Tuning for 90hp injectors ?

[mstordahl]

Thanks Rich, I was refering to timing and not all the other variables.

[DoghouseDiesel]

Reducing the timing will shift the main event later in the cycle and will retain more heat energy to spool the turbo.

The quicker it's lit, the quicker that smoke is gone and the more responsive the engine is.

It's a double edged sword though. Timing is power. The more you can advance the timing, the more power the engine generates, but the EGT's will be cooler and the less boost the turbo produces.

Retard the timing too much and the motor is sluggish. -2 to 5 degrees seems to do well on most trucks in those lower RPM's.

The other thing you notice with these low timing numbers is almost no rattle, especially if the timing is AFTER TDC. 0 to -2 degrees at idle through 1000 RPM and there nearly no rattle.

[mstordahl]

Great info Rich, that is exactly how I understood it as well, thanks for clarifying. Like most things, its give and take, nothing is free.

Thanks again, this kind of info really helps others along and makes the product look better. Any person can use a tool, but it takes some know how to use it to its best.

[AH64ID]

For example, in my truck, most of my daily driving is in the 30 - 70mm3 range and up to 110MPa on the rail pressure, that's where I focus on for smoke control. 70mm3 - 110mm3 is mostly passing / harder acceleration and anything above that I consider WOT anyways.

Since I am sure you are running a lot more fuel than that in reality, you just leave the OE mm3 range in and increase the duration and the ECM thinks your only injecting that amount?

[DoghouseDiesel]

Remember, the mm3's in the case are not a real value, it's just a reference.

Change anything in duration or pressure and you wouldn't have an accurate cubic millimeter value if that was the case.

My mm3 values are modified, as are my rail pressure values, so they allow me to be more accurate in the daily driving ranges and less so in the WOT and idle ranges. For example, from 40 - 60 mm3 I advance the scale by 2 versus from 100 to 145 I advance the scale by 15.

[AH64ID]

So you have modified your timing/duration and mm3 reference tables?

Max OE mm3 is 140 correct?

[DoghouseDiesel]

Correct.

[icem237]

Rich when trying to build bottom end power, i raise duraion up till i hit a point where it will feel really strong , still clean , but it will idle rough just a bit at idle. I dont change anything in the idle range. timing doesnt change the rough transistion from idle to acceleration. So i try to lower the duration back down and that will work but the point where the rough feeling moves further out up the rpm range. I cant seem to put 2 and 2 together as to what im doing wrong. I know this might not make total sense but i think its just a basic error that right in front of me but lol im just not getting it.

[DoghouseDiesel]

Down low, don't worry too much about the duration....get the pressure to ramp in faster. This will smooth that out a bit.

Save the duration for higher in the RPM range.

What you're going to find is that in the lower RPM range, you're going to be lowering the duration values. You're going the wrong way by raising them up. The only reason to raise them is to fool the engine into thinking you have larger injectors than you really do.....sort of. You'll get better results if you ramp in the rail pressure a little faster here vs trying to bring in duration.

[icem237]

Down low, don't worry too much about the duration....get the pressure to ramp in faster. This will smooth that out a bit.

Save the duration for higher in the RPM range.

What you're going to find is that in the lower RPM range, you're going to be lowering the duration values. You're going the wrong way by raising them up. The only reason to raise them is to fool the engine into thinking you have larger injectors than you really do.....sort of. You'll get better results if you ramp in the rail pressure a little faster here vs trying to bring in duration.

Makes perfect sense! I knew it was simpler than what i making it , in my head anyway. Thanks!