Big Injector timing
- Thread starter x MadMAX DIESEL
- Start date
Ben, the timing calc won't work on an iPad or anything Apple. You need a Windows based OS with Microsoft Excel installed. It's in spreadsheet form.
Yah ill have to try it agin on the laptop tonight. If not ill see if can use another computer somewherre
You are correct. You can set desired percentage in top left corner and after you run your current numbers it will tell you what you need to reach desired percentage. You would then have to blend and smooth after you paste those tables. You can also use the bottom table of the spreadsheet to input desired percentages at lower mm3 and pressures to get t hi ode numbers if you want to.
Too much timing sprays the fuel on the cylinder walls and melts pistons as well. It's all about getting things in the right combination. Moderation my friend kit extreme.
Can you add a large pilot before your main injection? Every short dwell time between the two injections. is Your rail pressure 2000 bar? If not Can you increase the currant to the prv ( 2nd fuelregulator)? This will allow the meterng valve to control rail pressure.
In cases, like these, once your over 2800rpm pilot is shut off and all of your injection is controlled by main injection pulse
60x-2. Is the reluctor wheel count takes 720 degrees for a 1 combustion process, four injections every 360degrees for cranks rotation. Every 90 degrees cylinder sees compression stroke TDC, you need to calculate how long in takes for the cylinder to reach TDC from BDC on the compression stroke to see if theres enough time to energize the injector for a givin rpm so you can avoid washing the cylinder and creating turbalance. Once you know That you can factor in rail pressure for fine tuning.
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You can control pilot 1 pilot 2 post1 and main inj pulse with it, when they all shut off. You must not be aware of the high performance side of the tuning on these
You seem like a smart fella I'm glad you came in this thread. But rail pressures always full bore in every truck I'm in lol
Table of micro-seconds vs. crank angle degrees
1000us takes 6 degrees of crank angle at 1000rpm
1000us takes 12 degree of crank angle at 2000rpm
1000us takes 18 degree of crank angle at 3000rpm
1000us takes 24 degree of crank angle at 4000rpm
1000us takes 30 degree of crank angle at 5000rpm
2000us takes 12 degree to inject at 1000rpm
2000us takes 24 degree to inject at 2000rpm
2000us takes 36 degree to inject at 3000rpm
2000us takes 48 degree to inject at 4000rpm
2000us takes 60 degree to inject at 5000rpm
Big injectors are useful at higher rpm. Big injectors allow a shorter fuel duration. The duration needs to be shorter at higher rpm because everything is happening faster. They do throw the fuel in at at faster rate. Without faster fuel delivery, the fuel will never burn during the power stroke or even be delivered during the power stroke.
Less fuel might make more power if injected at the proper time. More fuel can smother the fire and take longer to light...Diesel takes a while to light and more Diesel can take longer to ignite.
1000us takes 6 degrees of crank angle at 1000rpm
1000us takes 12 degree of crank angle at 2000rpm
1000us takes 18 degree of crank angle at 3000rpm
1000us takes 24 degree of crank angle at 4000rpm
1000us takes 30 degree of crank angle at 5000rpm
2000us takes 12 degree to inject at 1000rpm
2000us takes 24 degree to inject at 2000rpm
2000us takes 36 degree to inject at 3000rpm
2000us takes 48 degree to inject at 4000rpm
2000us takes 60 degree to inject at 5000rpm
Big injectors are useful at higher rpm. Big injectors allow a shorter fuel duration. The duration needs to be shorter at higher rpm because everything is happening faster. They do throw the fuel in at at faster rate. Without faster fuel delivery, the fuel will never burn during the power stroke or even be delivered during the power stroke.
Less fuel might make more power if injected at the proper time. More fuel can smother the fire and take longer to light...Diesel takes a while to light and more Diesel can take longer to ignite.
Just math
1000us is 1/1000th of a second
1 rpm is 360 degree /minute
1 rpm is 6 degree/ second
1000rpm is 6000 degree/sec
But we are talking about 1000us (top line) is 1/1000th of a second
so
6000 degree/second for only 1/1000th of a sec gives only 6 degree of rotation
Engine is spinning quickly but injectors are only on for a short while.
I use the idea of 1000us at 1000rpm means 6 degree of rotation a lot when timing injectors.
1000us is 1/1000th of a second
1 rpm is 360 degree /minute
1 rpm is 6 degree/ second
1000rpm is 6000 degree/sec
But we are talking about 1000us (top line) is 1/1000th of a second
so
6000 degree/second for only 1/1000th of a sec gives only 6 degree of rotation
Engine is spinning quickly but injectors are only on for a short while.
I use the idea of 1000us at 1000rpm means 6 degree of rotation a lot when timing injectors.
GMC_2002_Dmax
The Still Master
No matter what rpm the engine is spinning the injector still dwells open for "X" microseconds.
The injector dwell rate is static no matter what the rpm is, if you go WOT the injector will open for whatever time in microseconds that the table says, rpm has nothing to do with it unless the microseconds commanded are different values at different rpms.
If you used the CADEG PID just as I suggested it will tell you that at "X" microseconds it took this many degrees of crank rotation to inject that amount of fuel.
It will also tell you at what point BTDC it opened and the total duration it was open.
From memory a 3000US shot takes about 64-68 total degrees to inject, if you run 32 degrees timing at 3400 rpms it will roughly split the BTDC and ATDC fueling, essentially chasing the piston down the bore for more than 1/2 the duration.
The one thing everyone always overlooks is that 1500US with a 100% over is not the same amount of fuel as 1500us with a standard injector, so the timing calculators are worthless IMHO.
Time/Pressure/Orifice, only time and pressure we have control over.
:thumb:
The injector dwell rate is static no matter what the rpm is, if you go WOT the injector will open for whatever time in microseconds that the table says, rpm has nothing to do with it unless the microseconds commanded are different values at different rpms.
If you used the CADEG PID just as I suggested it will tell you that at "X" microseconds it took this many degrees of crank rotation to inject that amount of fuel.
It will also tell you at what point BTDC it opened and the total duration it was open.
From memory a 3000US shot takes about 64-68 total degrees to inject, if you run 32 degrees timing at 3400 rpms it will roughly split the BTDC and ATDC fueling, essentially chasing the piston down the bore for more than 1/2 the duration.
The one thing everyone always overlooks is that 1500US with a 100% over is not the same amount of fuel as 1500us with a standard injector, so the timing calculators are worthless IMHO.
Time/Pressure/Orifice, only time and pressure we have control over.
:thumb:
Yeah I got the math figured out and changed my tuning for a little test lastnight. It didn't work out very well for my end. Lost alot of power from the drivers seat, havent checked the logs yet. I will have to add the crankangledegree pid though, that seems nifty :thumb:
I decreased it quite a bit. Ran like a 40/60 split. I dont want to answer for Tony, but I assume it will tell the total degree SOI to EOI and display that in the log.