How does one go about adjusting a known, tested tune for larger injectors? I've been told that timing is one thing that kills motors, and by installing larger injectors, you can adjust the timing down and help save the motor. Obviously, if you get HUGE power, you might break someting, but it seems like the motor is more likely to survive at say 500RWHP with larger injectors and less timing and PW than huge PW and timing. At the moment, I'm not planning to go that route, although if having the nozzles honed is not too expensive and it actually can help extend the motor's live at say 500RWHP (when I figure out where my rail pressure is going, I should be near or over there) with timing and PW reduction, I probably would look into saving to have it done. I've also heard it said that a shorter pulsewidth will also help reduce EGT's which would be a BIG plus.
LLY: Adjusting tunes for bigger injectors
- Thread starter Cougar281
- Start date
i tend to agree in theory with what you say, but have no evidence to back it up. the only problem i see with bigger tips is they will drain you rail quicker and produce less atomization. but there are plenty of people running them and have no issues.
You need Nicks CP rig to make this a useful discussion. IMO, each vehicle must be tuned individually using this important information, to optimize LPP, normally to 12 ATDC.
Everything else is just a guess.
Everything else is just a guess.
Location of Peak Pressure, on the CP chart. Internal combustion engines are mostly the same, geometry wise. The stroke analysis, broken down typically yields max net positive torque (pos torque minus neg torque) when timing is such that LPP is about -12 BTDC
Timing
Killerbee, Do you not think that there is other factors that play into whats best? Do you think rod ratio cahnges anything? Shorter rods have less dwell time at TDC, and longer rods has more. Jeff
Killerbee, Do you not think that there is other factors that play into whats best? Do you think rod ratio cahnges anything? Shorter rods have less dwell time at TDC, and longer rods has more. Jeff
it is an empirical design thing. It may be less than or more than 12. But not much different. Manufacturers target this range specifically.
Though I am no expert on ignition design. Experimentally, this could be determined with a rolling road dyno. Others may have something to add. We're all learning. JMO
Though I am no expert on ignition design. Experimentally, this could be determined with a rolling road dyno. Others may have something to add. We're all learning. JMO
GMC_2002_Dmax
The Still Master
Unfortunately there is no standard answer to this question.
Each truck requires a special tune in my experience, what works on one truck doesn't work on another.
Volker is right about pulse width and pressure at idle, he proved it to me the first time I tuned Nasty at Danville in 2007. We tried the standard way of thinking with the Roadrunner in real time and his way, he was correct.
I have had to jack up pulse width and pressure on a few trucks, but when properly tunes you can't beat bigger sticks.