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When do you need to upgrade injectors and fuel lines??

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Mad Hatter

Gotta go Faster
5,237
4,227
Santiago, Chile
I was hoping to get my motor up to 500 Flywheel hp later this year. Am I ok with the stock fuel system? Or should I be looking at upping injectors and fuel rails?? I had assumed that you only need more fuel for SC setups but saw a few tables that seemed to indicate that I would be right on the edge.
 
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544
You are fine with the stock fuel system at those power levels. For 500 HP at the flywheel, you are only talking about a Cobra Jet intake, throttle body, CAI, long tube headers, and no catalytic converters.
 
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1,119
1,110
Exp. Type
HPDE
Exp. Level
5-10 Years
Lenoir City TN
Time to resurrect an old thread. I hate to start a new one when the topic has already been started. My car made 447 hp at the wheels when it was tuned last year on the stock injectors. The engine has 95k miles on it and it is acting like one of the injectors is starting to clog up. Would you replace with stock size injectors or move up to a larger size? I know the stock injectors will support the current output, but can't help to think that I am nearing their capacity. If you would go bigger than how much?
 
can't help to think that I am nearing their capacity
What did your tuner say the current injector duty cycle is? Most are commonly measured at a max 85% duty cycle, so if you're anywhere around 80-90% you'd want to upsize. If they're still within an acceptable duty cycle, just have them cleaned.
 
What did your tuner say the current injector duty cycle is? Most are commonly measured at a max 85% duty cycle, so if you're anywhere around 80-90% you'd want to upsize. If they're still within an acceptable duty cycle, just have them cleaned.

This. Also because the larger an injector the worse the spray pattern and atomization is, in general, especially at lower duty cycles. So you really only want injectors marginally larger than your power level requires.
 
1,119
1,110
Exp. Type
HPDE
Exp. Level
5-10 Years
Lenoir City TN
I was planning to talk to my tuner the first of the week and see what he says. I was just starting to gather opinions before I talk to him so I know what to ask. Thank you both for you insight.
 

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