What happens when you reflash your ECU for larger injectors, then go back to stock...
01-08-2007, 09:08 PM
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Engine goes very lean.
Injectors are driven over a duration of time. With the larger injectors the pw was scaled back. Hence the stock injectors will be open for a shorter duration, equaling less fuel.
So don't do it basically.
Injectors are driven over a duration of time. With the larger injectors the pw was scaled back. Hence the stock injectors will be open for a shorter duration, equaling less fuel.
So don't do it basically.
01-10-2007, 03:26 AM
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I have the opposite question, I am running very lean.
14 AFR at WOT. If I switch to bigger injectors 440cc
from 300cc Stock without reflesh, Should I be getting 9.5 AFR? WOT?
What about Idle AFR? The will the Stock ECU still control the Idle AFR to 14.5?
(My idle is at 14.5 AFR right now)
14 AFR at WOT. If I switch to bigger injectors 440cc
from 300cc Stock without reflesh, Should I be getting 9.5 AFR? WOT?
What about Idle AFR? The will the Stock ECU still control the Idle AFR to 14.5?
(My idle is at 14.5 AFR right now)
01-10-2007, 06:02 AM
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Originally Posted by UnderPressure
Engine goes very lean.
Injectors are driven over a duration of time. With the larger injectors the pw was scaled back. Hence the stock injectors will be open for a shorter duration, equaling less fuel.
So don't do it basically.
Injectors are driven over a duration of time. With the larger injectors the pw was scaled back. Hence the stock injectors will be open for a shorter duration, equaling less fuel.
So don't do it basically.
01-10-2007, 07:02 AM
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Unfortunately the greatest engineering challenge in engine design is creating a smooth idle [while meeting emissions]. The dynamic range between 5 HP and 300HP is difficult to achieve.
OEM injectors don't even fully open at idle, just a tiny mist of fuel escapes.
Many times you must greatly increase idle speed to balance with the minimal flow from larger injectors.
OEM injectors don't even fully open at idle, just a tiny mist of fuel escapes.
Many times you must greatly increase idle speed to balance with the minimal flow from larger injectors.
01-10-2007, 10:59 AM
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Q45 Tech,
Do you know what's the Stock Injector size for 2005 G35x?
I did re-test on AFR today & it's
12.9 start
14.5 Idle
12.8 WOT,
Theses are pretty much exactly the same as before FI.
HKS think it's ok as the S/C is designed to run at stock AFR conditions.
My car Idle is sulky smooth with FI.
I can not tune the HKS S/C, It's fixed & It was designed for 03Z.
I am thinking, if I just plug in a 8% larger Injector from stock, change nothing else, I could be runing 13.3 ARF Idle & 11.8 AFR WOT.
That's 8% richer than NA mode. Would it be safer than now?
The car was running a bit lean stock. Only goes to 12.9 WOT & I am consearned 12.8 WOT FI is too lean.
Do you know what's the Stock Injector size for 2005 G35x?
I did re-test on AFR today & it's
12.9 start
14.5 Idle
12.8 WOT,
Theses are pretty much exactly the same as before FI.
HKS think it's ok as the S/C is designed to run at stock AFR conditions.
My car Idle is sulky smooth with FI.
I can not tune the HKS S/C, It's fixed & It was designed for 03Z.
I am thinking, if I just plug in a 8% larger Injector from stock, change nothing else, I could be runing 13.3 ARF Idle & 11.8 AFR WOT.
That's 8% richer than NA mode. Would it be safer than now?
The car was running a bit lean stock. Only goes to 12.9 WOT & I am consearned 12.8 WOT FI is too lean.
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