Peak torque will not always occur at max fuel flow rate !

It all depends on what size your injectors are compared to how much fuel you need to deliver, along with the compromise of how much additional fuel for transients and cylinder cooling etc...

It is maxed when the injection pulse time is greater than the time available between the points at which one pulse starts to when the next pulse starts.
This is quantified by a term called "duty ratio".

Any more than 100% and the injectors are continuously open and we CANNOT give any more fuel !

Different duty values can occur at different RPMs/Boosts etc depending on the mapping.

Injectors ideally should never go above 80% but this rarely happens ...LOL
(Stage 1 and Stage 3 conversions offten max out 100% )

Manufacturers tend to aim for 80% which is why basic remaps can increase power nicely


Duty ratio is calculated..... (for fully sequential injection 4 cylinders)


DUTY_RATIO % = (INJECTION_TIME / RPM_TIME ) * 100

Where RPM_TIME= (1 / (RPM / 60)) * 2000

[RPM_TIME and INJECTION_TIME are expressed as milliseconds]


An example.... (rough values)

803's at normal fuel pressure deliver around 360 bhp at 20 milliseconds pulse duration.
(This is a higher BHP than you though but as you have less RPM time the BHP will be less)

At 6000 rpm there is ONLY 20 milliseconds available maximum
Any more boost or RPM will lean off the mixture no matter what !

At 5000 rpm, we have more time to deliver fuel (24 milliseconds)

At 7000 rpm, we have less time to deliver fuel (17 milliseconds)

So on a normal stage 3 conversion, running more boost or higher RPMS will lean out the engine !

I hope this explains it ...LOL


SOMEONE PLEASE GIVE ME A JOB..... LOL