Join Date: Sep 2008
Location: Oakbank, Manitoba
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Most high power tunes deliver a PW of about 2.7ms at mid-high RPM and ICP. 2.7 PW at about 3200rpm is pretty darn close to the fuel wall for stock nozzles. It doesn't matter what the injector core size is, fuel delivery is only a function of time (PW), pressure and much fuel you can flow (nozzle) in the limits of time. If your PW is less than 2.7ms, you are not delivering the maximum fuel available via tuning FICM or PCM) with stock nozzles. If you want more fuel, you need larger nozzles and a bigger injector core beyond this. Dumping a bit more fuel earlier, will help spool the charger, but it increases the heat and possibly smoke.
As an example, at 3500 rpm, the crank turns 0.0583 revs/ms or about 21 degrees. If you have been reading up on diesel engines, the sweet spot for best max cylinder pressure is 15-20* ATDC. To achieve this, the injectors have to start delivering fuel at some point before TDC and should almost be finished by 20*. It could continue as long as 70* with diminishing power returns and extra heat. So if start of injection was at 10* BTDC and ignition was just prior to TDC, and injection lasted 3.0 ms, EOI would be 53* ATDC, well past the ideal point. That would be one hot load and need a large charger to keep the temps under control, but the cylinder pressure would be fairly safe.
Torque and HP remain strictly a function of fuel and air in the ideal mix. If it is not balanced the result will not be optimized. Does the Atlas 80 help with the SRLxxx? The real question should be how much, since the tune is already dumping near max fuel.