Fuel injectors opening time??
Thread Starter
Instructor
Joined: Nov 2000
Posts: 185
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From: Finland
Fuel injectors opening time??
Hello everyone
I have now a custom chip with a fuel injectors opening time set to 1,7ms with a 30lbs/hrs injectors. But this winter im gonna go for more power and bigger injectors, maybe 40-50lbs/hrs. What opening time do you have with that large injectors??
thanks
Tomas
I have now a custom chip with a fuel injectors opening time set to 1,7ms with a 30lbs/hrs injectors. But this winter im gonna go for more power and bigger injectors, maybe 40-50lbs/hrs. What opening time do you have with that large injectors??
thanks
Tomas
Melting Slicks
Joined: Apr 2001
Posts: 2,105
Likes: 220
From: Ca.
Re: Fuel injectors opening time?? (Tomas)
It's not opening time, but duty cycle that determines what size inj. you need....
The commonly accepted formula is inj. pulse width X rpm divided by 600=inj. duty cycle (for batch fire)
For sequential inj. pulse width X rpm divided by 1200= inj duty cycle.
And you don't want to go much over 80% duty cycle.
Don't go too big-it then gets difficult to tune for idle areas.
The commonly accepted formula is inj. pulse width X rpm divided by 600=inj. duty cycle (for batch fire)
For sequential inj. pulse width X rpm divided by 1200= inj duty cycle.
And you don't want to go much over 80% duty cycle.
Don't go too big-it then gets difficult to tune for idle areas.
Thread Starter
Instructor
Joined: Nov 2000
Posts: 185
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From: Finland
Re: Fuel injectors opening time?? (drive it)
Hello Drive it
Thanks for the reply. What size of injectors do you think i should go for? I have drive 11,72 with my car so approx 450-500Hp i should have?? This winter i will try to get more power, but i dont know how big injectors i should go for?
Thanks for the reply. What size of injectors do you think i should go for? I have drive 11,72 with my car so approx 450-500Hp i should have?? This winter i will try to get more power, but i dont know how big injectors i should go for?
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Re: Fuel injectors opening time?? (Tomas)
Tomas, in normally aspirated trim 30lb units are still adequate. To calculate injector size use this formula:
(Horsepower x BSFC) / (Number of inj x Duty cycle)
BSFC = .50 for normally aspirated engs, .60 to .65 for blown, and turbo
Duty cycle = .80 (80%) in normal applications for sizing
Where are you in Finland? I have been to Helsinki and I spend 6 weeks in Tampere a few years ago.
[Modified by tjwong, 8:55 AM 9/30/2003]
(Horsepower x BSFC) / (Number of inj x Duty cycle)
BSFC = .50 for normally aspirated engs, .60 to .65 for blown, and turbo
Duty cycle = .80 (80%) in normal applications for sizing
Where are you in Finland? I have been to Helsinki and I spend 6 weeks in Tampere a few years ago.
[Modified by tjwong, 8:55 AM 9/30/2003]
Thread Starter
Instructor
Joined: Nov 2000
Posts: 185
Likes: 0
From: Finland
Re: Fuel injectors opening time?? (tjwong)
Hello tjwong
thanks for the reply. If I calculate with this formula with approx. 500Hp I must have 50lbs/hrs injectors, I have drive with 30lbs since -99 my with my setup.
I live here in Finland http://www.aland.fi/virtual/eng/frame.html
thanks for the reply. If I calculate with this formula with approx. 500Hp I must have 50lbs/hrs injectors, I have drive with 30lbs since -99 my with my setup.
I live here in Finland http://www.aland.fi/virtual/eng/frame.html
