what others have done with injectors. I was tested at 85% duty cycle at 5,800 rpm. I do not know why they did not take it to 6,800 which is my shift point ( auto) and my guess is I am above 85%.
I am planning on pumping compression ½ point to 11.25. I also will be switching from stock LS2 injectors to LS7 or something else. I have a LS3 intake with LS3 heads on the LS2 motor. For this intake manifold I actually need the slightly taller injector so that is the reason for LS7 injectors.
What other injectors should I consider?
I am planning on pumping compression ½ point to 11.25. I also will be switching from stock LS2 injectors to LS7 or something else. I have a LS3 intake with LS3 heads on the LS2 motor. For this intake manifold I actually need the slightly taller injector so that is the reason for LS7 injectors.
What other injectors should I consider?
Thread Starter
Pro
Joined: Oct 2007
Posts: 538
Likes: 1
From: Niles Michigan
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Former Vendor
Joined: Feb 2012
Posts: 26,512
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From: ST. CHARLES IL
The stock injectors are usually fine unless you get into forced induction or a serious N/A build. We have all sorts of fair priced upgrades if you need something.
Here is some fun math for you guys
WHAT SIZE FOR YOUR CAR?
THE MATH -
1. Take your target peak horsepower and multiply by
- .5 for naturally aspirated
- .6 for supercharged engines
- .625 for turbocharged engines
2. Take that figure and divide it by number of cylinders
3. Divide by .9 (for 90% duty cycle)
This will give you the number you need for lb/hour for each injector
EXAMPLE - 700 Horsepower Supercharged engine (700x0.6=420) (420/8=52.5) (52.5/0.8=58.3) So this application would require a 58.3lb/hour or larger injector. As a general rule you should always go to the next highest size.
Here is some fun math for you guys
WHAT SIZE FOR YOUR CAR?
THE MATH -
1. Take your target peak horsepower and multiply by
- .5 for naturally aspirated
- .6 for supercharged engines
- .625 for turbocharged engines
2. Take that figure and divide it by number of cylinders
3. Divide by .9 (for 90% duty cycle)
This will give you the number you need for lb/hour for each injector
EXAMPLE - 700 Horsepower Supercharged engine (700x0.6=420) (420/8=52.5) (52.5/0.8=58.3) So this application would require a 58.3lb/hour or larger injector. As a general rule you should always go to the next highest size.
