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Max Duty!

Old 05-09-14, 11:08 PM
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Max Duty!

He guys a little bit of background with my build. Car is running on pump E85 with 1000cc Primaries 1600cc secondaries nippodenso TT supra pump (340LPH) -6 lines all around, parallel fuel rails S5 large streetport , turbo is an ebay charger .70 compressor .68 hotside ecu microtech lt8.

Went out to tune for a little bit more boost 18 psi(ish) and raised my revcut from 8150 to 8440. Had previously been running the car at 12psi for a racing season.
I did a few logs while playing with boost and here are screenshots from the logs.

The car ran around +-~86 lambda (its fubared in microtech) and when I tried to add more fuel it did not seem to change.

After viewing the logs closely I saw the "MaxDuty" warning for the first times and at slightly random mS Values.

My question is How exactly does the microtech come up with the warning of MaxDuty? Hopefully with an explanation I can help determine what exactly is the bottleneck of my fuel system.

Fuel pressure is a base pressure of ~38.
Attached Thumbnails Max Duty!-maxduty-16psi.jpg   Max Duty!-maxduty-20psi.jpg  
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Old 05-09-14, 11:28 PM
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Your 1000 and 1600 set up should only be good for under 500rwhp on E85 on a rotary if everything is optimal (pump not dropping pressure, AFRs on target, low stock like peak torque rpm, etc.)

At 18psi you are pushing it too far for your fuel system.

Duty cycle is calculated from injector ms pulsewidth, rpm and how may shaft revolutions till the injector fires.

If you search online you should be able to find a lookup table, I know my Haltech manual has one in it.
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